Guide to the Secure Configuration of Amazon Linux 2023 | OpenSCAP Security Guide

## Guide to the Secure Configuration of Amazon Linux 2023

> with profile CIS Amazon Linux 2023 Benchmark for Level 2 - Server
> This profile defines a baseline that aligns to the "Level 2 - Server" configuration from the Center for Internet Security® Amazon Linux 2023 Benchmark™, v1.0.0, released 2023-06-26. This profile includes Center for Internet Security® Amazon Linux 2023 CIS Benchmarks™ content.

The SCAP Security Guide Project
https://www.open-scap.org/security-policies/scap-security-guide
This guide presents a catalog of security-relevant configuration settings for Amazon Linux 2023. It is a rendering of content structured in the eXtensible Configuration Checklist Description Format (XCCDF) in order to support security automation. The SCAP content is is available in the `scap-security-guide` package which is developed at https://www.open-scap.org/security-policies/scap-security-guide.
Providing system administrators with such guidance informs them how to securely configure systems under their control in a variety of network roles. Policy makers and baseline creators can use this catalog of settings, with its associated references to higher-level security control catalogs, in order to assist them in security baseline creation. This guide is a catalog, not a checklist, and satisfaction of every item is not likely to be possible or sensible in many operational scenarios. However, the XCCDF format enables granular selection and adjustment of settings, and their association with OVAL and OCIL content provides an automated checking capability. Transformations of this document, and its associated automated checking content, are capable of providing baselines that meet a diverse set of policy objectives. Some example XCCDF Profiles, which are selections of items that form checklists and can be used as baselines, are available with this guide. They can be processed, in an automated fashion, with tools that support the Security Content Automation Protocol (SCAP). The DISA STIG, which provides required settings for US Department of Defense systems, is one example of a baseline created from this guidance.
Do not attempt to implement any of the settings in this guide without first testing them in a non-operational environment. The creators of this guidance assume no responsibility whatsoever for its use by other parties, and makes no guarantees, expressed or implied, about its quality, reliability, or any other characteristic.

## Profile Information

Profile Title | CIS Amazon Linux 2023 Benchmark for Level 2 - Server
Profile ID | xccdf_org.ssgproject.content_profile_cis

#### CPE Platforms

- cpe:/o:amazon:amazon_linux:2023

## Revision History

Current version: 0.1.80

- draft (as of 2026-03-06)

## Table of Contents

1. System Settings
   1. Installing and Maintaining Software
   2. Account and Access Control
   3. GRUB2 bootloader configuration
   4. Configure Syslog
   5. Network Configuration and Firewalls
   6. File Permissions and Masks
   7. SELinux
2. Services
   1. Avahi Server
   2. Cron and At Daemons
   3. DHCP
   4. DNS Server
   5. FTP Server
   6. Web Server
   7. IMAP and POP3 Server
   8. LDAP
   9. Mail Server Software
   10. NFS and RPC
   11. Network Time Protocol
   12. Obsolete Services
   13. Print Support
   14. Proxy Server
   15. Samba(SMB) Microsoft Windows File Sharing Server
   16. SNMP Server
   17. SSH Server
   18. X Window System
3. System Accounting with auditd
   1. Configure auditd Rules for Comprehensive Auditing
   2. Configure auditd Data Retention
   3. System Accounting with auditd

## Checklist

Group Guide to the Secure Configuration of Amazon Linux 2023 Group contains 106 groups and 356 rules
Group System Settings Group contains 50 groups and 200 rules
[ref] Contains rules that check correct system settings.
Group Installing and Maintaining Software Group contains 7 groups and 18 rules
[ref] The following sections contain information on security-relevant choices during the initial operating system installation process and the setup of software updates.
Group System and Software Integrity Group contains 3 groups and 6 rules
[ref] System and software integrity can be gained by installing antivirus, increasing system encryption strength with FIPS, verifying installed software, enabling SELinux, installing an Intrusion Prevention System, etc. However, installing or enabling integrity checking tools cannot prevent intrusions, but they can detect that an intrusion may have occurred. Requirements for integrity checking may be highly dependent on the environment in which the system will be used. Snapshot-based approaches such as AIDE may induce considerable overhead in the presence of frequent software updates.
Group Software Integrity Checking Group contains 1 group and 4 rules
[ref] Both the AIDE (Advanced Intrusion Detection Environment) software and the RPM package management system provide mechanisms for verifying the integrity of installed software. AIDE uses snapshots of file metadata (such as hashes) and compares these to current system files in order to detect changes. The RPM package management system can conduct integrity checks by comparing information in its metadata database with files installed on the system.
Group Verify Integrity with AIDE Group contains 4 rules
[ref] AIDE conducts integrity checks by comparing information about files with previously-gathered information. Ideally, the AIDE database is created immediately after initial system configuration, and then again after any software update. AIDE is highly configurable, with further configuration information located in `/usr/share/doc/aide-VERSION` .
#### Rule Install AIDE [ref]
The `aide` package can be installed with the following command:
    $ sudo dnf install aide
Rationale: | The AIDE package must be installed if it is to be available for integrity checking.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_package_aide_installed
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9
cjis | 5.10.1.3
cobit5 | APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06
isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4
isa-62443-2013 | SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6
iso27001-2013 | A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3
nist | CM-6(a)
nist-csf | DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3
pcidss | Req-11.5
os-srg | SRG-OS-000445-GPOS-00199
anssi | R76, R79
cis | 1.3.1
ism | 1034, 1288, 1341, 1417
pcidss4 | 11.5.2
Remediation OSBuild Blueprint snippet ⇲
    [[packages]]
    name = "aide"
    version = "*"
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if ! rpm -q --quiet "aide" ; then
        dnf install -y "aide"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    package --add=aide
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.1.3
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_aide_installed

    - name: Ensure aide is installed
      ansible.builtin.package:
        name: aide
        state: present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.3
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_aide_installed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include install_aide

    class install_aide {
      package { 'aide':
        ensure => 'installed',
      }
    }
#### Rule Build and Test AIDE Database [ref]
Run the following command to generate a new database:
    $ sudo /usr/sbin/aide --init
By default, the database will be written to the file `/var/lib/aide/aide.db.new.gz`. Storing the database, the configuration file `/etc/aide.conf`, and the binary `/usr/sbin/aide` (or hashes of these files), in a secure location (such as on read-only media) provides additional assurance about their integrity. The newly-generated database can be installed as follows:
    $ sudo cp /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz
To initiate a manual check, run the following command:
    $ sudo /usr/sbin/aide --check
If this check produces any unexpected output, investigate. Warning: In RHEL Image Mode (bootc) systems, the AIDE database must be regenerated after each system update. Image Mode systems receive updates through new container images that may include modified files. After applying system updates, run the following commands to regenerate the AIDE database:
    $ sudo /usr/sbin/aide --init
Then replace the existing database:
    $ sudo cp /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz
Failure to regenerate the AIDE database after updates will result in false positive alerts for legitimate system changes introduced by the update process.
Rationale: | For AIDE to be effective, an initial database of "known-good" information about files must be captured and it should be able to be verified against the installed files.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_aide_build_database
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9
cjis | 5.10.1.3
cobit5 | APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06
isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4
isa-62443-2013 | SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6
iso27001-2013 | A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3
nist | CM-6(a)
nist-csf | DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3
pcidss | Req-11.5
os-srg | SRG-OS-000445-GPOS-00199
anssi | R76, R79
cis | 1.3.1
pcidss4 | 11.5.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if ! rpm -q --quiet "aide" ; then
        dnf install -y "aide"
    fi

    /usr/sbin/aide --init
    /bin/cp -p /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.1.3
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - aide_build_database
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Build and Test AIDE Database - Ensure AIDE Is Installed
      ansible.builtin.package:
        name: '{{ item }}'
        state: present
      with_items:
      - aide
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.3
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - aide_build_database
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Build and Test AIDE Database - Check Whether the Stock AIDE Database Exists
      ansible.builtin.stat:
        path: /var/lib/aide/aide.db.new.gz
      register: aide_database_stat
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.3
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - aide_build_database
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Build and Test AIDE Database - Build and Test AIDE Database
      ansible.builtin.command: /usr/sbin/aide --init
      changed_when: true
      when:
      - '"kernel" in ansible_facts.packages'
      - not (aide_database_stat.stat.exists is defined and aide_database_stat.stat.exists)
      register: aide_database_init
      tags:
      - CJIS-5.10.1.3
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - aide_build_database
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Build and Test AIDE Database - Stage AIDE Database
      ansible.builtin.copy:
        src: /var/lib/aide/aide.db.new.gz
        dest: /var/lib/aide/aide.db.gz
        backup: true
        remote_src: true
      when:
      - '"kernel" in ansible_facts.packages'
      - aide_database_init is changed
      - not ansible_check_mode
      tags:
      - CJIS-5.10.1.3
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - aide_build_database
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Configure AIDE to Verify the Audit Tools [ref]
The operating system file integrity tool must be configured to protect the integrity of the audit tools.
Rationale: | Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Audit tools include but are not limited to vendor-provided and open-source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. It is not uncommon for attackers to replace the audit tools or inject code into the existing tools to provide the capability to hide or erase system activity from the audit logs. To address this risk, audit tools must be cryptographically signed to provide the capability to identify when the audit tools have been modified, manipulated, or replaced. An example is a checksum hash of the file or files.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_aide_check_audit_tools
References: |
nist | AU-9(3), AU-9(3).1
os-srg | SRG-OS-000278-GPOS-00108
cis | 1.3.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if ! rpm -q --quiet "aide" ; then
        dnf install -y "aide"
    fi

    if grep -i -E '^.*(/usr)?/sbin/auditctl.*$' /etc/aide.conf; then
    sed -i -r "s#.*(/usr)?/sbin/auditctl.*#/usr/sbin/auditctl p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
    else
    echo "/usr/sbin/auditctl p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
    fi

    if grep -i -E '^.*(/usr)?/sbin/auditd.*$' /etc/aide.conf; then
    sed -i -r "s#.*(/usr)?/sbin/auditd.*#/usr/sbin/auditd p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
    else
    echo "/usr/sbin/auditd p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
    fi

    if grep -i -E '^.*(/usr)?/sbin/ausearch.*$' /etc/aide.conf; then
    sed -i -r "s#.*(/usr)?/sbin/ausearch.*#/usr/sbin/ausearch p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
    else
    echo "/usr/sbin/ausearch p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
    fi

    if grep -i -E '^.*(/usr)?/sbin/aureport.*$' /etc/aide.conf; then
    sed -i -r "s#.*(/usr)?/sbin/aureport.*#/usr/sbin/aureport p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
    else
    echo "/usr/sbin/aureport p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
    fi

    if grep -i -E '^.*(/usr)?/sbin/autrace.*$' /etc/aide.conf; then
    sed -i -r "s#.*(/usr)?/sbin/autrace.*#/usr/sbin/autrace p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
    else
    echo "/usr/sbin/autrace p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
    fi

    if grep -i -E '^.*(/usr)?/sbin/augenrules.*$' /etc/aide.conf; then
    sed -i -r "s#.*(/usr)?/sbin/augenrules.*#/usr/sbin/augenrules p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
    else
    echo "/usr/sbin/augenrules p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
    fi

    if grep -i -E '^.*(/usr)?/sbin/audispd.*$' /etc/aide.conf; then
    sed -i -r "s#.*(/usr)?/sbin/audispd.*#/usr/sbin/audispd p+i+n+u+g+s+b+acl+selinux+xattrs+sha512#" /etc/aide.conf
    else
    echo "/usr/sbin/audispd p+i+n+u+g+s+b+acl+selinux+xattrs+sha512" >> /etc/aide.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AU-9(3)
      - NIST-800-53-AU-9(3).1
      - aide_check_audit_tools
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Configure AIDE to Verify the Audit Tools - Gather List of Packages
      tags:
      - NIST-800-53-AU-9(3)
      - NIST-800-53-AU-9(3).1
      - aide_check_audit_tools
      - aide_check_audit_tools
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      ansible.builtin.package_facts:
        manager: auto
      when: '"kernel" in ansible_facts.packages'

    - name: Configure AIDE to Verify the Audit Tools - Ensure AIDE is Installed
      ansible.builtin.package:
        name: '{{ item }}'
        state: present
      with_items:
      - aide
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AU-9(3)
      - NIST-800-53-AU-9(3).1
      - aide_check_audit_tools
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Configure AIDE to Verify the Audit Tools - Gather the Package Facts
      ansible.builtin.package_facts:
        manager: auto
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AU-9(3)
      - NIST-800-53-AU-9(3).1
      - aide_check_audit_tools
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set "Configure AIDE to Verify the Audit Tools - audit_tools fact"
      ansible.builtin.set_fact:
        audit_tools:
        - /usr/sbin/audispd
        - /usr/sbin/auditctl
        - /usr/sbin/auditd
        - /usr/sbin/augenrules
        - /usr/sbin/aureport
        - /usr/sbin/ausearch
        - /usr/sbin/autrace
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AU-9(3)
      - NIST-800-53-AU-9(3).1
      - aide_check_audit_tools
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Configure AIDE to Verify the Audit Tools - Ensure Existing AIDE Configuration
        for Audit Tools are Correct
      ansible.builtin.lineinfile:
        path: /etc/aide.conf
        regexp: ^{{ item }}\s
        line: '{{ item }} p+i+n+u+g+s+b+acl+selinux+xattrs+sha512'
        create: true
      with_items: '{{ audit_tools }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"aide" in ansible_facts.packages'
      tags:
      - NIST-800-53-AU-9(3)
      - NIST-800-53-AU-9(3).1
      - aide_check_audit_tools
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Configure AIDE to Verify the Audit Tools - Configure AIDE to Properly Protect
        Audit Tools
      ansible.builtin.lineinfile:
        path: /etc/aide.conf
        line: '{{ item }} p+i+n+u+g+s+b+acl+selinux+xattrs+sha512'
        create: true
      with_items: '{{ audit_tools }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"aide" in ansible_facts.packages'
      tags:
      - NIST-800-53-AU-9(3)
      - NIST-800-53-AU-9(3).1
      - aide_check_audit_tools
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Configure Periodic Execution of AIDE [ref]
At a minimum, AIDE should be configured to run a weekly scan. To implement a daily execution of AIDE at 4:05am using cron, add the following line to `/etc/crontab`:
    05 4 * * * root /usr/sbin/aide --check
To implement a weekly execution of AIDE at 4:05am using cron, add the following line to `/etc/crontab`:
    05 4 * * 0 root /usr/sbin/aide --check
AIDE can be executed periodically through other means; this is merely one example. The usage of cron's special time codes, such as `@daily` and `@weekly` is acceptable.
Rationale: | By default, AIDE does not install itself for periodic execution. Periodically running AIDE is necessary to reveal unexpected changes in installed files. Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's Information Management Officer (IMO)/Information System Security Officer (ISSO) and System Administrators (SAs) must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_aide_periodic_cron_checking
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 2, 3, 5, 7, 8, 9
cjis | 5.10.1.3
cobit5 | APO01.06, BAI01.06, BAI02.01, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS04.07, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.02, DSS06.06
isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4
isa-62443-2013 | SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 4.1, SR 6.2, SR 7.6
iso27001-2013 | A.11.2.4, A.12.1.2, A.12.2.1, A.12.4.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.7, A.15.2.1, A.8.2.3
nist | SI-7, SI-7(1), CM-6(a)
nist-csf | DE.CM-1, DE.CM-7, PR.DS-1, PR.DS-6, PR.DS-8, PR.IP-1, PR.IP-3
pcidss | Req-11.5
os-srg | SRG-OS-000363-GPOS-00150, SRG-OS-000446-GPOS-00200, SRG-OS-000447-GPOS-00201
anssi | R76
cis | 1.3.2
pcidss4 | 11.5.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if ! rpm -q --quiet "aide" ; then
        dnf install -y "aide"
    fi

    if ! rpm -q --quiet "cronie" ; then
        dnf install -y "cronie"
    fi

    CRON_FILE="/etc/crontab"

    if ! grep -q "/usr/sbin/aide --check" "${CRON_FILE}" ; then
        echo "05 4 * * * root /usr/sbin/aide --check" >> "${CRON_FILE}"
    else
        sed -i '\!^.* --check.*$!d' "${CRON_FILE}"
        echo "05 4 * * * root /usr/sbin/aide --check" >> "${CRON_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.1.3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SI-7
      - NIST-800-53-SI-7(1)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - aide_periodic_cron_checking
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Configure Periodic Execution of AIDE - Ensure AIDE is installed
      ansible.builtin.package:
        name: aide
        state: present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SI-7
      - NIST-800-53-SI-7(1)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - aide_periodic_cron_checking
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Configure Periodic Execution of AIDE - Install cron
      ansible.builtin.package:
        name: cronie
        state: present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SI-7
      - NIST-800-53-SI-7(1)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - aide_periodic_cron_checking
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Configure Periodic Execution of AIDE - Gather List of Installed Packages
      ansible.builtin.package_facts:
        manager: auto
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SI-7
      - NIST-800-53-SI-7(1)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - aide_periodic_cron_checking
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Configure Periodic Execution of AIDE - Setup Cron Tab
      ansible.builtin.cron:
        name: run AIDE check
        minute: 5
        hour: 4
        user: root
        job: /usr/sbin/aide --check
      register: crontab_check
      when:
      - '"kernel" in ansible_facts.packages'
      - '''cronie'' in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SI-7
      - NIST-800-53-SI-7(1)
      - PCI-DSS-Req-11.5
      - PCI-DSSv4-11.5.2
      - aide_periodic_cron_checking
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
Group System Cryptographic Policies Group contains 2 rules
[ref] Linux has the capability to centrally configure cryptographic polices. The command `update-crypto-policies` is used to set the policy applicable for the various cryptographic back-ends, such as SSL/TLS libraries. The configured cryptographic policies will be the default policy used by these backends unless the application user configures them otherwise. When the system has been configured to use the centralized cryptographic policies, the administrator is assured that any application that utilizes the supported backends will follow a policy that adheres to the configured profile. Currently the supported backends are: GnuTLS library OpenSSL library NSS library OpenJDK Libkrb5 BIND OpenSSH Applications and languages which rely on any of these backends will follow the system policies as well. Examples are apache httpd, nginx, php, and others.
#### Rule Configure System Cryptography Policy [ref]
To configure the system cryptography policy to use ciphers only from the `DEFAULT` policy, run the following command:
    $ sudo update-crypto-policies --set DEFAULT
The rule checks if settings for selected crypto policy are configured as expected. Configuration files in the `/etc/crypto-policies/back-ends` are either symlinks to correct files provided by Crypto-policies package or they are regular files in case crypto policy customizations are applied. Crypto policies may be customized by crypto policy modules, in which case it is delimited from the base policy using a colon. Warning: The system needs to be rebooted for these changes to take effect. Warning: System Crypto Modules must be provided by a vendor that undergoes FIPS-140 certifications. FIPS-140 is applicable to all Federal agencies that use cryptographic-based security systems to protect sensitive information in computer and telecommunication systems (including voice systems) as defined in Section 5131 of the Information Technology Management Reform Act of 1996, Public Law 104-106. This standard shall be used in designing and implementing cryptographic modules that Federal departments and agencies operate or are operated for them under contract. See https://nvlpubs.nist.gov/nistpubs/FIPS/NIST.FIPS.140-2.pdf To meet this, the system has to have cryptographic software provided by a vendor that has undergone this certification. This means providing documentation, test results, design information, and independent third party review by an accredited lab. While open source software is capable of meeting this, it does not meet FIPS-140 unless the vendor submits to this process.
Rationale: | Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of utilizing encryption to protect data.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_configure_crypto_policy
References: |
hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.312(e)(1), 164.312(e)(2)(ii)
nerc-cip | CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1
nist | AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13, SC-12(2), SC-12(3)
ospp | FCS_COP.1(1), FCS_COP.1(2), FCS_COP.1(3), FCS_COP.1(4), FCS_CKM.1, FCS_CKM.2, FCS_TLSC_EXT.1
os-srg | SRG-OS-000396-GPOS-00176, SRG-OS-000393-GPOS-00173, SRG-OS-000394-GPOS-00174
cis | 1.9
ism | 1446
pcidss4 | 2.2.7, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    var_system_crypto_policy='DEFAULT'

    stderr_of_call=$(update-crypto-policies --set ${var_system_crypto_policy} 2>&1 > /dev/null)
    rc=$?

    if test "$rc" = 127; then
    	echo "$stderr_of_call" >&2
    	echo "Make sure that the script is installed on the remediated system." >&2
    	echo "See output of the 'dnf provides update-crypto-policies' command" >&2
    	echo "to see what package to (re)install" >&2

    	false  # end with an error code
    elif test "$rc" != 0; then
    	echo "Error invoking the update-crypto-policies script: $stderr_of_call" >&2
    	false  # end with an error code
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: XCCDF Value var_system_crypto_policy # promote to variable
      set_fact:
        var_system_crypto_policy: !!str DEFAULT
      tags:
        - always

    - name: Configure System Cryptography Policy - Check current crypto policy (runtime)
      ansible.builtin.command: /usr/bin/update-crypto-policies --show
      register: current_crypto_policy
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - NIST-800-53-AC-17(2)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-MA-4(6)
      - NIST-800-53-SC-12(2)
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SC-13
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.7
      - configure_crypto_policy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy

    - name: Configure System Cryptography Policy - Get mtime of /etc/crypto-policies/config
      ansible.builtin.stat:
        path: /etc/crypto-policies/config
      register: config_file_stat
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - NIST-800-53-AC-17(2)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-MA-4(6)
      - NIST-800-53-SC-12(2)
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SC-13
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.7
      - configure_crypto_policy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy

    - name: Configure System Cryptography Policy - Get mtime of /etc/crypto-policies/state/current
      ansible.builtin.stat:
        path: /etc/crypto-policies/state/current
      register: current_file_stat
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - NIST-800-53-AC-17(2)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-MA-4(6)
      - NIST-800-53-SC-12(2)
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SC-13
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.7
      - configure_crypto_policy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy

    - name: Configure System Cryptography Policy - Check existence of /etc/crypto-policies/back-ends/nss.config
      ansible.builtin.stat:
        path: /etc/crypto-policies/back-ends/nss.config
      register: nss_config_stat
      changed_when: false
      failed_when: false
      check_mode: false
      tags:
      - NIST-800-53-AC-17(2)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-MA-4(6)
      - NIST-800-53-SC-12(2)
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SC-13
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.7
      - configure_crypto_policy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy

    - name: Configure System Cryptography Policy - Verify that Crypto Policy is Set (runtime)
      ansible.builtin.command: /usr/bin/update-crypto-policies --set {{ var_system_crypto_policy
        }}
      when: (current_crypto_policy.stdout.strip() != var_system_crypto_policy) or (config_file_stat.stat.exists
        and current_file_stat.stat.exists and config_file_stat.stat.mtime > current_file_stat.stat.mtime)
        or (not nss_config_stat.stat.exists)
      tags:
      - NIST-800-53-AC-17(2)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-MA-4(6)
      - NIST-800-53-SC-12(2)
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SC-13
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.7
      - configure_crypto_policy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
#### Rule Configure SSH to use System Crypto Policy [ref]
Crypto Policies provide a centralized control over crypto algorithms usage of many packages. SSH is supported by crypto policy, but the SSH configuration may be set up to ignore it. To check that Crypto Policies settings are configured correctly, ensure that the `CRYPTO_POLICY` variable is either commented or not set at all in the `/etc/sysconfig/sshd`.
Rationale: | Overriding the system crypto policy makes the behavior of the SSH service violate expectations, and makes system configuration more fragmented.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_configure_ssh_crypto_policy
References: |
hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.312(e)(1), 164.312(e)(2)(ii)
nerc-cip | CIP-003-8 R4.2, CIP-007-3 R5.1, CIP-007-3 R7.1
nist | AC-17(a), AC-17(2), CM-6(a), MA-4(6), SC-13
ospp | FCS_SSH_EXT.1, FCS_SSHS_EXT.1, FCS_SSHC_EXT.1
pcidss | Req-2.2
os-srg | SRG-OS-000250-GPOS-00093
cis | 4.2.14
ism | 0418
pcidss4 | 2.2.7, 2.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    SSH_CONF="/etc/sysconfig/sshd"

    sed -i "/^\s*CRYPTO_POLICY.*$/Id" $SSH_CONF

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-17(2)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-MA-4(6)
      - NIST-800-53-SC-13
      - PCI-DSS-Req-2.2
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.7
      - configure_ssh_crypto_policy
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required

    - name: Configure SSH to use System Crypto Policy
      ansible.builtin.lineinfile:
        dest: /etc/sysconfig/sshd
        state: absent
        regexp: (?i)^\s*CRYPTO_POLICY.*$
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-17(2)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-MA-4(6)
      - NIST-800-53-SC-13
      - PCI-DSS-Req-2.2
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.7
      - configure_ssh_crypto_policy
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
Group Disk Partitioning Group contains 7 rules
[ref] To ensure separation and protection of data, there are top-level system directories which should be placed on their own physical partition or logical volume. The installer's default partitioning scheme creates separate logical volumes for `/`, `/boot`, and `swap`. If starting with any of the default layouts, check the box to \"Review and modify partitioning.\" This allows for the easy creation of additional logical volumes inside the volume group already created, though it may require making `/`'s logical volume smaller to create space. In general, using logical volumes is preferable to using partitions because they can be more easily adjusted later. If creating a custom layout, create the partitions mentioned in the previous paragraph (which the installer will require anyway), as well as separate ones described in the following sections. If a system has already been installed, and the default partitioning scheme was used, it is possible but nontrivial to modify it to create separate logical volumes for the directories listed above. The Logical Volume Manager (LVM) makes this possible.
#### Rule Ensure /dev/shm is configured [ref]
The `/dev/shm` is a traditional shared memory concept. One program will create a memory portion, which other processes (if permitted) can access. If `/dev/shm` is not configured, tmpfs will be mounted to /dev/shm by systemd. Warning: This rule does not have a remediation. It is expected that this will be managed by systemd and will be a tmpfs partition.
Rationale: | Any user can upload and execute files inside the `/dev/shm` similar to the `/tmp` partition. Configuring `/dev/shm` allows an administrator to set the noexec option on the mount, making /dev/shm useless for an attacker to install executable code. It would also prevent an attacker from establishing a hardlink to a system setuid program and wait for it to be updated. Once the program was updated, the hardlink would be broken and the attacker would have his own copy of the program. If the program happened to have a security vulnerability, the attacker could continue to exploit the known flaw.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_dev_shm
References: |
cis | 1.1.8.1
#### Rule Ensure /home Located On Separate Partition [ref]
If user home directories will be stored locally, create a separate partition for `/home` at installation time (or migrate it later using LVM). If `/home` will be mounted from another system such as an NFS server, then creating a separate partition is not necessary at installation time, and the mountpoint can instead be configured later.
Rationale: | Ensuring that `/home` is mounted on its own partition enables the setting of more restrictive mount options, and also helps ensure that users cannot trivially fill partitions used for log or audit data storage.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_home
References: |
cis-csc | 12, 15, 8
cobit5 | APO13.01, DSS05.02
isa-62443-2013 | SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.13.1.1, A.13.2.1, A.14.1.3
nist | CM-6(a), SC-5(2)
nist-csf | PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R28
cis | 1.1.7.1
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /home
#### Rule Ensure /tmp Located On Separate Partition [ref]
The `/tmp` directory is a world-writable directory used for temporary file storage. Ensure it has its own partition or logical volume at installation time, or migrate it using LVM.
Rationale: | The `/tmp` partition is used as temporary storage by many programs. Placing `/tmp` in its own partition enables the setting of more restrictive mount options, which can help protect programs which use it.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_tmp
References: |
cis-csc | 12, 15, 8
cobit5 | APO13.01, DSS05.02
isa-62443-2013 | SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.13.1.1, A.13.2.1, A.14.1.3
nist | CM-6(a), SC-5(2)
nist-csf | PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
cis | 1.1.2.1
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /tmp
#### Rule Ensure /var Located On Separate Partition [ref]
The `/var` directory is used by daemons and other system services to store frequently-changing data. Ensure that `/var` has its own partition or logical volume at installation time, or migrate it using LVM.
Rationale: | Ensuring that `/var` is mounted on its own partition enables the setting of more restrictive mount options. This helps protect system services such as daemons or other programs which use it. It is not uncommon for the `/var` directory to contain world-writable directories installed by other software packages.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_var
References: |
cis-csc | 12, 15, 8
cobit5 | APO13.01, DSS05.02
isa-62443-2013 | SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.13.1.1, A.13.2.1, A.14.1.3
nist | CM-6(a), SC-5(2)
nist-csf | PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R28
cis | 1.1.3.1
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var
#### Rule Ensure /var/log Located On Separate Partition [ref]
System logs are stored in the `/var/log` directory. Ensure that `/var/log` has its own partition or logical volume at installation time, or migrate it using LVM.
Rationale: | Placing `/var/log` in its own partition enables better separation between log files and other files in `/var/`.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_var_log
References: |
cis-csc | 1, 12, 14, 15, 16, 3, 5, 6, 8
cobit5 | APO11.04, APO13.01, BAI03.05, DSS05.02, DSS05.04, DSS05.07, MEA02.01
isa-62443-2009 | 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3
nerc-cip | CIP-007-3 R6.5
nist | CM-6(a), AU-4, SC-5(2)
nist-csf | PR.PT-1, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R28
cis | 1.1.5.1
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var/log
#### Rule Ensure /var/log/audit Located On Separate Partition [ref]
Audit logs are stored in the `/var/log/audit` directory. Ensure that `/var/log/audit` has its own partition or logical volume at installation time, or migrate it using LVM. Make absolutely certain that it is large enough to store all audit logs that will be created by the auditing daemon.
Rationale: | Placing `/var/log/audit` in its own partition enables better separation between audit files and other files, and helps ensure that auditing cannot be halted due to the partition running out of space.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_var_log_audit
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 8
cobit5 | APO11.04, APO13.01, BAI03.05, BAI04.04, DSS05.02, DSS05.04, DSS05.07, MEA02.01
hipaa | 164.312(a)(2)(ii)
isa-62443-2009 | 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.17.2.1
nerc-cip | CIP-007-3 R6.5
nist | CM-6(a), AU-4, SC-5(2)
nist-csf | PR.DS-4, PR.PT-1, PR.PT-4
ospp | FMT_SMF_EXT.1
os-srg | SRG-OS-000341-GPOS-00132, SRG-OS-000480-GPOS-00227
app-srg-ctr | SRG-APP-000357-CTR-000800
anssi | R71
cis | 1.1.6.1
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var/log/audit
#### Rule Ensure /var/tmp Located On Separate Partition [ref]
The `/var/tmp` directory is a world-writable directory used for temporary file storage. Ensure it has its own partition or logical volume at installation time, or migrate it using LVM.
Rationale: | The `/var/tmp` partition is used as temporary storage by many programs. Placing `/var/tmp` in its own partition enables the setting of more restrictive mount options, which can help protect programs which use it.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_partition_for_var_tmp
References: |
os-srg | SRG-OS-000480-GPOS-00227
anssi | R28
cis | 1.1.4.1
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var/tmp
Group Sudo Group contains 4 rules
[ref] `Sudo`, which stands for "su 'do'", provides the ability to delegate authority to certain users, groups of users, or system administrators. When configured for system users and/or groups, `Sudo` can allow a user or group to execute privileged commands that normally only `root` is allowed to execute. For more information on `Sudo` and addition `Sudo` configuration options, see https://www.sudo.ws.
#### Rule Install sudo Package [ref]
The `sudo` package can be installed with the following command:
    $ sudo dnf install sudo
Rationale: | `sudo` is a program designed to allow a system administrator to give limited root privileges to users and log root activity. The basic philosophy is to give as few privileges as possible but still allow system users to get their work done.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_package_sudo_installed
References: |
nist | CM-6(a)
ospp | FMT_MOF_EXT.1
os-srg | SRG-OS-000324-GPOS-00125
anssi | R33
cis | 4.3.1
ism | 1386
pcidss4 | 2.2.6, 2.2
Remediation OSBuild Blueprint snippet ⇲
    [[packages]]
    name = "sudo"
    version = "*"
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if ! rpm -q --quiet "sudo" ; then
        dnf install -y "sudo"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    package --add=sudo
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_sudo_installed

    - name: Ensure sudo is installed
      ansible.builtin.package:
        name: sudo
        state: present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_sudo_installed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include install_sudo

    class install_sudo {
      package { 'sudo':
        ensure => 'installed',
      }
    }
#### Rule Ensure Only Users Logged In To Real tty Can Execute Sudo - sudo use_pty [ref]
The sudo `use_pty` tag, when specified, will only execute sudo commands from users logged in to a real tty. This should be enabled by making sure that the `use_pty` tag exists in `/etc/sudoers` configuration file or any sudo configuration snippets in `/etc/sudoers.d/`.
Rationale: | Requiring that sudo commands be run in a pseudo-terminal can prevent an attacker from retaining access to the user's terminal after the main program has finished executing.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sudo_add_use_pty
References: |
pcidss | Req-10.2.5
anssi | R39
cis | 4.3.2
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q sudo; }; then

    if /usr/sbin/visudo -qcf /etc/sudoers; then
        cp /etc/sudoers /etc/sudoers.bak
        if ! grep -P '^[\s]*Defaults\b[^!\n]*\buse_pty.*$' /etc/sudoers; then
            # sudoers file doesn't define Option use_pty
            echo "Defaults use_pty" >> /etc/sudoers
        fi

        # Check validity of sudoers and cleanup bak
        if /usr/sbin/visudo -qcf /etc/sudoers; then
            rm -f /etc/sudoers.bak
        else
            echo "Fail to validate remediated /etc/sudoers, reverting to original file."
            mv /etc/sudoers.bak /etc/sudoers
            false
        fi
    else
        echo "Skipping remediation, /etc/sudoers failed to validate"
        false
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sudo_add_use_pty

    - name: Ensure use_pty is enabled in /etc/sudoers
      ansible.builtin.lineinfile:
        path: /etc/sudoers
        regexp: ^[\s]*Defaults.*\buse_pty\b.*$
        line: Defaults use_pty
        validate: /usr/sbin/visudo -cf %s
      when:
      - '"kernel" in ansible_facts.packages'
      - '"sudo" in ansible_facts.packages'
      tags:
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sudo_add_use_pty
#### Rule Ensure Sudo Logfile Exists - sudo logfile [ref]
A custom log sudo file can be configured with the 'logfile' tag. This rule configures a sudo custom logfile at the default location suggested by CIS, which uses /var/log/sudo.log.
Rationale: | A sudo log file simplifies auditing of sudo commands.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_sudo_custom_logfile
References: |
pcidss | Req-10.2.5
cis | 4.3.3
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q sudo; }; then

    var_sudo_logfile='/var/log/sudo.log'

    if /usr/sbin/visudo -qcf /etc/sudoers; then
        cp /etc/sudoers /etc/sudoers.bak
        if ! grep -P '^[\s]*Defaults\b[^!\n]*\blogfile\s*=\s*(?:"?([^",\s]+)"?).*$' /etc/sudoers; then
            # sudoers file doesn't define Option logfile
            echo "Defaults logfile=${var_sudo_logfile}" >> /etc/sudoers
        else
            # sudoers file defines Option logfile, remediate if appropriate value is not set
            if ! grep -P "^[\s]*Defaults.*\blogfile=${var_sudo_logfile}\b.*$" /etc/sudoers; then

                escaped_variable=${var_sudo_logfile//$'/'/$'\/'}
                sed -Ei "s/(^[\s]*Defaults.*\blogfile=)[-]?.+(\b.*$)/\1$escaped_variable\2/" /etc/sudoers
            fi
        fi

        # Check validity of sudoers and cleanup bak
        if /usr/sbin/visudo -qcf /etc/sudoers; then
            rm -f /etc/sudoers.bak
        else
            echo "Fail to validate remediated /etc/sudoers, reverting to original file."
            mv /etc/sudoers.bak /etc/sudoers
            false
        fi
    else
        echo "Skipping remediation, /etc/sudoers failed to validate"
        false
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - restrict_strategy
      - sudo_custom_logfile
    - name: XCCDF Value var_sudo_logfile # promote to variable
      set_fact:
        var_sudo_logfile: !!str /var/log/sudo.log
      tags:
        - always

    - name: Ensure logfile is enabled with the appropriate value in /etc/sudoers
      ansible.builtin.lineinfile:
        path: /etc/sudoers
        regexp: ^[\s]*Defaults\s(.*)\blogfile=[-]?.+\b(.*)$
        line: Defaults \1logfile={{ var_sudo_logfile }}\2
        validate: /usr/sbin/visudo -cf %s
        backrefs: true
      register: edit_sudoers_logfile_option
      when:
      - '"kernel" in ansible_facts.packages'
      - '"sudo" in ansible_facts.packages'
      tags:
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - restrict_strategy
      - sudo_custom_logfile

    - name: Enable logfile option with appropriate value in /etc/sudoers
      ansible.builtin.lineinfile:
        path: /etc/sudoers
        line: Defaults logfile={{ var_sudo_logfile }}
        validate: /usr/sbin/visudo -cf %s
      when:
      - '"kernel" in ansible_facts.packages'
      - '"sudo" in ansible_facts.packages'
      - edit_sudoers_logfile_option is defined and not edit_sudoers_logfile_option.changed
      tags:
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - restrict_strategy
      - sudo_custom_logfile
#### Rule Require Re-Authentication When Using the sudo Command [ref]
The sudo `timestamp_timeout` tag sets the amount of time sudo password prompt waits. The default `timestamp_timeout` value is 5 minutes. The timestamp_timeout should be configured by making sure that the `timestamp_timeout` tag exists in `/etc/sudoers` configuration file or any sudo configuration snippets in `/etc/sudoers.d/`. If the value is set to an integer less than 0, the user's time stamp will not expire and the user will not have to re-authenticate for privileged actions until the user's session is terminated.
Rationale: | Without re-authentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical that the user re-authenticate.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sudo_require_reauthentication
References: |
nist | IA-11
os-srg | SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158
cis | 4.3.4, 4.3.5
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q sudo; }; then

    var_sudo_timestamp_timeout='5'

    if grep -Px '^[\s]*Defaults.*timestamp_timeout[\s]*=.*' /etc/sudoers.d/*; then
        find /etc/sudoers.d/ -type f -exec sed -Ei "/^[[:blank:]]*Defaults.*timestamp_timeout[[:blank:]]*=.*/d" {} \;
    fi

    if /usr/sbin/visudo -qcf /etc/sudoers; then
        cp /etc/sudoers /etc/sudoers.bak
        if ! grep -P '^[\s]*Defaults.*timestamp_timeout[\s]*=[\s]*[-]?\w+.*$' /etc/sudoers; then
            # sudoers file doesn't define Option timestamp_timeout
            echo "Defaults timestamp_timeout=${var_sudo_timestamp_timeout}" >> /etc/sudoers
        else
            # sudoers file defines Option timestamp_timeout, remediate wrong values if present
            if grep -qP "^[\s]*Defaults\s.*\btimestamp_timeout[\s]*=[\s]*(?!${var_sudo_timestamp_timeout}\b)[-]?\w+\b.*$" /etc/sudoers; then
                sed -Ei "s/(^[[:blank:]]*Defaults.*timestamp_timeout[[:blank:]]*=)[[:blank:]]*[-]?\w+(.*$)/\1${var_sudo_timestamp_timeout}\2/" /etc/sudoers
            fi
        fi

        # Check validity of sudoers and cleanup bak
        if /usr/sbin/visudo -qcf /etc/sudoers; then
            rm -f /etc/sudoers.bak
        else
            echo "Fail to validate remediated /etc/sudoers, reverting to original file."
            mv /etc/sudoers.bak /etc/sudoers
            false
        fi
    else
        echo "Skipping remediation, /etc/sudoers failed to validate"
        false
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-IA-11
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sudo_require_reauthentication
    - name: XCCDF Value var_sudo_timestamp_timeout # promote to variable
      set_fact:
        var_sudo_timestamp_timeout: !!str 5
      tags:
        - always

    - name: Require Re-Authentication When Using the sudo Command - Find /etc/sudoers.d/*
        files containing 'Defaults timestamp_timeout'
      ansible.builtin.find:
        path: /etc/sudoers.d
        patterns: '*'
        contains: ^[\s]*Defaults\s.*\btimestamp_timeout[\s]*=.*
      register: sudoers_d_defaults_timestamp_timeout
      when:
      - '"kernel" in ansible_facts.packages'
      - '"sudo" in ansible_facts.packages'
      tags:
      - NIST-800-53-IA-11
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sudo_require_reauthentication

    - name: Require Re-Authentication When Using the sudo Command - Remove 'Defaults timestamp_timeout'
        from /etc/sudoers.d/* files
      ansible.builtin.lineinfile:
        path: '{{ item.path }}'
        regexp: ^[\s]*Defaults\s.*\btimestamp_timeout[\s]*=.*
        state: absent
      with_items: '{{ sudoers_d_defaults_timestamp_timeout.files }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"sudo" in ansible_facts.packages'
      tags:
      - NIST-800-53-IA-11
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sudo_require_reauthentication

    - name: Require Re-Authentication When Using the sudo Command - Ensure timestamp_timeout
        has the appropriate value in /etc/sudoers
      ansible.builtin.lineinfile:
        path: /etc/sudoers
        regexp: ^[\s]*Defaults\s(.*)\btimestamp_timeout[\s]*=[\s]*[-]?\w+\b(.*)$
        line: Defaults \1timestamp_timeout={{ var_sudo_timestamp_timeout }}\2
        validate: /usr/sbin/visudo -cf %s
        backrefs: true
      register: edit_sudoers_timestamp_timeout_option
      when:
      - '"kernel" in ansible_facts.packages'
      - '"sudo" in ansible_facts.packages'
      tags:
      - NIST-800-53-IA-11
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sudo_require_reauthentication

    - name: Require Re-Authentication When Using the sudo Command - Enable timestamp_timeout
        option with correct value in /etc/sudoers
      ansible.builtin.lineinfile:
        path: /etc/sudoers
        line: Defaults timestamp_timeout={{ var_sudo_timestamp_timeout }}
        validate: /usr/sbin/visudo -cf %s
      when:
      - '"kernel" in ansible_facts.packages'
      - '"sudo" in ansible_facts.packages'
      - |
        edit_sudoers_timestamp_timeout_option is defined and not edit_sudoers_timestamp_timeout_option.changed
      tags:
      - NIST-800-53-IA-11
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sudo_require_reauthentication

    - name: Require Re-Authentication When Using the sudo Command - Remove timestamp_timeout
        wrong values in /etc/sudoers
      ansible.builtin.lineinfile:
        path: /etc/sudoers
        regexp: ^[\s]*Defaults\s.*\btimestamp_timeout[\s]*=[\s]*(?!{{ var_sudo_timestamp_timeout
          }}\b)[-]?\w+\b.*$
        state: absent
        validate: /usr/sbin/visudo -cf %s
      when:
      - '"kernel" in ansible_facts.packages'
      - '"sudo" in ansible_facts.packages'
      tags:
      - NIST-800-53-IA-11
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sudo_require_reauthentication
Group Updating Software Group contains 1 rule
[ref] The `dnf` command line tool is used to install and update software packages. The system also provides a graphical software update tool in the System menu, in the Administration submenu, called Software Update. Amazon Linux 2023 systems contain an installed software catalog called the RPM database, which records metadata of installed packages. Consistently using `dnf` or the graphical Software Update for all software installation allows for insight into the current inventory of installed software on the system.
#### Rule Ensure gpgcheck Enabled In Main dnf Configuration [ref]
The `gpgcheck` option controls whether RPM packages' signatures are always checked prior to installation. To configure dnf to check package signatures before installing them, ensure the following line appears in `/etc/dnf/dnf.conf` in the `[main]` section:
    gpgcheck=1
Rationale: | Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Accordingly, patches, service packs, device drivers, or operating system components must be signed with a certificate recognized and approved by the organization. Verifying the authenticity of the software prior to installation validates the integrity of the patch or upgrade received from a vendor. This ensures the software has not been tampered with and that it has been provided by a trusted vendor. Self-signed certificates are disallowed by this requirement. Certificates used to verify the software must be from an approved Certificate Authority (CA).
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_ensure_gpgcheck_globally_activated
References: |
cis-csc | 11, 2, 3, 9
cjis | 5.10.4.1
cobit5 | APO01.06, BAI03.05, BAI06.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS06.02
cui | 3.4.8
hipaa | 164.308(a)(1)(ii)(D), 164.312(b), 164.312(c)(1), 164.312(c)(2), 164.312(e)(2)(i)
isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.4
isa-62443-2013 | SR 3.1, SR 3.3, SR 3.4, SR 3.8, SR 7.6
iso27001-2013 | A.11.2.4, A.12.1.2, A.12.2.1, A.12.5.1, A.12.6.2, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4
nist | CM-5(3), SI-7, SC-12, SC-12(3), CM-6(a), SA-12, SA-12(10), CM-11(a), CM-11(b)
nist-csf | PR.DS-6, PR.DS-8, PR.IP-1
ospp | FPT_TUD_EXT.1, FPT_TUD_EXT.2
pcidss | Req-6.2
os-srg | SRG-OS-000366-GPOS-00153
anssi | R59
cis | 1.2.2
ism | 1493
pcidss4 | 6.3.3, 6.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q dnf; then

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^gpgcheck")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "1"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^gpgcheck\\>" "/etc/dnf/dnf.conf"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^gpgcheck\\>.*/$escaped_formatted_output/gi" "/etc/dnf/dnf.conf"
    else
        if [[ -s "/etc/dnf/dnf.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/dnf/dnf.conf" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/dnf/dnf.conf"
        fi
        printf '%s\n' "$formatted_output" >> "/etc/dnf/dnf.conf"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.4.1
      - NIST-800-171-3.4.8
      - NIST-800-53-CM-11(a)
      - NIST-800-53-CM-11(b)
      - NIST-800-53-CM-5(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SA-12
      - NIST-800-53-SA-12(10)
      - NIST-800-53-SC-12
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SI-7
      - PCI-DSS-Req-6.2
      - PCI-DSSv4-6.3
      - PCI-DSSv4-6.3.3
      - configure_strategy
      - ensure_gpgcheck_globally_activated
      - high_severity
      - low_complexity
      - medium_disruption
      - no_reboot_needed

    - name: Ensure GPG check is globally activated
      community.general.ini_file:
        dest: /etc/dnf/dnf.conf
        section: main
        option: gpgcheck
        value: 1
        no_extra_spaces: true
        create: false
      when: '"dnf" in ansible_facts.packages'
      tags:
      - CJIS-5.10.4.1
      - NIST-800-171-3.4.8
      - NIST-800-53-CM-11(a)
      - NIST-800-53-CM-11(b)
      - NIST-800-53-CM-5(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SA-12
      - NIST-800-53-SA-12(10)
      - NIST-800-53-SC-12
      - NIST-800-53-SC-12(3)
      - NIST-800-53-SI-7
      - PCI-DSS-Req-6.2
      - PCI-DSSv4-6.3
      - PCI-DSSv4-6.3.3
      - configure_strategy
      - ensure_gpgcheck_globally_activated
      - high_severity
      - low_complexity
      - medium_disruption
      - no_reboot_needed
Group Account and Access Control Group contains 14 groups and 62 rules
[ref] In traditional Unix security, if an attacker gains shell access to a certain login account, they can perform any action or access any file to which that account has access. Therefore, making it more difficult for unauthorized people to gain shell access to accounts, particularly to privileged accounts, is a necessary part of securing a system. This section introduces mechanisms for restricting access to accounts under Amazon Linux 2023.
Group Warning Banners for System Accesses Group contains 12 rules
[ref] Each system should expose as little information about itself as possible. System banners, which are typically displayed just before a login prompt, give out information about the service or the host's operating system. This might include the distribution name and the system kernel version, and the particular version of a network service. This information can assist intruders in gaining access to the system as it can reveal whether the system is running vulnerable software. Most network services can be configured to limit what information is displayed. Many organizations implement security policies that require a system banner provide notice of the system's ownership, provide warning to unauthorized users, and remind authorized users of their consent to monitoring.
#### Rule Modify the System Login Banner [ref]
To configure the system login banner edit `/etc/issue`. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either: `You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.` OR: `I've read & consent to terms in IS user agreem't.`
Rationale: | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_banner_etc_issue
References: |
cis-csc | 1, 12, 15, 16
cobit5 | DSS05.04, DSS05.10, DSS06.10
cui | 3.1.9
isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9
iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3
nist | AC-8(a), AC-8(c)
nist-csf | PR.AC-7
os-srg | SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
cis | 1.7.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    read -r -d '' login_banner_text <<'EOF' || true
    ^(Authorized[\s\n]+users[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$
    EOF

    # Multiple regexes transform the banner regex into a usable banner
    # 0 - Remove anchors around the banner text
    login_banner_text=$(echo "$login_banner_text" | sed 's/^\^\(.*\)\$$/\1/g')
    # 1 - Keep only the first banners if there are multiple
    #    (dod_banners contains the long and short banner)
    login_banner_text=$(echo "$login_banner_text" | sed 's/^(\(.*\.\)|.*)$/\1/g')
    # 2 - Add spaces ' '. (Transforms regex for "space or newline" into a " ")
    login_banner_text=$(echo "$login_banner_text" | sed 's/\[\\s\\n\]+/ /g')
    # 3 - Adds newlines. (Transforms "(?:\[\\n\]+|(?:\\n)+)" into "\n")
    login_banner_text=$(echo "$login_banner_text" | sed 's/(?:\[\\n\]+|(?:\\\\n)+)/\n/g')
    # 4 - Remove any leftover backslash. (From any parenthesis in the banner, for example).
    login_banner_text=$(echo "$login_banner_text" | sed 's/\\//g')
    formatted=$(echo "$login_banner_text" | fold -sw 80)
    cat <<EOF >/etc/issue
    $formatted
    EOF

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | unknown
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.9
      - NIST-800-53-AC-8(a)
      - NIST-800-53-AC-8(c)
      - banner_etc_issue
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - unknown_strategy
    - name: XCCDF Value login_banner_text # promote to variable
      set_fact:
        login_banner_text: !!str ^(Authorized[\s\n]+users[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$
      tags:
        - always

    - name: Modify the System Login Banner - Ensure Correct Banner
      ansible.builtin.copy:
        dest: /etc/issue
        content: '{{ login_banner_text | regex_replace("^\^(.*)\$$", "\1") | regex_replace("^\((.*\.)\|.*\)$",
          "\1") | regex_replace("\[\\s\\n\]\+"," ") | regex_replace("\(\?:\[\\n\]\+\|\(\?:\\\\n\)\+\)",
          "\n") | regex_replace("\\", "") | wordwrap() }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.9
      - NIST-800-53-AC-8(a)
      - NIST-800-53-AC-8(c)
      - banner_etc_issue
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - unknown_strategy
#### Rule Modify the System Login Banner for Remote Connections [ref]
To configure the system login banner edit `/etc/issue.net`. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either: `You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.` OR: `I've read & consent to terms in IS user agreem't.`
Rationale: | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_banner_etc_issue_net
References: |
os-srg | SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
cis | 1.7.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    remote_login_banner_text='^(Authorized[\s\n]+uses[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$'

    # Multiple regexes transform the banner regex into a usable banner
    # 0 - Remove anchors around the banner text
    remote_login_banner_text=$(echo "$remote_login_banner_text" | sed 's/^\^\(.*\)\$$/\1/g')
    # 1 - Keep only the first banners if there are multiple
    #    (dod_banners contains the long and short banner)
    remote_login_banner_text=$(echo "$remote_login_banner_text" | sed 's/^(\(.*\.\)|.*)$/\1/g')
    # 2 - Add spaces ' '. (Transforms regex for "space or newline" into a " ")
    remote_login_banner_text=$(echo "$remote_login_banner_text" | sed 's/\[\\s\\n\]+/ /g')
    # 3 - Adds newlines. (Transforms "(?:\[\\n\]+|(?:\\n)+)" into "\n")
    remote_login_banner_text=$(echo "$remote_login_banner_text" | sed 's/(?:\[\\n\]+|(?:\\\\n)+)/\n/g')
    # 4 - Remove any leftover backslash. (From any parenthesis in the banner, for example).
    remote_login_banner_text=$(echo "$remote_login_banner_text" | sed 's/\\//g')
    formatted=$(echo "$remote_login_banner_text" | fold -sw 80)

    cat <<EOF >/etc/issue.net
    $formatted
    EOF

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | unknown
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - banner_etc_issue_net
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - unknown_strategy
    - name: XCCDF Value remote_login_banner_text # promote to variable
      set_fact:
        remote_login_banner_text: !!str ^(Authorized[\s\n]+uses[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$
      tags:
        - always

    - name: Modify the System Login Banner for Remote Connections - ensure correct banner
      ansible.builtin.copy:
        dest: /etc/issue.net
        content: '{{ remote_login_banner_text | regex_replace("^\^(.*)\$$", "\1") | regex_replace("^\((.*\.)\|.*\)$",
          "\1") | regex_replace("\[\\s\\n\]\+"," ") | regex_replace("\(\?:\[\\n\]\+\|\(\?:\\\\n\)\+\)",
          "\n") | regex_replace("\\", "") | wordwrap() }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - banner_etc_issue_net
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - unknown_strategy
#### Rule Modify the System Message of the Day Banner [ref]
To configure the system message banner edit `/etc/motd`. Replace the default text with a message compliant with the local site policy or a legal disclaimer. The DoD required text is either: `You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details.` OR: `I've read & consent to terms in IS user agreem't.`
Rationale: | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_banner_etc_motd
References: |
cis | 1.7.1
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    motd_banner_text='^(Authorized[\s\n]+uses[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$'

    # Multiple regexes transform the banner regex into a usable banner
    # 0 - Remove anchors around the banner text
    motd_banner_text=$(echo "$motd_banner_text" | sed 's/^\^\(.*\)\$$/\1/g')
    # 1 - Keep only the first banners if there are multiple
    #    (dod_banners contains the long and short banner)
    motd_banner_text=$(echo "$motd_banner_text" | sed 's/^(\(.*\.\)|.*)$/\1/g')
    # 2 - Add spaces ' '. (Transforms regex for "space or newline" into a " ")
    motd_banner_text=$(echo "$motd_banner_text" | sed 's/\[\\s\\n\]+/ /g')
    # 3 - Adds newlines. (Transforms "(?:\[\\n\]+|(?:\\n)+)" into "\n")
    motd_banner_text=$(echo "$motd_banner_text" | sed 's/(?:\[\\n\]+|(?:\\\\n)+)/\n/g')
    # 4 - Remove any leftover backslash. (From any parenthesis in the banner, for example).
    motd_banner_text=$(echo "$motd_banner_text" | sed 's/\\//g')
    formatted=$(echo "$motd_banner_text" | fold -sw 80)

    cat <<EOF >/etc/motd
    $formatted
    EOF

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | unknown
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - banner_etc_motd
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - unknown_strategy
    - name: XCCDF Value motd_banner_text # promote to variable
      set_fact:
        motd_banner_text: !!str ^(Authorized[\s\n]+uses[\s\n]+only\.[\s\n]+All[\s\n]+activity[\s\n]+may[\s\n]+be[\s\n]+monitored[\s\n]+and[\s\n]+reported\.|^(?!.*(\\|fedora|rhel|sle|ubuntu)).*)$
      tags:
        - always

    - name: Modify the System Message of the Day Banner - ensure correct banner
      ansible.builtin.copy:
        dest: /etc/motd
        content: '{{ motd_banner_text | regex_replace("^\^(.*)\$$", "\1") | regex_replace("^\((.*\.)\|.*\)$",
          "\1") | regex_replace("\[\\s\\n\]\+"," ") | regex_replace("\(\?:\[\\n\]\+\|\(\?:\\\\n\)\+\)",
          "\n") | regex_replace("\\", "") | wordwrap() }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - banner_etc_motd
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - unknown_strategy
#### Rule Verify Group Ownership of System Login Banner [ref]
To properly set the group owner of `/etc/issue`, run the command:
    $ sudo chgrp root /etc/issue
Rationale: | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. Proper group ownership will ensure that only root user can modify the banner.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_etc_issue
References: |
cis | 1.7.5
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/issue" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/issue
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_groupowner_etc_issue_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_etc_issue_newgroup: '0'
      tags:
      - configure_strategy
      - file_groupowner_etc_issue
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/issue
      ansible.builtin.stat:
        path: /etc/issue
      register: file_exists
      tags:
      - configure_strategy
      - file_groupowner_etc_issue
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/issue
      ansible.builtin.file:
        path: /etc/issue
        follow: false
        group: '{{ file_groupowner_etc_issue_newgroup }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_groupowner_etc_issue
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Ownership of System Login Banner for Remote Connections [ref]
To properly set the group owner of `/etc/issue.net`, run the command:
    $ sudo chgrp root /etc/issue.net
Rationale: | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. Proper group ownership will ensure that only root user can modify the banner.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_etc_issue_net
References: |
cis | 1.7.6
pcidss4 | 1.2.8, 1.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/issue.net" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/issue.net
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_groupowner_etc_issue_net_newgroup variable if represented by
        gid
      ansible.builtin.set_fact:
        file_groupowner_etc_issue_net_newgroup: '0'
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.8
      - configure_strategy
      - file_groupowner_etc_issue_net
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/issue.net
      ansible.builtin.stat:
        path: /etc/issue.net
      register: file_exists
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.8
      - configure_strategy
      - file_groupowner_etc_issue_net
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/issue.net
      ansible.builtin.file:
        path: /etc/issue.net
        follow: false
        group: '{{ file_groupowner_etc_issue_net_newgroup }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.8
      - configure_strategy
      - file_groupowner_etc_issue_net
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Ownership of Message of the Day Banner [ref]
To properly set the group owner of `/etc/motd`, run the command:
    $ sudo chgrp root /etc/motd
Rationale: | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. Proper group ownership will ensure that only root user can modify the banner.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_etc_motd
References: |
cis | 1.7.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/motd" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/motd
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_groupowner_etc_motd_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_etc_motd_newgroup: '0'
      tags:
      - configure_strategy
      - file_groupowner_etc_motd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/motd
      ansible.builtin.stat:
        path: /etc/motd
      register: file_exists
      tags:
      - configure_strategy
      - file_groupowner_etc_motd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/motd
      ansible.builtin.file:
        path: /etc/motd
        follow: false
        group: '{{ file_groupowner_etc_motd_newgroup }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_groupowner_etc_motd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify ownership of System Login Banner [ref]
To properly set the owner of `/etc/issue`, run the command:
    $ sudo chown root /etc/issue
Rationale: | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. Proper ownership will ensure that only root user can modify the banner.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_etc_issue
References: |
cis | 1.7.5
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/issue" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/issue
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_owner_etc_issue_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_etc_issue_newown: '0'
      tags:
      - configure_strategy
      - file_owner_etc_issue
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/issue
      ansible.builtin.stat:
        path: /etc/issue
      register: file_exists
      tags:
      - configure_strategy
      - file_owner_etc_issue
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/issue
      ansible.builtin.file:
        path: /etc/issue
        follow: false
        owner: '{{ file_owner_etc_issue_newown }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_owner_etc_issue
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify ownership of System Login Banner for Remote Connections [ref]
To properly set the owner of `/etc/issue.net`, run the command:
    $ sudo chown root /etc/issue.net
Rationale: | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. Proper ownership will ensure that only root user can modify the banner.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_etc_issue_net
References: |
cis | 1.7.6
pcidss4 | 1.2.8, 1.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/issue.net" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/issue.net
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_owner_etc_issue_net_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_etc_issue_net_newown: '0'
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.8
      - configure_strategy
      - file_owner_etc_issue_net
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/issue.net
      ansible.builtin.stat:
        path: /etc/issue.net
      register: file_exists
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.8
      - configure_strategy
      - file_owner_etc_issue_net
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/issue.net
      ansible.builtin.file:
        path: /etc/issue.net
        follow: false
        owner: '{{ file_owner_etc_issue_net_newown }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.8
      - configure_strategy
      - file_owner_etc_issue_net
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify ownership of Message of the Day Banner [ref]
To properly set the owner of `/etc/motd`, run the command:
    $ sudo chown root /etc/motd
Rationale: | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. Proper ownership will ensure that only root user can modify the banner.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_etc_motd
References: |
cis | 1.7.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/motd" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/motd
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_owner_etc_motd_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_etc_motd_newown: '0'
      tags:
      - configure_strategy
      - file_owner_etc_motd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/motd
      ansible.builtin.stat:
        path: /etc/motd
      register: file_exists
      tags:
      - configure_strategy
      - file_owner_etc_motd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/motd
      ansible.builtin.file:
        path: /etc/motd
        follow: false
        owner: '{{ file_owner_etc_motd_newown }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_owner_etc_motd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify permissions on System Login Banner [ref]
To properly set the permissions of `/etc/issue`, run the command:
    $ sudo chmod 0644 /etc/issue
Rationale: | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. Proper permissions will ensure that only root user can modify the banner.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_etc_issue
References: |
cis | 1.7.5
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    chmod u-xs,g-xws,o-xwt /etc/issue
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Test for existence /etc/issue
      ansible.builtin.stat:
        path: /etc/issue
      register: file_exists
      tags:
      - configure_strategy
      - file_permissions_etc_issue
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xws,o-xwt on /etc/issue
      ansible.builtin.file:
        path: /etc/issue
        mode: u-xs,g-xws,o-xwt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_permissions_etc_issue
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify permissions on System Login Banner for Remote Connections [ref]
To properly set the permissions of `/etc/issue.net`, run the command:
    $ sudo chmod 0644 /etc/issue.net
Rationale: | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. Proper permissions will ensure that only root user can modify the banner.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_etc_issue_net
References: |
cis | 1.7.6
pcidss4 | 1.2.8, 1.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    chmod u-xs,g-xws,o-xwt /etc/issue.net
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Test for existence /etc/issue.net
      ansible.builtin.stat:
        path: /etc/issue.net
      register: file_exists
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.8
      - configure_strategy
      - file_permissions_etc_issue_net
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xws,o-xwt on /etc/issue.net
      ansible.builtin.file:
        path: /etc/issue.net
        mode: u-xs,g-xws,o-xwt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.8
      - configure_strategy
      - file_permissions_etc_issue_net
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify permissions on Message of the Day Banner [ref]
To properly set the permissions of `/etc/motd`, run the command:
    $ sudo chmod 0644 /etc/motd
Rationale: | Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. Proper permissions will ensure that only root user can modify the banner.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_etc_motd
References: |
cis | 1.7.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    chmod u-xs,g-xws,o-xwt /etc/motd
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Test for existence /etc/motd
      ansible.builtin.stat:
        path: /etc/motd
      register: file_exists
      tags:
      - configure_strategy
      - file_permissions_etc_motd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xws,o-xwt on /etc/motd
      ansible.builtin.file:
        path: /etc/motd
        mode: u-xs,g-xws,o-xwt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_permissions_etc_motd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
Group Protect Accounts by Configuring PAM Group contains 4 groups and 12 rules
[ref] PAM, or Pluggable Authentication Modules, is a system which implements modular authentication for Linux programs. PAM provides a flexible and configurable architecture for authentication, and it should be configured to minimize exposure to unnecessary risk. This section contains guidance on how to accomplish that. PAM is implemented as a set of shared objects which are loaded and invoked whenever an application wishes to authenticate a user. Typically, the application must be running as root in order to take advantage of PAM, because PAM's modules often need to be able to access sensitive stores of account information, such as /etc/shadow. Traditional privileged network listeners (e.g. sshd) or SUID programs (e.g. sudo) already meet this requirement. An SUID root application, userhelper, is provided so that programs which are not SUID or privileged themselves can still take advantage of PAM. PAM looks in the directory `/etc/pam.d` for application-specific configuration information. For instance, if the program login attempts to authenticate a user, then PAM's libraries follow the instructions in the file `/etc/pam.d/login` to determine what actions should be taken. One very important file in `/etc/pam.d` is `/etc/pam.d/system-auth`. This file, which is included by many other PAM configuration files, defines 'default' system authentication measures. Modifying this file is a good way to make far-reaching authentication changes, for instance when implementing a centralized authentication service. Warning: Be careful when making changes to PAM's configuration files. The syntax for these files is complex, and modifications can have unexpected consequences. The default configurations shipped with applications should be sufficient for most users. Warning: Running `authconfig` or `system-config-authentication` will re-write the PAM configuration files, destroying any manually made changes and replacing them with a series of system defaults. One reference to the configuration file syntax can be found at https://fossies.org/linux/Linux-PAM-docs/doc/sag/Linux-PAM_SAG.pdf.
Group Set Lockouts for Failed Password Attempts Group contains 6 rules
[ref] The `pam_faillock` PAM module provides the capability to lock out user accounts after a number of failed login attempts. Its documentation is available in `/usr/share/doc/pam-VERSION/txts/README.pam_faillock`. Warning: Locking out user accounts presents the risk of a denial-of-service attack. The lockout policy must weigh whether the risk of such a denial-of-service attack outweighs the benefits of thwarting password guessing attacks.
#### Rule Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth File. [ref]
The pam_faillock.so module must be loaded in preauth in /etc/pam.d/password-auth.
Rationale: | If the pam_faillock.so module is not loaded the system will not correctly lockout accounts to prevent password guessing attacks.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_account_password_pam_faillock_password_auth
References: |
nist | AC-7 (a)
os-srg | SRG-OS-000021-GPOS-00005
cis | 4.4.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    authselect select "$(authselect current --raw)" --force
    if [ -f /usr/bin/authselect ]; then
        if ! authselect check; then
    echo "
    authselect integrity check failed. Remediation aborted!
    This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
    It is not recommended to manually edit the PAM files when authselect tool is available.
    In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
    exit 1
    fi
    authselect enable-feature with-faillock

    authselect apply-changes -b
    else

    AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
    for pam_file in "${AUTH_FILES[@]}"
    do
        if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+(preauth silent|authfail).*$' "$pam_file" ; then
            sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix\.so.*/i auth        required      pam_faillock.so preauth silent' "$pam_file"
            sed -i --follow-symlinks '/^auth.*required.*pam_deny\.so.*/i auth        required      pam_faillock.so authfail' "$pam_file"
            sed -i --follow-symlinks '/^account.*required.*pam_unix\.so.*/i account     required      pam_faillock.so' "$pam_file"
        fi
        sed -Ei 's/(auth.*)(\[default=die\])(.*pam_faillock\.so)/\1required     \3/g' "$pam_file"
    done

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-7 (a)
      - account_password_pam_faillock_password_auth
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
        File. - Force reselect authselect profile
      ansible.builtin.shell:
        cmd: authselect select "$(authselect current --raw)" --force
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-7 (a)
      - account_password_pam_faillock_password_auth
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
        File. - Check if system relies on authselect tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-7 (a)
      - account_password_pam_faillock_password_auth
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
        File. - Remediation where authselect tool is present
      block:

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
          File. - Check integrity of authselect current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        check_mode: false
        failed_when: false

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
          File. - Informative message based on the authselect integrity check result
        ansible.builtin.assert:
          that:
          - ansible_check_mode or result_authselect_check_cmd.rc == 0
          fail_msg:
          - authselect integrity check failed. Remediation aborted!
          - This remediation could not be applied because an authselect profile was not
            selected or the selected profile is not intact.
          - It is not recommended to manually edit the PAM files when authselect tool
            is available.
          - In cases where the default authselect profile does not cover a specific demand,
            a custom authselect profile is recommended.
          success_msg:
          - authselect integrity check passed

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
          File. - Get authselect current features
        ansible.builtin.shell:
          cmd: authselect current | tail -n+3 | awk '{ print $2 }'
        register: result_authselect_features
        changed_when: false
        check_mode: false
        when:
        - result_authselect_check_cmd is success

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
          File. - Ensure "with-faillock" feature is enabled using authselect tool
        ansible.builtin.command:
          cmd: authselect enable-feature with-faillock
        register: result_authselect_enable_feature_cmd
        when:
        - result_authselect_check_cmd is success
        - result_authselect_features.stdout is not search("with-faillock")

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
          File. - Ensure authselect changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_enable_feature_cmd is not skipped
        - result_authselect_enable_feature_cmd is success
      when:
      - '"kernel" in ansible_facts.packages'
      - result_authselect_present.stat.exists
      tags:
      - NIST-800-53-AC-7 (a)
      - account_password_pam_faillock_password_auth
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
        File. - Remediation where authselect tool is not present
      block:

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
          File. - Check if pam_faillock.so is already enabled
        ansible.builtin.lineinfile:
          path: /etc/pam.d/system-auth
          regexp: .*auth.*pam_faillock\.so (preauth|authfail)
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_faillock_is_enabled

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
          File. - Enable pam_faillock.so preauth editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: auth        required      pam_faillock.so preauth
          insertbefore: ^auth.*sufficient.*pam_unix\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
          File. - Enable pam_faillock.so authfail editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: auth        required      pam_faillock.so authfail
          insertbefore: ^auth.*required.*pam_deny\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/password-auth
          File. - Enable pam_faillock.so account section editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: account     required      pam_faillock.so
          insertbefore: ^account.*required.*pam_unix\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0
      when:
      - '"kernel" in ansible_facts.packages'
      - not result_authselect_present.stat.exists
      tags:
      - NIST-800-53-AC-7 (a)
      - account_password_pam_faillock_password_auth
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth File. [ref]
The pam_faillock.so module must be loaded in preauth in /etc/pam.d/system-auth.
Rationale: | If the pam_faillock.so module is not loaded the system will not correctly lockout accounts to prevent password guessing attacks.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_account_password_pam_faillock_system_auth
References: |
nist | AC-7 (a)
os-srg | SRG-OS-000021-GPOS-00005
cis | 4.4.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if [ -f /usr/bin/authselect ]; then
        if ! authselect check; then
    echo "
    authselect integrity check failed. Remediation aborted!
    This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
    It is not recommended to manually edit the PAM files when authselect tool is available.
    In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
    exit 1
    fi
    authselect enable-feature with-faillock

    authselect apply-changes -b
    else

    AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
    for pam_file in "${AUTH_FILES[@]}"
    do
        if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+(preauth silent|authfail).*$' "$pam_file" ; then
            sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix\.so.*/i auth        required      pam_faillock.so preauth silent' "$pam_file"
            sed -i --follow-symlinks '/^auth.*required.*pam_deny\.so.*/i auth        required      pam_faillock.so authfail' "$pam_file"
            sed -i --follow-symlinks '/^account.*required.*pam_unix\.so.*/i account     required      pam_faillock.so' "$pam_file"
        fi
        sed -Ei 's/(auth.*)(\[default=die\])(.*pam_faillock\.so)/\1required     \3/g' "$pam_file"
    done

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-7 (a)
      - account_password_pam_faillock_system_auth
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth
        File. - Check if system relies on authselect tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-7 (a)
      - account_password_pam_faillock_system_auth
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth
        File. - Remediation where authselect tool is present
      block:

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth
          File. - Check integrity of authselect current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        check_mode: false
        failed_when: false

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth
          File. - Informative message based on the authselect integrity check result
        ansible.builtin.assert:
          that:
          - ansible_check_mode or result_authselect_check_cmd.rc == 0
          fail_msg:
          - authselect integrity check failed. Remediation aborted!
          - This remediation could not be applied because an authselect profile was not
            selected or the selected profile is not intact.
          - It is not recommended to manually edit the PAM files when authselect tool
            is available.
          - In cases where the default authselect profile does not cover a specific demand,
            a custom authselect profile is recommended.
          success_msg:
          - authselect integrity check passed

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth
          File. - Get authselect current features
        ansible.builtin.shell:
          cmd: authselect current | tail -n+3 | awk '{ print $2 }'
        register: result_authselect_features
        changed_when: false
        check_mode: false
        when:
        - result_authselect_check_cmd is success

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth
          File. - Ensure "with-faillock" feature is enabled using authselect tool
        ansible.builtin.command:
          cmd: authselect enable-feature with-faillock
        register: result_authselect_enable_feature_cmd
        when:
        - result_authselect_check_cmd is success
        - result_authselect_features.stdout is not search("with-faillock")

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth
          File. - Ensure authselect changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_enable_feature_cmd is not skipped
        - result_authselect_enable_feature_cmd is success
      when:
      - '"kernel" in ansible_facts.packages'
      - result_authselect_present.stat.exists
      tags:
      - NIST-800-53-AC-7 (a)
      - account_password_pam_faillock_system_auth
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth
        File. - Remediation where authselect tool is not present
      block:

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth
          File. - Check if pam_faillock.so is already enabled
        ansible.builtin.lineinfile:
          path: /etc/pam.d/system-auth
          regexp: .*auth.*pam_faillock\.so (preauth|authfail)
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_faillock_is_enabled

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth
          File. - Enable pam_faillock.so preauth editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: auth        required      pam_faillock.so preauth
          insertbefore: ^auth.*sufficient.*pam_unix\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth
          File. - Enable pam_faillock.so authfail editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: auth        required      pam_faillock.so authfail
          insertbefore: ^auth.*required.*pam_deny\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0

      - name: Configure the Use of the pam_faillock.so Module in the /etc/pam.d/system-auth
          File. - Enable pam_faillock.so account section editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: account     required      pam_faillock.so
          insertbefore: ^account.*required.*pam_unix\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0
      when:
      - '"kernel" in ansible_facts.packages'
      - not result_authselect_present.stat.exists
      tags:
      - NIST-800-53-AC-7 (a)
      - account_password_pam_faillock_system_auth
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Limit Password Reuse: password-auth [ref]
Do not allow users to reuse recent passwords. This can be accomplished by using the `remember` option for the `pam_pwhistory` PAM module. On systems with newer versions of `authselect`, the `pam_pwhistory` PAM module can be enabled via authselect feature:
    authselect enable-feature with-pwhistory
Otherwise, it should be enabled using an authselect custom profile. Newer systems also have the `/etc/security/pwhistory.conf` file for setting `pam_pwhistory` module options. This file should be used whenever available. Otherwise, the `pam_pwhistory` module options can be set in PAM files. The value for `remember` option must be equal or greater than 5 Warning: If the system relies on `authselect` tool to manage PAM settings, the remediation will also use `authselect` tool. However, if any manual modification was made in PAM files, the `authselect` integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. Warning: Newer versions of `authselect` contain an authselect feature to easily and properly enable `pam_pwhistory.so` module. If this feature is not yet available in your system, an authselect custom profile must be used to avoid integrity issues in PAM files. If a custom profile was created and used in the system before this authselect feature was available, the new feature can't be used with this custom profile and the remediation will fail. In this case, the custom profile should be recreated or manually updated.
Rationale: | Preventing reuse of previous passwords helps ensure that a compromised password is not reused by a user.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_pwhistory_remember_password_auth
References: |
cis-csc | 1, 12, 15, 16, 5
cjis | 5.6.2.1.1
cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.5.8
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1
iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nist | IA-5(f), IA-5(1)(e)
nist-csf | PR.AC-1, PR.AC-6, PR.AC-7
pcidss | Req-8.2.5
os-srg | SRG-OS-000077-GPOS-00045
cis | 4.5.3
pcidss4 | 8.3.7, 8.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q pam; }; then

    var_password_pam_remember='5'
    var_password_pam_remember_control_flag='requisite,required'

    var_password_pam_remember_control_flag="$(echo $var_password_pam_remember_control_flag | cut -d \, -f 1)"

    if [ -f /usr/bin/authselect ]; then
        if authselect list-features sssd | grep -q with-pwhistory; then
            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi
            authselect enable-feature with-pwhistory

            authselect apply-changes -b
        else

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                # The "local" profile does not contain essential security features required by multiple Benchmarks.
                # If currently used, it is replaced by "sssd", which is the best option in this case.
                if [[ $CURRENT_PROFILE == local ]]; then
                    CURRENT_PROFILE="sssd"
                fi
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "/etc/pam.d/password-auth")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b

            if ! grep -qP "^\s*password\s+\$var_password_pam_remember_control_flag\s+pam_pwhistory.so\s*.*" "$PAM_FILE_PATH"; then
                # Line matching group + control + module was not found. Check group + module.
                if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwhistory.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                    # The control is updated only if one single line matches.
                    sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_pwhistory.so.*)/\1$var_password_pam_remember_control_flag \2/" "$PAM_FILE_PATH"
                else
                    LAST_MATCH_LINE=$(grep -nP "^password.*requisite.*pam_pwquality\.so" "$PAM_FILE_PATH" | tail -n 1 | cut -d: -f 1)
                    if [ ! -z $LAST_MATCH_LINE ]; then
                        sed -i --follow-symlinks $LAST_MATCH_LINE" a password     $var_password_pam_remember_control_flag    pam_pwhistory.so" "$PAM_FILE_PATH"
                    else
                        echo "password    $var_password_pam_remember_control_flag    pam_pwhistory.so" >> "$PAM_FILE_PATH"
                    fi
                fi
            fi
        fi
    else

        if ! grep -qP "^\s*password\s+\$var_password_pam_remember_control_flag\s+pam_pwhistory.so\s*.*" "/etc/pam.d/password-auth"; then
            # Line matching group + control + module was not found. Check group + module.
            if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwhistory.so\s*' "/etc/pam.d/password-auth")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_pwhistory.so.*)/\1$var_password_pam_remember_control_flag \2/" "/etc/pam.d/password-auth"
            else
                LAST_MATCH_LINE=$(grep -nP "^password.*requisite.*pam_pwquality\.so" "/etc/pam.d/password-auth" | tail -n 1 | cut -d: -f 1)
                if [ ! -z $LAST_MATCH_LINE ]; then
                    sed -i --follow-symlinks $LAST_MATCH_LINE" a password     $var_password_pam_remember_control_flag    pam_pwhistory.so" "/etc/pam.d/password-auth"
                else
                    echo "password    $var_password_pam_remember_control_flag    pam_pwhistory.so" >> "/etc/pam.d/password-auth"
                fi
            fi
        fi

    fi

    PWHISTORY_CONF="/etc/security/pwhistory.conf"
    if [ -f $PWHISTORY_CONF ]; then
        regex="^\s*remember\s*="
        line="remember = $var_password_pam_remember"
        if ! grep -q $regex $PWHISTORY_CONF; then
            echo $line >> $PWHISTORY_CONF
        else
            sed -i --follow-symlinks 's|^\s*\(remember\s*=\s*\)\(\S\+\)|\1'"$var_password_pam_remember"'|g' $PWHISTORY_CONF
        fi
        if [ -e "/etc/pam.d/password-auth" ] ; then
            PAM_FILE_PATH="/etc/pam.d/password-auth"
            if [ -f /usr/bin/authselect ]; then

                if ! authselect check; then
                echo "
                authselect integrity check failed. Remediation aborted!
                This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
                It is not recommended to manually edit the PAM files when authselect tool is available.
                In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
                exit 1
                fi

                CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
                # If not already in use, a custom profile is created preserving the enabled features.
                if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                    ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                    # The "local" profile does not contain essential security features required by multiple Benchmarks.
                    # If currently used, it is replaced by "sssd", which is the best option in this case.
                    if [[ $CURRENT_PROFILE == local ]]; then
                        CURRENT_PROFILE="sssd"
                    fi
                    authselect create-profile hardening -b $CURRENT_PROFILE
                    CURRENT_PROFILE="custom/hardening"

                    authselect apply-changes -b --backup=before-hardening-custom-profile
                    authselect select $CURRENT_PROFILE
                    for feature in $ENABLED_FEATURES; do
                        authselect enable-feature $feature;
                    done

                    authselect apply-changes -b --backup=after-hardening-custom-profile
                fi
                PAM_FILE_NAME=$(basename "/etc/pam.d/password-auth")
                PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

                authselect apply-changes -b
            fi

        if grep -qP "^\s*password\s.*\bpam_pwhistory.so\s.*\bremember\b" "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks "s/(.*password.*pam_pwhistory.so.*)\bremember\b=?[[:alnum:]]*(.*)/\1\2/g" "$PAM_FILE_PATH"
        fi
            if [ -f /usr/bin/authselect ]; then

                authselect apply-changes -b
            fi
        else
            echo "/etc/pam.d/password-auth was not found" >&2
        fi
    else
        PAM_FILE_PATH="/etc/pam.d/password-auth"
        if [ -f /usr/bin/authselect ]; then

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                # The "local" profile does not contain essential security features required by multiple Benchmarks.
                # If currently used, it is replaced by "sssd", which is the best option in this case.
                if [[ $CURRENT_PROFILE == local ]]; then
                    CURRENT_PROFILE="sssd"
                fi
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "/etc/pam.d/password-auth")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
        fi

        if ! grep -qP "^\s*password\s+requisite\s+pam_pwhistory.so\s*.*" "$PAM_FILE_PATH"; then
            # Line matching group + control + module was not found. Check group + module.
            if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwhistory.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_pwhistory.so.*)/\1requisite \2/" "$PAM_FILE_PATH"
            else
                echo "password    requisite    pam_pwhistory.so" >> "$PAM_FILE_PATH"
            fi
        fi
        # Check the option
        if ! grep -qP "^\s*password\s+requisite\s+pam_pwhistory.so\s*.*\sremember\b" "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks "/\s*password\s+requisite\s+pam_pwhistory.so.*/ s/$/ remember=$var_password_pam_remember/" "$PAM_FILE_PATH"
        else
            sed -i -E --follow-symlinks "s/(\s*password\s+requisite\s+pam_pwhistory.so\s+.*)(remember=)[[:alnum:]]*\s*(.*)/\1\2$var_password_pam_remember \3/" "$PAM_FILE_PATH"
        fi
        if [ -f /usr/bin/authselect ]; then

            authselect apply-changes -b
        fi
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_password_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
    - name: XCCDF Value var_password_pam_remember # promote to variable
      set_fact:
        var_password_pam_remember: !!str 5
      tags:
        - always
    - name: XCCDF Value var_password_pam_remember_control_flag # promote to variable
      set_fact:
        var_password_pam_remember_control_flag: !!str requisite,required
      tags:
        - always

    - name: 'Limit Password Reuse: password-auth - Check if system relies on authselect
        tool'
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_password_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: 'Limit Password Reuse: password-auth - Collect the available authselect features'
      ansible.builtin.command:
        cmd: authselect list-features sssd
      register: result_authselect_available_features
      changed_when: false
      check_mode: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_authselect_present.stat.exists
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_password_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: 'Limit Password Reuse: password-auth - Enable pam_pwhistory.so using authselect
        feature'
      block:

      - name: 'Limit Password Reuse: password-auth - Check integrity of authselect current
          profile'
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        check_mode: false
        failed_when: false

      - name: 'Limit Password Reuse: password-auth - Informative message based on the
          authselect integrity check result'
        ansible.builtin.assert:
          that:
          - ansible_check_mode or result_authselect_check_cmd.rc == 0
          fail_msg:
          - authselect integrity check failed. Remediation aborted!
          - This remediation could not be applied because an authselect profile was not
            selected or the selected profile is not intact.
          - It is not recommended to manually edit the PAM files when authselect tool
            is available.
          - In cases where the default authselect profile does not cover a specific demand,
            a custom authselect profile is recommended.
          success_msg:
          - authselect integrity check passed

      - name: 'Limit Password Reuse: password-auth - Get authselect current features'
        ansible.builtin.shell:
          cmd: authselect current | tail -n+3 | awk '{ print $2 }'
        register: result_authselect_features
        changed_when: false
        check_mode: false
        when:
        - result_authselect_check_cmd is success

      - name: 'Limit Password Reuse: password-auth - Ensure "with-pwhistory" feature is
          enabled using authselect tool'
        ansible.builtin.command:
          cmd: authselect enable-feature with-pwhistory
        register: result_authselect_enable_feature_cmd
        when:
        - result_authselect_check_cmd is success
        - result_authselect_features.stdout is not search("with-pwhistory")

      - name: 'Limit Password Reuse: password-auth - Ensure authselect changes are applied'
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_enable_feature_cmd is not skipped
        - result_authselect_enable_feature_cmd is success
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_authselect_present.stat.exists
      - result_authselect_available_features.stdout is search("with-pwhistory")
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_password_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: 'Limit Password Reuse: password-auth - Enable pam_pwhistory.so in appropriate
        PAM files'
      block:

      - name: 'Limit Password Reuse: password-auth - Define the PAM file to be edited
          as a local fact'
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/password-auth

      - name: 'Limit Password Reuse: password-auth - Check if system relies on authselect
          tool'
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: 'Limit Password Reuse: password-auth - Ensure authselect custom profile
          is used if authselect is present'
        block:

        - name: 'Limit Password Reuse: password-auth - Check integrity of authselect current
            profile'
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          check_mode: false
          failed_when: false

        - name: 'Limit Password Reuse: password-auth - Informative message based on the
            authselect integrity check result'
          ansible.builtin.assert:
            that:
            - ansible_check_mode or result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: 'Limit Password Reuse: password-auth - Get authselect current profile'
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: 'Limit Password Reuse: password-auth - Define the current authselect profile
            as a local fact'
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: 'Limit Password Reuse: password-auth - Define the new authselect custom
            profile as a local fact'
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: 'Limit Password Reuse: password-auth - Get authselect current features
            to also enable them in the custom profile'
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          check_mode: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: 'Limit Password Reuse: password-auth - Check if any custom profile with
            the same name was already created'
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: 'Limit Password Reuse: password-auth - Create an authselect custom profile
            based on the current profile'
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("^(custom/|local)")
          - not result_authselect_custom_profile_present.stat.exists

        - name: 'Limit Password Reuse: password-auth - Create an authselect custom profile
            based on sssd profile'
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b sssd
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is match("local")
          - not result_authselect_custom_profile_present.stat.exists

        - name: 'Limit Password Reuse: password-auth - Ensure authselect changes are applied'
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: 'Limit Password Reuse: password-auth - Ensure the authselect custom profile
            is selected'
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: 'Limit Password Reuse: password-auth - Restore the authselect features
            in the custom profile'
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: 'Limit Password Reuse: password-auth - Ensure authselect changes are applied'
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: 'Limit Password Reuse: password-auth - Change the PAM file to be edited
            according to the custom authselect profile'
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
          when:
          - authselect_custom_profile is defined
        when:
        - result_authselect_present.stat.exists

      - name: 'Limit Password Reuse: password-auth - Define a fact for control already
          filtered in case filters are used'
        ansible.builtin.set_fact:
          pam_module_control: '{{ var_password_pam_remember_control_flag.split(",")[0]
            }}'

      - name: 'Limit Password Reuse: password-auth - Check if expected PAM module line
          is present in {{ pam_file_path }}'
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so\s*.*
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_line_present

      - name: 'Limit Password Reuse: password-auth - Include or update the PAM module
          line in {{ pam_file_path }}'
        block:

        - name: 'Limit Password Reuse: password-auth - Check if required PAM module line
            is present in {{ pam_file_path }} with different control'
          ansible.builtin.lineinfile:
            path: '{{ pam_file_path }}'
            regexp: ^\s*password\s+.*\s+pam_pwhistory.so\s*
            state: absent
          check_mode: true
          changed_when: false
          register: result_pam_line_other_control_present

        - name: 'Limit Password Reuse: password-auth - Ensure the correct control for
            the required PAM module line in {{ pam_file_path }}'
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: ^(\s*password\s+).*(\bpam_pwhistory.so.*)
            replace: \1{{ pam_module_control }} \2
          register: result_pam_module_edit
          when:
          - result_pam_line_other_control_present.found == 1

        - name: 'Limit Password Reuse: password-auth - Ensure the required PAM module
            line is included in {{ pam_file_path }}'
          ansible.builtin.lineinfile:
            dest: '{{ pam_file_path }}'
            insertafter: ^password.*requisite.*pam_pwquality\.so
            line: password    {{ pam_module_control }}    pam_pwhistory.so
          register: result_pam_module_add
          when:
          - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
            > 1

        - name: 'Limit Password Reuse: password-auth - Ensure authselect changes are applied'
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present is defined
          - result_authselect_present.stat.exists
          - |-
            (result_pam_module_add is defined and result_pam_module_add.changed)
             or (result_pam_module_edit is defined and result_pam_module_edit.changed)
        when:
        - result_pam_line_present.found is defined
        - result_pam_line_present.found == 0
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - |
        (result_authselect_available_features.stdout is defined and result_authselect_available_features.stdout is not search("with-pwhistory")) or result_authselect_available_features is not defined
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_password_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: 'Limit Password Reuse: password-auth - Check the presence of /etc/security/pwhistory.conf
        file'
      ansible.builtin.stat:
        path: /etc/security/pwhistory.conf
      register: result_pwhistory_conf_check
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_password_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: 'Limit Password Reuse: password-auth - pam_pwhistory.so parameters are configured
        in /etc/security/pwhistory.conf file'
      block:

      - name: 'Limit Password Reuse: password-auth - Ensure the pam_pwhistory.so remember
          parameter in /etc/security/pwhistory.conf'
        ansible.builtin.lineinfile:
          path: /etc/security/pwhistory.conf
          regexp: ^\s*remember\s*=
          line: remember = {{ var_password_pam_remember }}
          state: present

      - name: 'Limit Password Reuse: password-auth - Ensure the pam_pwhistory.so remember
          parameter is removed from PAM files'
        block:

        - name: 'Limit Password Reuse: password-auth - Check if /etc/pam.d/password-auth
            file is present'
          ansible.builtin.stat:
            path: /etc/pam.d/password-auth
          register: result_pam_password_auth_file_present

        - name: 'Limit Password Reuse: password-auth - Check the proper remediation for
            the system'
          block:

          - name: 'Limit Password Reuse: password-auth - Define the PAM file to be edited
              as a local fact'
            ansible.builtin.set_fact:
              pam_file_path: /etc/pam.d/password-auth

          - name: 'Limit Password Reuse: password-auth - Check if system relies on authselect
              tool'
            ansible.builtin.stat:
              path: /usr/bin/authselect
            register: result_authselect_present

          - name: 'Limit Password Reuse: password-auth - Ensure authselect custom profile
              is used if authselect is present'
            block:

            - name: 'Limit Password Reuse: password-auth - Check integrity of authselect
                current profile'
              ansible.builtin.command:
                cmd: authselect check
              register: result_authselect_check_cmd
              changed_when: false
              check_mode: false
              failed_when: false

            - name: 'Limit Password Reuse: password-auth - Informative message based on
                the authselect integrity check result'
              ansible.builtin.assert:
                that:
                - ansible_check_mode or result_authselect_check_cmd.rc == 0
                fail_msg:
                - authselect integrity check failed. Remediation aborted!
                - This remediation could not be applied because an authselect profile
                  was not selected or the selected profile is not intact.
                - It is not recommended to manually edit the PAM files when authselect
                  tool is available.
                - In cases where the default authselect profile does not cover a specific
                  demand, a custom authselect profile is recommended.
                success_msg:
                - authselect integrity check passed

            - name: 'Limit Password Reuse: password-auth - Get authselect current profile'
              ansible.builtin.shell:
                cmd: authselect current -r | awk '{ print $1 }'
              register: result_authselect_profile
              changed_when: false
              when:
              - result_authselect_check_cmd is success

            - name: 'Limit Password Reuse: password-auth - Define the current authselect
                profile as a local fact'
              ansible.builtin.set_fact:
                authselect_current_profile: '{{ result_authselect_profile.stdout }}'
                authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
              when:
              - result_authselect_profile is not skipped
              - result_authselect_profile.stdout is match("custom/")

            - name: 'Limit Password Reuse: password-auth - Define the new authselect custom
                profile as a local fact'
              ansible.builtin.set_fact:
                authselect_current_profile: '{{ result_authselect_profile.stdout }}'
                authselect_custom_profile: custom/hardening
              when:
              - result_authselect_profile is not skipped
              - result_authselect_profile.stdout is not match("custom/")

            - name: 'Limit Password Reuse: password-auth - Get authselect current features
                to also enable them in the custom profile'
              ansible.builtin.shell:
                cmd: authselect current | tail -n+3 | awk '{ print $2 }'
              register: result_authselect_features
              changed_when: false
              check_mode: false
              when:
              - result_authselect_profile is not skipped
              - authselect_current_profile is not match("custom/")

            - name: 'Limit Password Reuse: password-auth - Check if any custom profile
                with the same name was already created'
              ansible.builtin.stat:
                path: /etc/authselect/{{ authselect_custom_profile }}
              register: result_authselect_custom_profile_present
              changed_when: false
              when:
              - result_authselect_profile is not skipped
              - authselect_current_profile is not match("custom/")

            - name: 'Limit Password Reuse: password-auth - Create an authselect custom
                profile based on the current profile'
              ansible.builtin.command:
                cmd: authselect create-profile hardening -b {{ authselect_current_profile
                  }}
              when:
              - result_authselect_profile is not skipped
              - result_authselect_check_cmd is success
              - authselect_current_profile is not match("^(custom/|local)")
              - not result_authselect_custom_profile_present.stat.exists

            - name: 'Limit Password Reuse: password-auth - Create an authselect custom
                profile based on sssd profile'
              ansible.builtin.command:
                cmd: authselect create-profile hardening -b sssd
              when:
              - result_authselect_profile is not skipped
              - result_authselect_check_cmd is success
              - authselect_current_profile is match("local")
              - not result_authselect_custom_profile_present.stat.exists

            - name: 'Limit Password Reuse: password-auth - Ensure authselect changes are
                applied'
              ansible.builtin.command:
                cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
              when:
              - result_authselect_check_cmd is success
              - result_authselect_profile is not skipped
              - authselect_current_profile is not match("custom/")
              - authselect_custom_profile is not match(authselect_current_profile)

            - name: 'Limit Password Reuse: password-auth - Ensure the authselect custom
                profile is selected'
              ansible.builtin.command:
                cmd: authselect select {{ authselect_custom_profile }}
              register: result_pam_authselect_select_profile
              when:
              - result_authselect_check_cmd is success
              - result_authselect_profile is not skipped
              - authselect_current_profile is not match("custom/")
              - authselect_custom_profile is not match(authselect_current_profile)

            - name: 'Limit Password Reuse: password-auth - Restore the authselect features
                in the custom profile'
              ansible.builtin.command:
                cmd: authselect enable-feature {{ item }}
              loop: '{{ result_authselect_features.stdout_lines }}'
              register: result_pam_authselect_restore_features
              when:
              - result_authselect_profile is not skipped
              - result_authselect_features is not skipped
              - result_pam_authselect_select_profile is not skipped

            - name: 'Limit Password Reuse: password-auth - Ensure authselect changes are
                applied'
              ansible.builtin.command:
                cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
              when:
              - result_authselect_check_cmd is success
              - result_authselect_profile is not skipped
              - result_pam_authselect_restore_features is not skipped

            - name: 'Limit Password Reuse: password-auth - Change the PAM file to be edited
                according to the custom authselect profile'
              ansible.builtin.set_fact:
                pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
                  | basename }}
              when:
              - authselect_custom_profile is defined
            when:
            - result_authselect_present.stat.exists

          - name: 'Limit Password Reuse: password-auth - Define a fact for control already
              filtered in case filters are used'
            ansible.builtin.set_fact:
              pam_module_control: ''

          - name: 'Limit Password Reuse: password-auth - Check if {{ pam_file_path }}
              file is present'
            ansible.builtin.stat:
              path: '{{ pam_file_path }}'
            register: result_pam_file_present

          - name: 'Limit Password Reuse: password-auth - Ensure the "remember" option
              from "pam_pwhistory.so" is not present in {{ pam_file_path }}'
            ansible.builtin.replace:
              dest: '{{ pam_file_path }}'
              regexp: (.*password.*pam_pwhistory.so.*)\bremember\b=?[0-9a-zA-Z]*(.*)
              replace: \1\2
            register: result_pam_option_removal
            when:
            - result_pam_file_present.stat.exists

          - name: 'Limit Password Reuse: password-auth - Ensure authselect changes are
              applied'
            ansible.builtin.command:
              cmd: authselect apply-changes -b
            when:
            - result_authselect_present.stat.exists
            - result_pam_option_removal is changed
          when:
          - result_pam_password_auth_file_present.stat.exists
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_pwhistory_conf_check.stat.exists
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_password_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: 'Limit Password Reuse: password-auth - pam_pwhistory.so parameters are configured
        in PAM files'
      block:

      - name: 'Limit Password Reuse: password-auth - Define the PAM file to be edited
          as a local fact'
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/password-auth

      - name: 'Limit Password Reuse: password-auth - Check if system relies on authselect
          tool'
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: 'Limit Password Reuse: password-auth - Ensure authselect custom profile
          is used if authselect is present'
        block:

        - name: 'Limit Password Reuse: password-auth - Check integrity of authselect current
            profile'
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          check_mode: false
          failed_when: false

        - name: 'Limit Password Reuse: password-auth - Informative message based on the
            authselect integrity check result'
          ansible.builtin.assert:
            that:
            - ansible_check_mode or result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: 'Limit Password Reuse: password-auth - Get authselect current profile'
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: 'Limit Password Reuse: password-auth - Define the current authselect profile
            as a local fact'
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: 'Limit Password Reuse: password-auth - Define the new authselect custom
            profile as a local fact'
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: 'Limit Password Reuse: password-auth - Get authselect current features
            to also enable them in the custom profile'
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          check_mode: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: 'Limit Password Reuse: password-auth - Check if any custom profile with
            the same name was already created'
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: 'Limit Password Reuse: password-auth - Create an authselect custom profile
            based on the current profile'
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("^(custom/|local)")
          - not result_authselect_custom_profile_present.stat.exists

        - name: 'Limit Password Reuse: password-auth - Create an authselect custom profile
            based on sssd profile'
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b sssd
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is match("local")
          - not result_authselect_custom_profile_present.stat.exists

        - name: 'Limit Password Reuse: password-auth - Ensure authselect changes are applied'
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: 'Limit Password Reuse: password-auth - Ensure the authselect custom profile
            is selected'
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: 'Limit Password Reuse: password-auth - Restore the authselect features
            in the custom profile'
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: 'Limit Password Reuse: password-auth - Ensure authselect changes are applied'
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: 'Limit Password Reuse: password-auth - Change the PAM file to be edited
            according to the custom authselect profile'
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
          when:
          - authselect_custom_profile is defined
        when:
        - result_authselect_present.stat.exists

      - name: 'Limit Password Reuse: password-auth - Define a fact for control already
          filtered in case filters are used'
        ansible.builtin.set_fact:
          pam_module_control: requisite

      - name: 'Limit Password Reuse: password-auth - Check if expected PAM module line
          is present in {{ pam_file_path }}'
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so\s*.*
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_line_present

      - name: 'Limit Password Reuse: password-auth - Include or update the PAM module
          line in {{ pam_file_path }}'
        block:

        - name: 'Limit Password Reuse: password-auth - Check if required PAM module line
            is present in {{ pam_file_path }} with different control'
          ansible.builtin.lineinfile:
            path: '{{ pam_file_path }}'
            regexp: ^\s*password\s+.*\s+pam_pwhistory.so\s*
            state: absent
          check_mode: true
          changed_when: false
          register: result_pam_line_other_control_present

        - name: 'Limit Password Reuse: password-auth - Ensure the correct control for
            the required PAM module line in {{ pam_file_path }}'
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: ^(\s*password\s+).*(\bpam_pwhistory.so.*)
            replace: \1{{ pam_module_control }} \2
          register: result_pam_module_edit
          when:
          - result_pam_line_other_control_present.found == 1

        - name: 'Limit Password Reuse: password-auth - Ensure the required PAM module
            line is included in {{ pam_file_path }}'
          ansible.builtin.lineinfile:
            dest: '{{ pam_file_path }}'
            line: password    {{ pam_module_control }}    pam_pwhistory.so
          register: result_pam_module_add
          when:
          - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
            > 1

        - name: 'Limit Password Reuse: password-auth - Ensure authselect changes are applied'
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present is defined
          - result_authselect_present.stat.exists
          - |-
            (result_pam_module_add is defined and result_pam_module_add.changed)
             or (result_pam_module_edit is defined and result_pam_module_edit.changed)
        when:
        - result_pam_line_present.found is defined
        - result_pam_line_present.found == 0

      - name: 'Limit Password Reuse: password-auth - Define a fact for control already
          filtered in case filters are used'
        ansible.builtin.set_fact:
          pam_module_control: requisite

      - name: 'Limit Password Reuse: password-auth - Check if the required PAM module
          option is present in {{ pam_file_path }}'
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so\s*.*\sremember\b
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_module_accounts_password_pam_pwhistory_remember_password_auth_option_present

      - name: 'Limit Password Reuse: password-auth - Ensure the "remember" PAM option
          for "pam_pwhistory.so" is included in {{ pam_file_path }}'
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          backrefs: true
          regexp: ^(\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so.*)
          line: \1 remember={{ var_password_pam_remember }}
          state: present
        register: result_pam_accounts_password_pam_pwhistory_remember_password_auth_add
        when:
        - result_pam_module_accounts_password_pam_pwhistory_remember_password_auth_option_present.found
          is defined
        - result_pam_module_accounts_password_pam_pwhistory_remember_password_auth_option_present.found
          == 0

      - name: 'Limit Password Reuse: password-auth - Ensure the required value for "remember"
          PAM option from "pam_pwhistory.so" in {{ pam_file_path }}'
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          backrefs: true
          regexp: ^(\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so\s+.*)(remember)=[0-9a-zA-Z]*\s*(.*)
          line: \1\2={{ var_password_pam_remember }} \3
        register: result_pam_accounts_password_pam_pwhistory_remember_password_auth_edit
        when:
        - result_pam_module_accounts_password_pam_pwhistory_remember_password_auth_option_present.found
          > 0

      - name: 'Limit Password Reuse: password-auth - Ensure authselect changes are applied'
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present.stat.exists
        - (result_pam_remember_add is defined and result_pam_remember_add.changed) or
          (result_pam_remember_edit is defined and result_pam_remember_edit.changed)
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - not result_pwhistory_conf_check.stat.exists
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_password_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Limit Password Reuse: system-auth [ref]
Do not allow users to reuse recent passwords. This can be accomplished by using the `remember` option for the `pam_pwhistory` PAM module. On systems with newer versions of `authselect`, the `pam_pwhistory` PAM module can be enabled via authselect feature:
    authselect enable-feature with-pwhistory
Otherwise, it should be enabled using an authselect custom profile. Newer systems also have the `/etc/security/pwhistory.conf` file for setting `pam_pwhistory` module options. This file should be used whenever available. Otherwise, the `pam_pwhistory` module options can be set in PAM files. The value for `remember` option must be equal or greater than 5 Warning: If the system relies on `authselect` tool to manage PAM settings, the remediation will also use `authselect` tool. However, if any manual modification was made in PAM files, the `authselect` integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. Warning: Newer versions of `authselect` contain an authselect feature to easily and properly enable `pam_pwhistory.so` module. If this feature is not yet available in your system, an authselect custom profile must be used to avoid integrity issues in PAM files.
Rationale: | Preventing reuse of previous passwords helps ensure that a compromised password is not reused by a user.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_pwhistory_remember_system_auth
References: |
cis-csc | 1, 12, 15, 16, 5
cjis | 5.6.2.1.1
cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.5.8
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1
iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nist | IA-5(f), IA-5(1)(e)
nist-csf | PR.AC-1, PR.AC-6, PR.AC-7
pcidss | Req-8.2.5
os-srg | SRG-OS-000077-GPOS-00045
cis | 4.5.3
pcidss4 | 8.3.7, 8.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q pam; }; then

    var_password_pam_remember='5'
    var_password_pam_remember_control_flag='requisite,required'

    var_password_pam_remember_control_flag="$(echo $var_password_pam_remember_control_flag | cut -d \, -f 1)"

    if [ -f /usr/bin/authselect ]; then
        if authselect list-features sssd | grep -q with-pwhistory; then
            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi
            authselect enable-feature with-pwhistory

            authselect apply-changes -b
        else

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                # The "local" profile does not contain essential security features required by multiple Benchmarks.
                # If currently used, it is replaced by "sssd", which is the best option in this case.
                if [[ $CURRENT_PROFILE == local ]]; then
                    CURRENT_PROFILE="sssd"
                fi
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b

            if ! grep -qP "^\s*password\s+\$var_password_pam_remember_control_flag\s+pam_pwhistory.so\s*.*" "$PAM_FILE_PATH"; then
                # Line matching group + control + module was not found. Check group + module.
                if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwhistory.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                    # The control is updated only if one single line matches.
                    sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_pwhistory.so.*)/\1$var_password_pam_remember_control_flag \2/" "$PAM_FILE_PATH"
                else
                    LAST_MATCH_LINE=$(grep -nP "^password.*requisite.*pam_pwquality\.so" "$PAM_FILE_PATH" | tail -n 1 | cut -d: -f 1)
                    if [ ! -z $LAST_MATCH_LINE ]; then
                        sed -i --follow-symlinks $LAST_MATCH_LINE" a password     $var_password_pam_remember_control_flag    pam_pwhistory.so" "$PAM_FILE_PATH"
                    else
                        echo "password    $var_password_pam_remember_control_flag    pam_pwhistory.so" >> "$PAM_FILE_PATH"
                    fi
                fi
            fi
        fi
    else

        if ! grep -qP "^\s*password\s+\$var_password_pam_remember_control_flag\s+pam_pwhistory.so\s*.*" "/etc/pam.d/system-auth"; then
            # Line matching group + control + module was not found. Check group + module.
            if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwhistory.so\s*' "/etc/pam.d/system-auth")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_pwhistory.so.*)/\1$var_password_pam_remember_control_flag \2/" "/etc/pam.d/system-auth"
            else
                LAST_MATCH_LINE=$(grep -nP "^password.*requisite.*pam_pwquality\.so" "/etc/pam.d/system-auth" | tail -n 1 | cut -d: -f 1)
                if [ ! -z $LAST_MATCH_LINE ]; then
                    sed -i --follow-symlinks $LAST_MATCH_LINE" a password     $var_password_pam_remember_control_flag    pam_pwhistory.so" "/etc/pam.d/system-auth"
                else
                    echo "password    $var_password_pam_remember_control_flag    pam_pwhistory.so" >> "/etc/pam.d/system-auth"
                fi
            fi
        fi

    fi

    PWHISTORY_CONF="/etc/security/pwhistory.conf"
    if [ -f $PWHISTORY_CONF ]; then
        regex="^\s*remember\s*="
        line="remember = $var_password_pam_remember"
        if ! grep -q $regex $PWHISTORY_CONF; then
            echo $line >> $PWHISTORY_CONF
        else
            sed -i --follow-symlinks 's|^\s*\(remember\s*=\s*\)\(\S\+\)|\1'"$var_password_pam_remember"'|g' $PWHISTORY_CONF
        fi
        if [ -e "/etc/pam.d/system-auth" ] ; then
            PAM_FILE_PATH="/etc/pam.d/system-auth"
            if [ -f /usr/bin/authselect ]; then

                if ! authselect check; then
                echo "
                authselect integrity check failed. Remediation aborted!
                This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
                It is not recommended to manually edit the PAM files when authselect tool is available.
                In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
                exit 1
                fi

                CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
                # If not already in use, a custom profile is created preserving the enabled features.
                if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                    ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                    # The "local" profile does not contain essential security features required by multiple Benchmarks.
                    # If currently used, it is replaced by "sssd", which is the best option in this case.
                    if [[ $CURRENT_PROFILE == local ]]; then
                        CURRENT_PROFILE="sssd"
                    fi
                    authselect create-profile hardening -b $CURRENT_PROFILE
                    CURRENT_PROFILE="custom/hardening"

                    authselect apply-changes -b --backup=before-hardening-custom-profile
                    authselect select $CURRENT_PROFILE
                    for feature in $ENABLED_FEATURES; do
                        authselect enable-feature $feature;
                    done

                    authselect apply-changes -b --backup=after-hardening-custom-profile
                fi
                PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
                PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

                authselect apply-changes -b
            fi

        if grep -qP "^\s*password\s.*\bpam_pwhistory.so\s.*\bremember\b" "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks "s/(.*password.*pam_pwhistory.so.*)\bremember\b=?[[:alnum:]]*(.*)/\1\2/g" "$PAM_FILE_PATH"
        fi
            if [ -f /usr/bin/authselect ]; then

                authselect apply-changes -b
            fi
        else
            echo "/etc/pam.d/system-auth was not found" >&2
        fi
    else
        PAM_FILE_PATH="/etc/pam.d/system-auth"
        if [ -f /usr/bin/authselect ]; then

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                # The "local" profile does not contain essential security features required by multiple Benchmarks.
                # If currently used, it is replaced by "sssd", which is the best option in this case.
                if [[ $CURRENT_PROFILE == local ]]; then
                    CURRENT_PROFILE="sssd"
                fi
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
        fi

        if ! grep -qP "^\s*password\s+requisite\s+pam_pwhistory.so\s*.*" "$PAM_FILE_PATH"; then
            # Line matching group + control + module was not found. Check group + module.
            if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwhistory.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                # The control is updated only if one single line matches.
                sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_pwhistory.so.*)/\1requisite \2/" "$PAM_FILE_PATH"
            else
                echo "password    requisite    pam_pwhistory.so" >> "$PAM_FILE_PATH"
            fi
        fi
        # Check the option
        if ! grep -qP "^\s*password\s+requisite\s+pam_pwhistory.so\s*.*\sremember\b" "$PAM_FILE_PATH"; then
            sed -i -E --follow-symlinks "/\s*password\s+requisite\s+pam_pwhistory.so.*/ s/$/ remember=$var_password_pam_remember/" "$PAM_FILE_PATH"
        else
            sed -i -E --follow-symlinks "s/(\s*password\s+requisite\s+pam_pwhistory.so\s+.*)(remember=)[[:alnum:]]*\s*(.*)/\1\2$var_password_pam_remember \3/" "$PAM_FILE_PATH"
        fi
        if [ -f /usr/bin/authselect ]; then

            authselect apply-changes -b
        fi
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_system_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
    - name: XCCDF Value var_password_pam_remember # promote to variable
      set_fact:
        var_password_pam_remember: !!str 5
      tags:
        - always
    - name: XCCDF Value var_password_pam_remember_control_flag # promote to variable
      set_fact:
        var_password_pam_remember_control_flag: !!str requisite,required
      tags:
        - always

    - name: 'Limit Password Reuse: system-auth - Check if system relies on authselect
        tool'
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_system_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: 'Limit Password Reuse: system-auth - Collect the available authselect features'
      ansible.builtin.command:
        cmd: authselect list-features sssd
      register: result_authselect_available_features
      changed_when: false
      check_mode: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_authselect_present.stat.exists
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_system_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: 'Limit Password Reuse: system-auth - Enable pam_pwhistory.so using authselect
        feature'
      block:

      - name: 'Limit Password Reuse: system-auth - Check integrity of authselect current
          profile'
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        check_mode: false
        failed_when: false

      - name: 'Limit Password Reuse: system-auth - Informative message based on the authselect
          integrity check result'
        ansible.builtin.assert:
          that:
          - ansible_check_mode or result_authselect_check_cmd.rc == 0
          fail_msg:
          - authselect integrity check failed. Remediation aborted!
          - This remediation could not be applied because an authselect profile was not
            selected or the selected profile is not intact.
          - It is not recommended to manually edit the PAM files when authselect tool
            is available.
          - In cases where the default authselect profile does not cover a specific demand,
            a custom authselect profile is recommended.
          success_msg:
          - authselect integrity check passed

      - name: 'Limit Password Reuse: system-auth - Get authselect current features'
        ansible.builtin.shell:
          cmd: authselect current | tail -n+3 | awk '{ print $2 }'
        register: result_authselect_features
        changed_when: false
        check_mode: false
        when:
        - result_authselect_check_cmd is success

      - name: 'Limit Password Reuse: system-auth - Ensure "with-pwhistory" feature is
          enabled using authselect tool'
        ansible.builtin.command:
          cmd: authselect enable-feature with-pwhistory
        register: result_authselect_enable_feature_cmd
        when:
        - result_authselect_check_cmd is success
        - result_authselect_features.stdout is not search("with-pwhistory")

      - name: 'Limit Password Reuse: system-auth - Ensure authselect changes are applied'
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_enable_feature_cmd is not skipped
        - result_authselect_enable_feature_cmd is success
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_authselect_present.stat.exists
      - result_authselect_available_features.stdout is search("with-pwhistory")
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_system_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: 'Limit Password Reuse: system-auth - Enable pam_pwhistory.so in appropriate
        PAM files'
      block:

      - name: 'Limit Password Reuse: system-auth - Define the PAM file to be edited as
          a local fact'
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/system-auth

      - name: 'Limit Password Reuse: system-auth - Check if system relies on authselect
          tool'
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: 'Limit Password Reuse: system-auth - Ensure authselect custom profile is
          used if authselect is present'
        block:

        - name: 'Limit Password Reuse: system-auth - Check integrity of authselect current
            profile'
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          check_mode: false
          failed_when: false

        - name: 'Limit Password Reuse: system-auth - Informative message based on the
            authselect integrity check result'
          ansible.builtin.assert:
            that:
            - ansible_check_mode or result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: 'Limit Password Reuse: system-auth - Get authselect current profile'
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: 'Limit Password Reuse: system-auth - Define the current authselect profile
            as a local fact'
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: 'Limit Password Reuse: system-auth - Define the new authselect custom
            profile as a local fact'
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: 'Limit Password Reuse: system-auth - Get authselect current features to
            also enable them in the custom profile'
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          check_mode: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: 'Limit Password Reuse: system-auth - Check if any custom profile with
            the same name was already created'
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: 'Limit Password Reuse: system-auth - Create an authselect custom profile
            based on the current profile'
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("^(custom/|local)")
          - not result_authselect_custom_profile_present.stat.exists

        - name: 'Limit Password Reuse: system-auth - Create an authselect custom profile
            based on sssd profile'
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b sssd
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is match("local")
          - not result_authselect_custom_profile_present.stat.exists

        - name: 'Limit Password Reuse: system-auth - Ensure authselect changes are applied'
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: 'Limit Password Reuse: system-auth - Ensure the authselect custom profile
            is selected'
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: 'Limit Password Reuse: system-auth - Restore the authselect features in
            the custom profile'
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: 'Limit Password Reuse: system-auth - Ensure authselect changes are applied'
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: 'Limit Password Reuse: system-auth - Change the PAM file to be edited
            according to the custom authselect profile'
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
          when:
          - authselect_custom_profile is defined
        when:
        - result_authselect_present.stat.exists

      - name: 'Limit Password Reuse: system-auth - Define a fact for control already filtered
          in case filters are used'
        ansible.builtin.set_fact:
          pam_module_control: '{{ var_password_pam_remember_control_flag.split(",")[0]
            }}'

      - name: 'Limit Password Reuse: system-auth - Check if expected PAM module line is
          present in {{ pam_file_path }}'
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so\s*.*
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_line_present

      - name: 'Limit Password Reuse: system-auth - Include or update the PAM module line
          in {{ pam_file_path }}'
        block:

        - name: 'Limit Password Reuse: system-auth - Check if required PAM module line
            is present in {{ pam_file_path }} with different control'
          ansible.builtin.lineinfile:
            path: '{{ pam_file_path }}'
            regexp: ^\s*password\s+.*\s+pam_pwhistory.so\s*
            state: absent
          check_mode: true
          changed_when: false
          register: result_pam_line_other_control_present

        - name: 'Limit Password Reuse: system-auth - Ensure the correct control for the
            required PAM module line in {{ pam_file_path }}'
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: ^(\s*password\s+).*(\bpam_pwhistory.so.*)
            replace: \1{{ pam_module_control }} \2
          register: result_pam_module_edit
          when:
          - result_pam_line_other_control_present.found == 1

        - name: 'Limit Password Reuse: system-auth - Ensure the required PAM module line
            is included in {{ pam_file_path }}'
          ansible.builtin.lineinfile:
            dest: '{{ pam_file_path }}'
            insertafter: ^password.*requisite.*pam_pwquality\.so
            line: password    {{ pam_module_control }}    pam_pwhistory.so
          register: result_pam_module_add
          when:
          - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
            > 1

        - name: 'Limit Password Reuse: system-auth - Ensure authselect changes are applied'
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present is defined
          - result_authselect_present.stat.exists
          - |-
            (result_pam_module_add is defined and result_pam_module_add.changed)
             or (result_pam_module_edit is defined and result_pam_module_edit.changed)
        when:
        - result_pam_line_present.found is defined
        - result_pam_line_present.found == 0
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - |
        (result_authselect_available_features.stdout is defined and result_authselect_available_features.stdout is not search("with-pwhistory")) or result_authselect_available_features is not defined
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_system_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: 'Limit Password Reuse: system-auth - Check the presence of /etc/security/pwhistory.conf
        file'
      ansible.builtin.stat:
        path: /etc/security/pwhistory.conf
      register: result_pwhistory_conf_check
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_system_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: 'Limit Password Reuse: system-auth - pam_pwhistory.so parameters are configured
        in /etc/security/pwhistory.conf file'
      block:

      - name: 'Limit Password Reuse: system-auth - Ensure the pam_pwhistory.so remember
          parameter in /etc/security/pwhistory.conf'
        ansible.builtin.lineinfile:
          path: /etc/security/pwhistory.conf
          regexp: ^\s*remember\s*=
          line: remember = {{ var_password_pam_remember }}
          state: present

      - name: 'Limit Password Reuse: system-auth - Ensure the pam_pwhistory.so remember
          parameter is removed from PAM files'
        block:

        - name: 'Limit Password Reuse: system-auth - Check if /etc/pam.d/system-auth file
            is present'
          ansible.builtin.stat:
            path: /etc/pam.d/system-auth
          register: result_pam_auth_file_present

        - name: 'Limit Password Reuse: system-auth - Check the proper remediation for
            the system'
          block:

          - name: 'Limit Password Reuse: system-auth - Define the PAM file to be edited
              as a local fact'
            ansible.builtin.set_fact:
              pam_file_path: /etc/pam.d/system-auth

          - name: 'Limit Password Reuse: system-auth - Check if system relies on authselect
              tool'
            ansible.builtin.stat:
              path: /usr/bin/authselect
            register: result_authselect_present

          - name: 'Limit Password Reuse: system-auth - Ensure authselect custom profile
              is used if authselect is present'
            block:

            - name: 'Limit Password Reuse: system-auth - Check integrity of authselect
                current profile'
              ansible.builtin.command:
                cmd: authselect check
              register: result_authselect_check_cmd
              changed_when: false
              check_mode: false
              failed_when: false

            - name: 'Limit Password Reuse: system-auth - Informative message based on
                the authselect integrity check result'
              ansible.builtin.assert:
                that:
                - ansible_check_mode or result_authselect_check_cmd.rc == 0
                fail_msg:
                - authselect integrity check failed. Remediation aborted!
                - This remediation could not be applied because an authselect profile
                  was not selected or the selected profile is not intact.
                - It is not recommended to manually edit the PAM files when authselect
                  tool is available.
                - In cases where the default authselect profile does not cover a specific
                  demand, a custom authselect profile is recommended.
                success_msg:
                - authselect integrity check passed

            - name: 'Limit Password Reuse: system-auth - Get authselect current profile'
              ansible.builtin.shell:
                cmd: authselect current -r | awk '{ print $1 }'
              register: result_authselect_profile
              changed_when: false
              when:
              - result_authselect_check_cmd is success

            - name: 'Limit Password Reuse: system-auth - Define the current authselect
                profile as a local fact'
              ansible.builtin.set_fact:
                authselect_current_profile: '{{ result_authselect_profile.stdout }}'
                authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
              when:
              - result_authselect_profile is not skipped
              - result_authselect_profile.stdout is match("custom/")

            - name: 'Limit Password Reuse: system-auth - Define the new authselect custom
                profile as a local fact'
              ansible.builtin.set_fact:
                authselect_current_profile: '{{ result_authselect_profile.stdout }}'
                authselect_custom_profile: custom/hardening
              when:
              - result_authselect_profile is not skipped
              - result_authselect_profile.stdout is not match("custom/")

            - name: 'Limit Password Reuse: system-auth - Get authselect current features
                to also enable them in the custom profile'
              ansible.builtin.shell:
                cmd: authselect current | tail -n+3 | awk '{ print $2 }'
              register: result_authselect_features
              changed_when: false
              check_mode: false
              when:
              - result_authselect_profile is not skipped
              - authselect_current_profile is not match("custom/")

            - name: 'Limit Password Reuse: system-auth - Check if any custom profile with
                the same name was already created'
              ansible.builtin.stat:
                path: /etc/authselect/{{ authselect_custom_profile }}
              register: result_authselect_custom_profile_present
              changed_when: false
              when:
              - result_authselect_profile is not skipped
              - authselect_current_profile is not match("custom/")

            - name: 'Limit Password Reuse: system-auth - Create an authselect custom profile
                based on the current profile'
              ansible.builtin.command:
                cmd: authselect create-profile hardening -b {{ authselect_current_profile
                  }}
              when:
              - result_authselect_profile is not skipped
              - result_authselect_check_cmd is success
              - authselect_current_profile is not match("^(custom/|local)")
              - not result_authselect_custom_profile_present.stat.exists

            - name: 'Limit Password Reuse: system-auth - Create an authselect custom profile
                based on sssd profile'
              ansible.builtin.command:
                cmd: authselect create-profile hardening -b sssd
              when:
              - result_authselect_profile is not skipped
              - result_authselect_check_cmd is success
              - authselect_current_profile is match("local")
              - not result_authselect_custom_profile_present.stat.exists

            - name: 'Limit Password Reuse: system-auth - Ensure authselect changes are
                applied'
              ansible.builtin.command:
                cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
              when:
              - result_authselect_check_cmd is success
              - result_authselect_profile is not skipped
              - authselect_current_profile is not match("custom/")
              - authselect_custom_profile is not match(authselect_current_profile)

            - name: 'Limit Password Reuse: system-auth - Ensure the authselect custom
                profile is selected'
              ansible.builtin.command:
                cmd: authselect select {{ authselect_custom_profile }}
              register: result_pam_authselect_select_profile
              when:
              - result_authselect_check_cmd is success
              - result_authselect_profile is not skipped
              - authselect_current_profile is not match("custom/")
              - authselect_custom_profile is not match(authselect_current_profile)

            - name: 'Limit Password Reuse: system-auth - Restore the authselect features
                in the custom profile'
              ansible.builtin.command:
                cmd: authselect enable-feature {{ item }}
              loop: '{{ result_authselect_features.stdout_lines }}'
              register: result_pam_authselect_restore_features
              when:
              - result_authselect_profile is not skipped
              - result_authselect_features is not skipped
              - result_pam_authselect_select_profile is not skipped

            - name: 'Limit Password Reuse: system-auth - Ensure authselect changes are
                applied'
              ansible.builtin.command:
                cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
              when:
              - result_authselect_check_cmd is success
              - result_authselect_profile is not skipped
              - result_pam_authselect_restore_features is not skipped

            - name: 'Limit Password Reuse: system-auth - Change the PAM file to be edited
                according to the custom authselect profile'
              ansible.builtin.set_fact:
                pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
                  | basename }}
              when:
              - authselect_custom_profile is defined
            when:
            - result_authselect_present.stat.exists

          - name: 'Limit Password Reuse: system-auth - Define a fact for control already
              filtered in case filters are used'
            ansible.builtin.set_fact:
              pam_module_control: ''

          - name: 'Limit Password Reuse: system-auth - Check if {{ pam_file_path }} file
              is present'
            ansible.builtin.stat:
              path: '{{ pam_file_path }}'
            register: result_pam_file_present

          - name: 'Limit Password Reuse: system-auth - Ensure the "remember" option from
              "pam_pwhistory.so" is not present in {{ pam_file_path }}'
            ansible.builtin.replace:
              dest: '{{ pam_file_path }}'
              regexp: (.*password.*pam_pwhistory.so.*)\bremember\b=?[0-9a-zA-Z]*(.*)
              replace: \1\2
            register: result_pam_option_removal
            when:
            - result_pam_file_present.stat.exists

          - name: 'Limit Password Reuse: system-auth - Ensure authselect changes are applied'
            ansible.builtin.command:
              cmd: authselect apply-changes -b
            when:
            - result_authselect_present.stat.exists
            - result_pam_option_removal is changed
          when:
          - result_pam_auth_file_present.stat.exists
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_pwhistory_conf_check.stat.exists
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_system_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: 'Limit Password Reuse: system-auth - pam_pwhistory.so parameters are configured
        in PAM files'
      block:

      - name: 'Limit Password Reuse: system-auth - Define the PAM file to be edited as
          a local fact'
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/system-auth

      - name: 'Limit Password Reuse: system-auth - Check if system relies on authselect
          tool'
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: 'Limit Password Reuse: system-auth - Ensure authselect custom profile is
          used if authselect is present'
        block:

        - name: 'Limit Password Reuse: system-auth - Check integrity of authselect current
            profile'
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          check_mode: false
          failed_when: false

        - name: 'Limit Password Reuse: system-auth - Informative message based on the
            authselect integrity check result'
          ansible.builtin.assert:
            that:
            - ansible_check_mode or result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: 'Limit Password Reuse: system-auth - Get authselect current profile'
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: 'Limit Password Reuse: system-auth - Define the current authselect profile
            as a local fact'
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: 'Limit Password Reuse: system-auth - Define the new authselect custom
            profile as a local fact'
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: 'Limit Password Reuse: system-auth - Get authselect current features to
            also enable them in the custom profile'
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          check_mode: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: 'Limit Password Reuse: system-auth - Check if any custom profile with
            the same name was already created'
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: 'Limit Password Reuse: system-auth - Create an authselect custom profile
            based on the current profile'
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("^(custom/|local)")
          - not result_authselect_custom_profile_present.stat.exists

        - name: 'Limit Password Reuse: system-auth - Create an authselect custom profile
            based on sssd profile'
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b sssd
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is match("local")
          - not result_authselect_custom_profile_present.stat.exists

        - name: 'Limit Password Reuse: system-auth - Ensure authselect changes are applied'
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: 'Limit Password Reuse: system-auth - Ensure the authselect custom profile
            is selected'
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: 'Limit Password Reuse: system-auth - Restore the authselect features in
            the custom profile'
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: 'Limit Password Reuse: system-auth - Ensure authselect changes are applied'
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: 'Limit Password Reuse: system-auth - Change the PAM file to be edited
            according to the custom authselect profile'
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
          when:
          - authselect_custom_profile is defined
        when:
        - result_authselect_present.stat.exists

      - name: 'Limit Password Reuse: system-auth - Define a fact for control already filtered
          in case filters are used'
        ansible.builtin.set_fact:
          pam_module_control: requisite

      - name: 'Limit Password Reuse: system-auth - Check if expected PAM module line is
          present in {{ pam_file_path }}'
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so\s*.*
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_line_present

      - name: 'Limit Password Reuse: system-auth - Include or update the PAM module line
          in {{ pam_file_path }}'
        block:

        - name: 'Limit Password Reuse: system-auth - Check if required PAM module line
            is present in {{ pam_file_path }} with different control'
          ansible.builtin.lineinfile:
            path: '{{ pam_file_path }}'
            regexp: ^\s*password\s+.*\s+pam_pwhistory.so\s*
            state: absent
          check_mode: true
          changed_when: false
          register: result_pam_line_other_control_present

        - name: 'Limit Password Reuse: system-auth - Ensure the correct control for the
            required PAM module line in {{ pam_file_path }}'
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: ^(\s*password\s+).*(\bpam_pwhistory.so.*)
            replace: \1{{ pam_module_control }} \2
          register: result_pam_module_edit
          when:
          - result_pam_line_other_control_present.found == 1

        - name: 'Limit Password Reuse: system-auth - Ensure the required PAM module line
            is included in {{ pam_file_path }}'
          ansible.builtin.lineinfile:
            dest: '{{ pam_file_path }}'
            line: password    {{ pam_module_control }}    pam_pwhistory.so
          register: result_pam_module_add
          when:
          - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
            > 1

        - name: 'Limit Password Reuse: system-auth - Ensure authselect changes are applied'
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present is defined
          - result_authselect_present.stat.exists
          - |-
            (result_pam_module_add is defined and result_pam_module_add.changed)
             or (result_pam_module_edit is defined and result_pam_module_edit.changed)
        when:
        - result_pam_line_present.found is defined
        - result_pam_line_present.found == 0

      - name: 'Limit Password Reuse: system-auth - Define a fact for control already filtered
          in case filters are used'
        ansible.builtin.set_fact:
          pam_module_control: requisite

      - name: 'Limit Password Reuse: system-auth - Check if the required PAM module option
          is present in {{ pam_file_path }}'
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so\s*.*\sremember\b
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_module_accounts_password_pam_pwhistory_remember_system_auth_option_present

      - name: 'Limit Password Reuse: system-auth - Ensure the "remember" PAM option for
          "pam_pwhistory.so" is included in {{ pam_file_path }}'
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          backrefs: true
          regexp: ^(\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so.*)
          line: \1 remember={{ var_password_pam_remember }}
          state: present
        register: result_pam_accounts_password_pam_pwhistory_remember_system_auth_add
        when:
        - result_pam_module_accounts_password_pam_pwhistory_remember_system_auth_option_present.found
          is defined
        - result_pam_module_accounts_password_pam_pwhistory_remember_system_auth_option_present.found
          == 0

      - name: 'Limit Password Reuse: system-auth - Ensure the required value for "remember"
          PAM option from "pam_pwhistory.so" in {{ pam_file_path }}'
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          backrefs: true
          regexp: ^(\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwhistory.so\s+.*)(remember)=[0-9a-zA-Z]*\s*(.*)
          line: \1\2={{ var_password_pam_remember }} \3
        register: result_pam_accounts_password_pam_pwhistory_remember_system_auth_edit
        when:
        - result_pam_module_accounts_password_pam_pwhistory_remember_system_auth_option_present.found
          > 0

      - name: 'Limit Password Reuse: system-auth - Ensure authselect changes are applied'
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present.stat.exists
        - (result_pam_remember_add is defined and result_pam_remember_add.changed) or
          (result_pam_remember_edit is defined and result_pam_remember_edit.changed)
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - not result_pwhistory_conf_check.stat.exists
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-IA-5(1)(e)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.5
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.7
      - accounts_password_pam_pwhistory_remember_system_auth
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Lock Accounts After Failed Password Attempts [ref]
This rule configures the system to lock out accounts after a number of incorrect login attempts using `pam_faillock.so`. pam_faillock.so module requires multiple entries in pam files. These entries must be carefully defined to work as expected. Ensure that the file `/etc/security/faillock.conf` contains the following entry: `deny = <count>` Where count should be less than or equal to 3 and greater than 0. In order to avoid errors when manually editing these files, it is recommended to use the appropriate tools, such as `authselect` or `authconfig`, depending on the OS version. Warning: If the system relies on `authselect` tool to manage PAM settings, the remediation will also use `authselect` tool. However, if any manual modification was made in PAM files, the `authselect` integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. If the system supports the `/etc/security/faillock.conf` file, the pam_faillock parameters should be defined in `faillock.conf` file.
Rationale: | By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, also known as brute-forcing, is reduced. Limits are imposed by locking the account.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_deny
References: |
cis-csc | 1, 12, 15, 16
cjis | 5.5.3
cobit5 | DSS05.04, DSS05.10, DSS06.10
cui | 3.1.8
isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9
iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3
nist | CM-6(a), AC-7(a)
nist-csf | PR.AC-7
ospp | FIA_AFL.1
pcidss | Req-8.1.6
os-srg | SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005
anssi | R31
cis | 4.5.2
ism | 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561
pcidss4 | 8.3.4, 8.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q pam; }; then

    var_accounts_passwords_pam_faillock_deny='3'

    if [ -f /usr/bin/authselect ]; then
        if ! authselect check; then
    echo "
    authselect integrity check failed. Remediation aborted!
    This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
    It is not recommended to manually edit the PAM files when authselect tool is available.
    In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
    exit 1
    fi
    authselect enable-feature with-faillock

    authselect apply-changes -b
    else

    AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
    for pam_file in "${AUTH_FILES[@]}"
    do
        if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+(preauth silent|authfail).*$' "$pam_file" ; then
            sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix\.so.*/i auth        required      pam_faillock.so preauth silent' "$pam_file"
            sed -i --follow-symlinks '/^auth.*required.*pam_deny\.so.*/i auth        required      pam_faillock.so authfail' "$pam_file"
            sed -i --follow-symlinks '/^account.*required.*pam_unix\.so.*/i account     required      pam_faillock.so' "$pam_file"
        fi
        sed -Ei 's/(auth.*)(\[default=die\])(.*pam_faillock\.so)/\1required     \3/g' "$pam_file"
    done

    fi

    AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
    SKIP_FAILLOCK_CHECK=false

    FAILLOCK_CONF="/etc/security/faillock.conf"
    if [ -f $FAILLOCK_CONF ] || [ "$SKIP_FAILLOCK_CHECK" = "true" ]; then
        regex="^\s*deny\s*="
        line="deny = $var_accounts_passwords_pam_faillock_deny"
        if ! grep -q $regex $FAILLOCK_CONF; then
            echo $line >> $FAILLOCK_CONF
        else
            sed -i --follow-symlinks 's|^\s*\(deny\s*=\s*\)\(\S\+\)|\1'"$var_accounts_passwords_pam_faillock_deny"'|g' $FAILLOCK_CONF
        fi

        for pam_file in "${AUTH_FILES[@]}"
        do
            if [ -e "$pam_file" ] ; then
                PAM_FILE_PATH="$pam_file"
                if [ -f /usr/bin/authselect ]; then

                    if ! authselect check; then
                    echo "
                    authselect integrity check failed. Remediation aborted!
                    This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
                    It is not recommended to manually edit the PAM files when authselect tool is available.
                    In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
                    exit 1
                    fi

                    CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
                    # If not already in use, a custom profile is created preserving the enabled features.
                    if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                        ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                        # The "local" profile does not contain essential security features required by multiple Benchmarks.
                        # If currently used, it is replaced by "sssd", which is the best option in this case.
                        if [[ $CURRENT_PROFILE == local ]]; then
                            CURRENT_PROFILE="sssd"
                        fi
                        authselect create-profile hardening -b $CURRENT_PROFILE
                        CURRENT_PROFILE="custom/hardening"

                        authselect apply-changes -b --backup=before-hardening-custom-profile
                        authselect select $CURRENT_PROFILE
                        for feature in $ENABLED_FEATURES; do
                            authselect enable-feature $feature;
                        done

                        authselect apply-changes -b --backup=after-hardening-custom-profile
                    fi
                    PAM_FILE_NAME=$(basename "$pam_file")
                    PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

                    authselect apply-changes -b
                fi

            if grep -qP "^\s*auth\s.*\bpam_faillock.so\s.*\bdeny\b" "$PAM_FILE_PATH"; then
                sed -i -E --follow-symlinks "s/(.*auth.*pam_faillock.so.*)\bdeny\b=?[[:alnum:]]*(.*)/\1\2/g" "$PAM_FILE_PATH"
            fi
                if [ -f /usr/bin/authselect ]; then

                    authselect apply-changes -b
                fi
            else
                echo "$pam_file was not found" >&2
            fi
        done

    else
        for pam_file in "${AUTH_FILES[@]}"
        do
            if ! grep -qE '^\s*auth.*pam_faillock\.so\s+(preauth|authfail).*deny' "$pam_file"; then
                sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*preauth.*/ s/$/ deny='"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
                sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*authfail.*/ s/$/ deny='"$var_accounts_passwords_pam_faillock_deny"'/' "$pam_file"
            else
                sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*preauth.*\)\('"deny"'=\)\S\+\b\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_deny"'\3/' "$pam_file"
                sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*authfail.*\)\('"deny"'=\)\S\+\b\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_deny"'\3/' "$pam_file"
            fi
        done
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Lock Accounts After Failed Password Attempts - Check if system relies on authselect
        tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Lock Accounts After Failed Password Attempts - Remediation where authselect
        tool is present
      block:

      - name: Lock Accounts After Failed Password Attempts - Check integrity of authselect
          current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        check_mode: false
        failed_when: false

      - name: Lock Accounts After Failed Password Attempts - Informative message based
          on the authselect integrity check result
        ansible.builtin.assert:
          that:
          - ansible_check_mode or result_authselect_check_cmd.rc == 0
          fail_msg:
          - authselect integrity check failed. Remediation aborted!
          - This remediation could not be applied because an authselect profile was not
            selected or the selected profile is not intact.
          - It is not recommended to manually edit the PAM files when authselect tool
            is available.
          - In cases where the default authselect profile does not cover a specific demand,
            a custom authselect profile is recommended.
          success_msg:
          - authselect integrity check passed

      - name: Lock Accounts After Failed Password Attempts - Get authselect current features
        ansible.builtin.shell:
          cmd: authselect current | tail -n+3 | awk '{ print $2 }'
        register: result_authselect_features
        changed_when: false
        check_mode: false
        when:
        - result_authselect_check_cmd is success

      - name: Lock Accounts After Failed Password Attempts - Ensure "with-faillock" feature
          is enabled using authselect tool
        ansible.builtin.command:
          cmd: authselect enable-feature with-faillock
        register: result_authselect_enable_feature_cmd
        when:
        - result_authselect_check_cmd is success
        - result_authselect_features.stdout is not search("with-faillock")

      - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_enable_feature_cmd is not skipped
        - result_authselect_enable_feature_cmd is success
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_authselect_present.stat.exists
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Lock Accounts After Failed Password Attempts - Remediation where authselect
        tool is not present
      block:

      - name: Lock Accounts After Failed Password Attempts - Check if pam_faillock.so
          is already enabled
        ansible.builtin.lineinfile:
          path: /etc/pam.d/system-auth
          regexp: .*auth.*pam_faillock\.so (preauth|authfail)
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_faillock_is_enabled

      - name: Lock Accounts After Failed Password Attempts - Enable pam_faillock.so preauth
          editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: auth        required      pam_faillock.so preauth
          insertbefore: ^auth.*sufficient.*pam_unix\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0

      - name: Lock Accounts After Failed Password Attempts - Enable pam_faillock.so authfail
          editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: auth        required      pam_faillock.so authfail
          insertbefore: ^auth.*required.*pam_deny\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0

      - name: Lock Accounts After Failed Password Attempts - Enable pam_faillock.so account
          section editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: account     required      pam_faillock.so
          insertbefore: ^account.*required.*pam_unix\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - not result_authselect_present.stat.exists
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_passwords_pam_faillock_deny # promote to variable
      set_fact:
        var_accounts_passwords_pam_faillock_deny: !!str 3
      tags:
        - always

    - name: Lock Accounts After Failed Password Attempts - Check the presence of /etc/security/faillock.conf
        file
      ansible.builtin.stat:
        path: /etc/security/faillock.conf
      register: result_faillock_conf_check
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Lock Accounts After Failed Password Attempts - Ensure the pam_faillock.so
        deny parameter in /etc/security/faillock.conf
      ansible.builtin.lineinfile:
        path: /etc/security/faillock.conf
        regexp: ^\s*deny\s*=
        line: deny = {{ var_accounts_passwords_pam_faillock_deny }}
        state: present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_faillock_conf_check.stat.exists
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Lock Accounts After Failed Password Attempts - Ensure the pam_faillock.so
        deny parameter not in PAM files
      block:

      - name: Lock Accounts After Failed Password Attempts - Check if /etc/pam.d/system-auth
          file is present
        ansible.builtin.stat:
          path: /etc/pam.d/system-auth
        register: result_pam_auth_file_present

      - name: Lock Accounts After Failed Password Attempts - Check the proper remediation
          for the system
        block:

        - name: Lock Accounts After Failed Password Attempts - Define the PAM file to
            be edited as a local fact
          ansible.builtin.set_fact:
            pam_file_path: /etc/pam.d/system-auth

        - name: Lock Accounts After Failed Password Attempts - Check if system relies
            on authselect tool
          ansible.builtin.stat:
            path: /usr/bin/authselect
          register: result_authselect_present

        - name: Lock Accounts After Failed Password Attempts - Ensure authselect custom
            profile is used if authselect is present
          block:

          - name: Lock Accounts After Failed Password Attempts - Check integrity of authselect
              current profile
            ansible.builtin.command:
              cmd: authselect check
            register: result_authselect_check_cmd
            changed_when: false
            check_mode: false
            failed_when: false

          - name: Lock Accounts After Failed Password Attempts - Informative message based
              on the authselect integrity check result
            ansible.builtin.assert:
              that:
              - ansible_check_mode or result_authselect_check_cmd.rc == 0
              fail_msg:
              - authselect integrity check failed. Remediation aborted!
              - This remediation could not be applied because an authselect profile was
                not selected or the selected profile is not intact.
              - It is not recommended to manually edit the PAM files when authselect tool
                is available.
              - In cases where the default authselect profile does not cover a specific
                demand, a custom authselect profile is recommended.
              success_msg:
              - authselect integrity check passed

          - name: Lock Accounts After Failed Password Attempts - Get authselect current
              profile
            ansible.builtin.shell:
              cmd: authselect current -r | awk '{ print $1 }'
            register: result_authselect_profile
            changed_when: false
            when:
            - result_authselect_check_cmd is success

          - name: Lock Accounts After Failed Password Attempts - Define the current authselect
              profile as a local fact
            ansible.builtin.set_fact:
              authselect_current_profile: '{{ result_authselect_profile.stdout }}'
              authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
            when:
            - result_authselect_profile is not skipped
            - result_authselect_profile.stdout is match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Define the new authselect
              custom profile as a local fact
            ansible.builtin.set_fact:
              authselect_current_profile: '{{ result_authselect_profile.stdout }}'
              authselect_custom_profile: custom/hardening
            when:
            - result_authselect_profile is not skipped
            - result_authselect_profile.stdout is not match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Get authselect current
              features to also enable them in the custom profile
            ansible.builtin.shell:
              cmd: authselect current | tail -n+3 | awk '{ print $2 }'
            register: result_authselect_features
            changed_when: false
            check_mode: false
            when:
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Check if any custom profile
              with the same name was already created
            ansible.builtin.stat:
              path: /etc/authselect/{{ authselect_custom_profile }}
            register: result_authselect_custom_profile_present
            changed_when: false
            when:
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Create an authselect
              custom profile based on the current profile
            ansible.builtin.command:
              cmd: authselect create-profile hardening -b {{ authselect_current_profile
                }}
            when:
            - result_authselect_profile is not skipped
            - result_authselect_check_cmd is success
            - authselect_current_profile is not match("^(custom/|local)")
            - not result_authselect_custom_profile_present.stat.exists

          - name: Lock Accounts After Failed Password Attempts - Create an authselect
              custom profile based on sssd profile
            ansible.builtin.command:
              cmd: authselect create-profile hardening -b sssd
            when:
            - result_authselect_profile is not skipped
            - result_authselect_check_cmd is success
            - authselect_current_profile is match("local")
            - not result_authselect_custom_profile_present.stat.exists

          - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
              are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")
            - authselect_custom_profile is not match(authselect_current_profile)

          - name: Lock Accounts After Failed Password Attempts - Ensure the authselect
              custom profile is selected
            ansible.builtin.command:
              cmd: authselect select {{ authselect_custom_profile }}
            register: result_pam_authselect_select_profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")
            - authselect_custom_profile is not match(authselect_current_profile)

          - name: Lock Accounts After Failed Password Attempts - Restore the authselect
              features in the custom profile
            ansible.builtin.command:
              cmd: authselect enable-feature {{ item }}
            loop: '{{ result_authselect_features.stdout_lines }}'
            register: result_pam_authselect_restore_features
            when:
            - result_authselect_profile is not skipped
            - result_authselect_features is not skipped
            - result_pam_authselect_select_profile is not skipped

          - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
              are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - result_pam_authselect_restore_features is not skipped

          - name: Lock Accounts After Failed Password Attempts - Change the PAM file to
              be edited according to the custom authselect profile
            ansible.builtin.set_fact:
              pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
                | basename }}
            when:
            - authselect_custom_profile is defined
          when:
          - result_authselect_present.stat.exists

        - name: Lock Accounts After Failed Password Attempts - Define a fact for control
            already filtered in case filters are used
          ansible.builtin.set_fact:
            pam_module_control: ''

        - name: Lock Accounts After Failed Password Attempts - Check if {{ pam_file_path
            }} file is present
          ansible.builtin.stat:
            path: '{{ pam_file_path }}'
          register: result_pam_file_present

        - name: Lock Accounts After Failed Password Attempts - Ensure the "deny" option
            from "pam_faillock.so" is not present in {{ pam_file_path }}
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: (.*auth.*pam_faillock.so.*)\bdeny\b=?[0-9a-zA-Z]*(.*)
            replace: \1\2
          register: result_pam_option_removal
          when:
          - result_pam_file_present.stat.exists

        - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
            are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present.stat.exists
          - result_pam_option_removal is changed
        when:
        - result_pam_auth_file_present.stat.exists

      - name: Lock Accounts After Failed Password Attempts - Check if /etc/pam.d/password-auth
          file is present
        ansible.builtin.stat:
          path: /etc/pam.d/password-auth
        register: result_pam_password_auth_file_present

      - name: Lock Accounts After Failed Password Attempts - Check the proper remediation
          for the system
        block:

        - name: Lock Accounts After Failed Password Attempts - Define the PAM file to
            be edited as a local fact
          ansible.builtin.set_fact:
            pam_file_path: /etc/pam.d/password-auth

        - name: Lock Accounts After Failed Password Attempts - Check if system relies
            on authselect tool
          ansible.builtin.stat:
            path: /usr/bin/authselect
          register: result_authselect_present

        - name: Lock Accounts After Failed Password Attempts - Ensure authselect custom
            profile is used if authselect is present
          block:

          - name: Lock Accounts After Failed Password Attempts - Check integrity of authselect
              current profile
            ansible.builtin.command:
              cmd: authselect check
            register: result_authselect_check_cmd
            changed_when: false
            check_mode: false
            failed_when: false

          - name: Lock Accounts After Failed Password Attempts - Informative message based
              on the authselect integrity check result
            ansible.builtin.assert:
              that:
              - ansible_check_mode or result_authselect_check_cmd.rc == 0
              fail_msg:
              - authselect integrity check failed. Remediation aborted!
              - This remediation could not be applied because an authselect profile was
                not selected or the selected profile is not intact.
              - It is not recommended to manually edit the PAM files when authselect tool
                is available.
              - In cases where the default authselect profile does not cover a specific
                demand, a custom authselect profile is recommended.
              success_msg:
              - authselect integrity check passed

          - name: Lock Accounts After Failed Password Attempts - Get authselect current
              profile
            ansible.builtin.shell:
              cmd: authselect current -r | awk '{ print $1 }'
            register: result_authselect_profile
            changed_when: false
            when:
            - result_authselect_check_cmd is success

          - name: Lock Accounts After Failed Password Attempts - Define the current authselect
              profile as a local fact
            ansible.builtin.set_fact:
              authselect_current_profile: '{{ result_authselect_profile.stdout }}'
              authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
            when:
            - result_authselect_profile is not skipped
            - result_authselect_profile.stdout is match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Define the new authselect
              custom profile as a local fact
            ansible.builtin.set_fact:
              authselect_current_profile: '{{ result_authselect_profile.stdout }}'
              authselect_custom_profile: custom/hardening
            when:
            - result_authselect_profile is not skipped
            - result_authselect_profile.stdout is not match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Get authselect current
              features to also enable them in the custom profile
            ansible.builtin.shell:
              cmd: authselect current | tail -n+3 | awk '{ print $2 }'
            register: result_authselect_features
            changed_when: false
            check_mode: false
            when:
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Check if any custom profile
              with the same name was already created
            ansible.builtin.stat:
              path: /etc/authselect/{{ authselect_custom_profile }}
            register: result_authselect_custom_profile_present
            changed_when: false
            when:
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")

          - name: Lock Accounts After Failed Password Attempts - Create an authselect
              custom profile based on the current profile
            ansible.builtin.command:
              cmd: authselect create-profile hardening -b {{ authselect_current_profile
                }}
            when:
            - result_authselect_profile is not skipped
            - result_authselect_check_cmd is success
            - authselect_current_profile is not match("^(custom/|local)")
            - not result_authselect_custom_profile_present.stat.exists

          - name: Lock Accounts After Failed Password Attempts - Create an authselect
              custom profile based on sssd profile
            ansible.builtin.command:
              cmd: authselect create-profile hardening -b sssd
            when:
            - result_authselect_profile is not skipped
            - result_authselect_check_cmd is success
            - authselect_current_profile is match("local")
            - not result_authselect_custom_profile_present.stat.exists

          - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
              are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")
            - authselect_custom_profile is not match(authselect_current_profile)

          - name: Lock Accounts After Failed Password Attempts - Ensure the authselect
              custom profile is selected
            ansible.builtin.command:
              cmd: authselect select {{ authselect_custom_profile }}
            register: result_pam_authselect_select_profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")
            - authselect_custom_profile is not match(authselect_current_profile)

          - name: Lock Accounts After Failed Password Attempts - Restore the authselect
              features in the custom profile
            ansible.builtin.command:
              cmd: authselect enable-feature {{ item }}
            loop: '{{ result_authselect_features.stdout_lines }}'
            register: result_pam_authselect_restore_features
            when:
            - result_authselect_profile is not skipped
            - result_authselect_features is not skipped
            - result_pam_authselect_select_profile is not skipped

          - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
              are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - result_pam_authselect_restore_features is not skipped

          - name: Lock Accounts After Failed Password Attempts - Change the PAM file to
              be edited according to the custom authselect profile
            ansible.builtin.set_fact:
              pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
                | basename }}
            when:
            - authselect_custom_profile is defined
          when:
          - result_authselect_present.stat.exists

        - name: Lock Accounts After Failed Password Attempts - Define a fact for control
            already filtered in case filters are used
          ansible.builtin.set_fact:
            pam_module_control: ''

        - name: Lock Accounts After Failed Password Attempts - Check if {{ pam_file_path
            }} file is present
          ansible.builtin.stat:
            path: '{{ pam_file_path }}'
          register: result_pam_file_present

        - name: Lock Accounts After Failed Password Attempts - Ensure the "deny" option
            from "pam_faillock.so" is not present in {{ pam_file_path }}
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: (.*auth.*pam_faillock.so.*)\bdeny\b=?[0-9a-zA-Z]*(.*)
            replace: \1\2
          register: result_pam_option_removal
          when:
          - result_pam_file_present.stat.exists

        - name: Lock Accounts After Failed Password Attempts - Ensure authselect changes
            are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present.stat.exists
          - result_pam_option_removal is changed
        when:
        - result_pam_password_auth_file_present.stat.exists
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_faillock_conf_check.stat.exists
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Lock Accounts After Failed Password Attempts - Ensure the pam_faillock.so
        deny parameter in PAM files
      block:

      - name: Lock Accounts After Failed Password Attempts - Check if pam_faillock.so
          deny parameter is already enabled in pam files
        ansible.builtin.lineinfile:
          path: /etc/pam.d/system-auth
          regexp: .*auth.*pam_faillock\.so (preauth|authfail).*deny
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_faillock_deny_parameter_is_present

      - name: Lock Accounts After Failed Password Attempts - Ensure the inclusion of pam_faillock.so
          preauth deny parameter in auth section
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          backrefs: true
          regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)
          line: \1required\3 deny={{ var_accounts_passwords_pam_faillock_deny }}
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_deny_parameter_is_present.found == 0

      - name: Lock Accounts After Failed Password Attempts - Ensure the inclusion of pam_faillock.so
          authfail deny parameter in auth section
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          backrefs: true
          regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)
          line: \1required\3 deny={{ var_accounts_passwords_pam_faillock_deny }}
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_deny_parameter_is_present.found == 0

      - name: Lock Accounts After Failed Password Attempts - Ensure the desired value
          for pam_faillock.so preauth deny parameter in auth section
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          backrefs: true
          regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)(deny)=[0-9]+(.*)
          line: \1required\3\4={{ var_accounts_passwords_pam_faillock_deny }}\5
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_deny_parameter_is_present.found > 0

      - name: Lock Accounts After Failed Password Attempts - Ensure the desired value
          for pam_faillock.so authfail deny parameter in auth section
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          backrefs: true
          regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)(deny)=[0-9]+(.*)
          line: \1required\3\4={{ var_accounts_passwords_pam_faillock_deny }}\5
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_deny_parameter_is_present.found > 0
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - not result_faillock_conf_check.stat.exists
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.6
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_deny
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Set Lockout Time for Failed Password Attempts [ref]
This rule configures the system to lock out accounts during a specified time period after a number of incorrect login attempts using `pam_faillock.so`. Ensure that the file `/etc/security/faillock.conf` contains the following entry: `unlock_time=<interval-in-seconds>` where `interval-in-seconds` is `900` or greater. pam_faillock.so module requires multiple entries in pam files. These entries must be carefully defined to work as expected. In order to avoid any errors when manually editing these files, it is recommended to use the appropriate tools, such as `authselect` or `authconfig`, depending on the OS version. If `unlock_time` is set to `0`, manual intervention by an administrator is required to unlock a user. This should be done using the `faillock` tool. Warning: If the system supports the new `/etc/security/faillock.conf` file but the pam_faillock.so parameters are defined directly in `/etc/pam.d/system-auth` and `/etc/pam.d/password-auth`, the remediation will migrate the `unlock_time` parameter to `/etc/security/faillock.conf` to ensure compatibility with `authselect` tool. The parameters `deny` and `fail_interval`, if used, also have to be migrated by their respective remediation. Warning: If the system relies on `authselect` tool to manage PAM settings, the remediation will also use `authselect` tool. However, if any manual modification was made in PAM files, the `authselect` integrity check will fail and the remediation will be aborted in order to preserve intentional changes. In this case, an informative message will be shown in the remediation report. If the system supports the `/etc/security/faillock.conf` file, the pam_faillock parameters should be defined in `faillock.conf` file.
Rationale: | By limiting the number of failed logon attempts the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_passwords_pam_faillock_unlock_time
References: |
cis-csc | 1, 12, 15, 16
cjis | 5.5.3
cobit5 | DSS05.04, DSS05.10, DSS06.10
cui | 3.1.8
isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9
iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3
nist | CM-6(a), AC-7(b)
nist-csf | PR.AC-7
ospp | FIA_AFL.1
pcidss | Req-8.1.7
os-srg | SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005
anssi | R31
cis | 4.5.2
ism | 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561
pcidss4 | 8.3.4, 8.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q pam; }; then

    var_accounts_passwords_pam_faillock_unlock_time='900'

    if [ -f /usr/bin/authselect ]; then
        if ! authselect check; then
    echo "
    authselect integrity check failed. Remediation aborted!
    This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
    It is not recommended to manually edit the PAM files when authselect tool is available.
    In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
    exit 1
    fi
    authselect enable-feature with-faillock

    authselect apply-changes -b
    else

    AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
    for pam_file in "${AUTH_FILES[@]}"
    do
        if ! grep -qE '^\s*auth\s+required\s+pam_faillock\.so\s+(preauth silent|authfail).*$' "$pam_file" ; then
            sed -i --follow-symlinks '/^auth.*sufficient.*pam_unix\.so.*/i auth        required      pam_faillock.so preauth silent' "$pam_file"
            sed -i --follow-symlinks '/^auth.*required.*pam_deny\.so.*/i auth        required      pam_faillock.so authfail' "$pam_file"
            sed -i --follow-symlinks '/^account.*required.*pam_unix\.so.*/i account     required      pam_faillock.so' "$pam_file"
        fi
        sed -Ei 's/(auth.*)(\[default=die\])(.*pam_faillock\.so)/\1required     \3/g' "$pam_file"
    done

    fi

    AUTH_FILES=("/etc/pam.d/system-auth" "/etc/pam.d/password-auth")
    SKIP_FAILLOCK_CHECK=false

    FAILLOCK_CONF="/etc/security/faillock.conf"
    if [ -f $FAILLOCK_CONF ] || [ "$SKIP_FAILLOCK_CHECK" = "true" ]; then
        regex="^\s*unlock_time\s*="
        line="unlock_time = $var_accounts_passwords_pam_faillock_unlock_time"
        if ! grep -q $regex $FAILLOCK_CONF; then
            echo $line >> $FAILLOCK_CONF
        else
            sed -i --follow-symlinks 's|^\s*\(unlock_time\s*=\s*\)\(\S\+\)|\1'"$var_accounts_passwords_pam_faillock_unlock_time"'|g' $FAILLOCK_CONF
        fi

        for pam_file in "${AUTH_FILES[@]}"
        do
            if [ -e "$pam_file" ] ; then
                PAM_FILE_PATH="$pam_file"
                if [ -f /usr/bin/authselect ]; then

                    if ! authselect check; then
                    echo "
                    authselect integrity check failed. Remediation aborted!
                    This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
                    It is not recommended to manually edit the PAM files when authselect tool is available.
                    In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
                    exit 1
                    fi

                    CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
                    # If not already in use, a custom profile is created preserving the enabled features.
                    if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                        ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                        # The "local" profile does not contain essential security features required by multiple Benchmarks.
                        # If currently used, it is replaced by "sssd", which is the best option in this case.
                        if [[ $CURRENT_PROFILE == local ]]; then
                            CURRENT_PROFILE="sssd"
                        fi
                        authselect create-profile hardening -b $CURRENT_PROFILE
                        CURRENT_PROFILE="custom/hardening"

                        authselect apply-changes -b --backup=before-hardening-custom-profile
                        authselect select $CURRENT_PROFILE
                        for feature in $ENABLED_FEATURES; do
                            authselect enable-feature $feature;
                        done

                        authselect apply-changes -b --backup=after-hardening-custom-profile
                    fi
                    PAM_FILE_NAME=$(basename "$pam_file")
                    PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

                    authselect apply-changes -b
                fi

            if grep -qP "^\s*auth\s.*\bpam_faillock.so\s.*\bunlock_time\b" "$PAM_FILE_PATH"; then
                sed -i -E --follow-symlinks "s/(.*auth.*pam_faillock.so.*)\bunlock_time\b=?[[:alnum:]]*(.*)/\1\2/g" "$PAM_FILE_PATH"
            fi
                if [ -f /usr/bin/authselect ]; then

                    authselect apply-changes -b
                fi
            else
                echo "$pam_file was not found" >&2
            fi
        done

    else
        for pam_file in "${AUTH_FILES[@]}"
        do
            if ! grep -qE '^\s*auth.*pam_faillock\.so\s+(preauth|authfail).*unlock_time' "$pam_file"; then
                sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*preauth.*/ s/$/ unlock_time='"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
                sed -i --follow-symlinks '/^auth.*required.*pam_faillock\.so.*authfail.*/ s/$/ unlock_time='"$var_accounts_passwords_pam_faillock_unlock_time"'/' "$pam_file"
            else
                sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*preauth.*\)\('"unlock_time"'=\)\S\+\b\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_unlock_time"'\3/' "$pam_file"
                sed -i --follow-symlinks 's/\(^auth.*required.*pam_faillock\.so.*authfail.*\)\('"unlock_time"'=\)\S\+\b\(.*\)/\1\2'"$var_accounts_passwords_pam_faillock_unlock_time"'\3/' "$pam_file"
            fi
        done
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.7
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_unlock_time
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set Lockout Time for Failed Password Attempts - Check if system relies on
        authselect tool
      ansible.builtin.stat:
        path: /usr/bin/authselect
      register: result_authselect_present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.7
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_unlock_time
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set Lockout Time for Failed Password Attempts - Remediation where authselect
        tool is present
      block:

      - name: Set Lockout Time for Failed Password Attempts - Check integrity of authselect
          current profile
        ansible.builtin.command:
          cmd: authselect check
        register: result_authselect_check_cmd
        changed_when: false
        check_mode: false
        failed_when: false

      - name: Set Lockout Time for Failed Password Attempts - Informative message based
          on the authselect integrity check result
        ansible.builtin.assert:
          that:
          - ansible_check_mode or result_authselect_check_cmd.rc == 0
          fail_msg:
          - authselect integrity check failed. Remediation aborted!
          - This remediation could not be applied because an authselect profile was not
            selected or the selected profile is not intact.
          - It is not recommended to manually edit the PAM files when authselect tool
            is available.
          - In cases where the default authselect profile does not cover a specific demand,
            a custom authselect profile is recommended.
          success_msg:
          - authselect integrity check passed

      - name: Set Lockout Time for Failed Password Attempts - Get authselect current features
        ansible.builtin.shell:
          cmd: authselect current | tail -n+3 | awk '{ print $2 }'
        register: result_authselect_features
        changed_when: false
        check_mode: false
        when:
        - result_authselect_check_cmd is success

      - name: Set Lockout Time for Failed Password Attempts - Ensure "with-faillock" feature
          is enabled using authselect tool
        ansible.builtin.command:
          cmd: authselect enable-feature with-faillock
        register: result_authselect_enable_feature_cmd
        when:
        - result_authselect_check_cmd is success
        - result_authselect_features.stdout is not search("with-faillock")

      - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_enable_feature_cmd is not skipped
        - result_authselect_enable_feature_cmd is success
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_authselect_present.stat.exists
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.7
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_unlock_time
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set Lockout Time for Failed Password Attempts - Remediation where authselect
        tool is not present
      block:

      - name: Set Lockout Time for Failed Password Attempts - Check if pam_faillock.so
          is already enabled
        ansible.builtin.lineinfile:
          path: /etc/pam.d/system-auth
          regexp: .*auth.*pam_faillock\.so (preauth|authfail)
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_faillock_is_enabled

      - name: Set Lockout Time for Failed Password Attempts - Enable pam_faillock.so preauth
          editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: auth        required      pam_faillock.so preauth
          insertbefore: ^auth.*sufficient.*pam_unix\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0

      - name: Set Lockout Time for Failed Password Attempts - Enable pam_faillock.so authfail
          editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: auth        required      pam_faillock.so authfail
          insertbefore: ^auth.*required.*pam_deny\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0

      - name: Set Lockout Time for Failed Password Attempts - Enable pam_faillock.so account
          section editing PAM files
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          line: account     required      pam_faillock.so
          insertbefore: ^account.*required.*pam_unix\.so.*
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_is_enabled.found == 0
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - not result_authselect_present.stat.exists
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.7
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_unlock_time
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_passwords_pam_faillock_unlock_time # promote to variable
      set_fact:
        var_accounts_passwords_pam_faillock_unlock_time: !!str 900
      tags:
        - always

    - name: Set Lockout Time for Failed Password Attempts - Check the presence of /etc/security/faillock.conf
        file
      ansible.builtin.stat:
        path: /etc/security/faillock.conf
      register: result_faillock_conf_check
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.7
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_unlock_time
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set Lockout Time for Failed Password Attempts - Ensure the pam_faillock.so
        unlock_time parameter in /etc/security/faillock.conf
      ansible.builtin.lineinfile:
        path: /etc/security/faillock.conf
        regexp: ^\s*unlock_time\s*=
        line: unlock_time = {{ var_accounts_passwords_pam_faillock_unlock_time }}
        state: present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_faillock_conf_check.stat.exists
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.7
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_unlock_time
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set Lockout Time for Failed Password Attempts - Ensure the pam_faillock.so
        unlock_time parameter not in PAM files
      block:

      - name: Set Lockout Time for Failed Password Attempts - Check if /etc/pam.d/system-auth
          file is present
        ansible.builtin.stat:
          path: /etc/pam.d/system-auth
        register: result_pam_auth_file_present

      - name: Set Lockout Time for Failed Password Attempts - Check the proper remediation
          for the system
        block:

        - name: Set Lockout Time for Failed Password Attempts - Define the PAM file to
            be edited as a local fact
          ansible.builtin.set_fact:
            pam_file_path: /etc/pam.d/system-auth

        - name: Set Lockout Time for Failed Password Attempts - Check if system relies
            on authselect tool
          ansible.builtin.stat:
            path: /usr/bin/authselect
          register: result_authselect_present

        - name: Set Lockout Time for Failed Password Attempts - Ensure authselect custom
            profile is used if authselect is present
          block:

          - name: Set Lockout Time for Failed Password Attempts - Check integrity of authselect
              current profile
            ansible.builtin.command:
              cmd: authselect check
            register: result_authselect_check_cmd
            changed_when: false
            check_mode: false
            failed_when: false

          - name: Set Lockout Time for Failed Password Attempts - Informative message
              based on the authselect integrity check result
            ansible.builtin.assert:
              that:
              - ansible_check_mode or result_authselect_check_cmd.rc == 0
              fail_msg:
              - authselect integrity check failed. Remediation aborted!
              - This remediation could not be applied because an authselect profile was
                not selected or the selected profile is not intact.
              - It is not recommended to manually edit the PAM files when authselect tool
                is available.
              - In cases where the default authselect profile does not cover a specific
                demand, a custom authselect profile is recommended.
              success_msg:
              - authselect integrity check passed

          - name: Set Lockout Time for Failed Password Attempts - Get authselect current
              profile
            ansible.builtin.shell:
              cmd: authselect current -r | awk '{ print $1 }'
            register: result_authselect_profile
            changed_when: false
            when:
            - result_authselect_check_cmd is success

          - name: Set Lockout Time for Failed Password Attempts - Define the current authselect
              profile as a local fact
            ansible.builtin.set_fact:
              authselect_current_profile: '{{ result_authselect_profile.stdout }}'
              authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
            when:
            - result_authselect_profile is not skipped
            - result_authselect_profile.stdout is match("custom/")

          - name: Set Lockout Time for Failed Password Attempts - Define the new authselect
              custom profile as a local fact
            ansible.builtin.set_fact:
              authselect_current_profile: '{{ result_authselect_profile.stdout }}'
              authselect_custom_profile: custom/hardening
            when:
            - result_authselect_profile is not skipped
            - result_authselect_profile.stdout is not match("custom/")

          - name: Set Lockout Time for Failed Password Attempts - Get authselect current
              features to also enable them in the custom profile
            ansible.builtin.shell:
              cmd: authselect current | tail -n+3 | awk '{ print $2 }'
            register: result_authselect_features
            changed_when: false
            check_mode: false
            when:
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")

          - name: Set Lockout Time for Failed Password Attempts - Check if any custom
              profile with the same name was already created
            ansible.builtin.stat:
              path: /etc/authselect/{{ authselect_custom_profile }}
            register: result_authselect_custom_profile_present
            changed_when: false
            when:
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")

          - name: Set Lockout Time for Failed Password Attempts - Create an authselect
              custom profile based on the current profile
            ansible.builtin.command:
              cmd: authselect create-profile hardening -b {{ authselect_current_profile
                }}
            when:
            - result_authselect_profile is not skipped
            - result_authselect_check_cmd is success
            - authselect_current_profile is not match("^(custom/|local)")
            - not result_authselect_custom_profile_present.stat.exists

          - name: Set Lockout Time for Failed Password Attempts - Create an authselect
              custom profile based on sssd profile
            ansible.builtin.command:
              cmd: authselect create-profile hardening -b sssd
            when:
            - result_authselect_profile is not skipped
            - result_authselect_check_cmd is success
            - authselect_current_profile is match("local")
            - not result_authselect_custom_profile_present.stat.exists

          - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
              are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")
            - authselect_custom_profile is not match(authselect_current_profile)

          - name: Set Lockout Time for Failed Password Attempts - Ensure the authselect
              custom profile is selected
            ansible.builtin.command:
              cmd: authselect select {{ authselect_custom_profile }}
            register: result_pam_authselect_select_profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")
            - authselect_custom_profile is not match(authselect_current_profile)

          - name: Set Lockout Time for Failed Password Attempts - Restore the authselect
              features in the custom profile
            ansible.builtin.command:
              cmd: authselect enable-feature {{ item }}
            loop: '{{ result_authselect_features.stdout_lines }}'
            register: result_pam_authselect_restore_features
            when:
            - result_authselect_profile is not skipped
            - result_authselect_features is not skipped
            - result_pam_authselect_select_profile is not skipped

          - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
              are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - result_pam_authselect_restore_features is not skipped

          - name: Set Lockout Time for Failed Password Attempts - Change the PAM file
              to be edited according to the custom authselect profile
            ansible.builtin.set_fact:
              pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
                | basename }}
            when:
            - authselect_custom_profile is defined
          when:
          - result_authselect_present.stat.exists

        - name: Set Lockout Time for Failed Password Attempts - Define a fact for control
            already filtered in case filters are used
          ansible.builtin.set_fact:
            pam_module_control: ''

        - name: Set Lockout Time for Failed Password Attempts - Check if {{ pam_file_path
            }} file is present
          ansible.builtin.stat:
            path: '{{ pam_file_path }}'
          register: result_pam_file_present

        - name: Set Lockout Time for Failed Password Attempts - Ensure the "unlock_time"
            option from "pam_faillock.so" is not present in {{ pam_file_path }}
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: (.*auth.*pam_faillock.so.*)\bunlock_time\b=?[0-9a-zA-Z]*(.*)
            replace: \1\2
          register: result_pam_option_removal
          when:
          - result_pam_file_present.stat.exists

        - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
            are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present.stat.exists
          - result_pam_option_removal is changed
        when:
        - result_pam_auth_file_present.stat.exists

      - name: Set Lockout Time for Failed Password Attempts - Check if /etc/pam.d/password-auth
          file is present
        ansible.builtin.stat:
          path: /etc/pam.d/password-auth
        register: result_pam_password_auth_file_present

      - name: Set Lockout Time for Failed Password Attempts - Check the proper remediation
          for the system
        block:

        - name: Set Lockout Time for Failed Password Attempts - Define the PAM file to
            be edited as a local fact
          ansible.builtin.set_fact:
            pam_file_path: /etc/pam.d/password-auth

        - name: Set Lockout Time for Failed Password Attempts - Check if system relies
            on authselect tool
          ansible.builtin.stat:
            path: /usr/bin/authselect
          register: result_authselect_present

        - name: Set Lockout Time for Failed Password Attempts - Ensure authselect custom
            profile is used if authselect is present
          block:

          - name: Set Lockout Time for Failed Password Attempts - Check integrity of authselect
              current profile
            ansible.builtin.command:
              cmd: authselect check
            register: result_authselect_check_cmd
            changed_when: false
            check_mode: false
            failed_when: false

          - name: Set Lockout Time for Failed Password Attempts - Informative message
              based on the authselect integrity check result
            ansible.builtin.assert:
              that:
              - ansible_check_mode or result_authselect_check_cmd.rc == 0
              fail_msg:
              - authselect integrity check failed. Remediation aborted!
              - This remediation could not be applied because an authselect profile was
                not selected or the selected profile is not intact.
              - It is not recommended to manually edit the PAM files when authselect tool
                is available.
              - In cases where the default authselect profile does not cover a specific
                demand, a custom authselect profile is recommended.
              success_msg:
              - authselect integrity check passed

          - name: Set Lockout Time for Failed Password Attempts - Get authselect current
              profile
            ansible.builtin.shell:
              cmd: authselect current -r | awk '{ print $1 }'
            register: result_authselect_profile
            changed_when: false
            when:
            - result_authselect_check_cmd is success

          - name: Set Lockout Time for Failed Password Attempts - Define the current authselect
              profile as a local fact
            ansible.builtin.set_fact:
              authselect_current_profile: '{{ result_authselect_profile.stdout }}'
              authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
            when:
            - result_authselect_profile is not skipped
            - result_authselect_profile.stdout is match("custom/")

          - name: Set Lockout Time for Failed Password Attempts - Define the new authselect
              custom profile as a local fact
            ansible.builtin.set_fact:
              authselect_current_profile: '{{ result_authselect_profile.stdout }}'
              authselect_custom_profile: custom/hardening
            when:
            - result_authselect_profile is not skipped
            - result_authselect_profile.stdout is not match("custom/")

          - name: Set Lockout Time for Failed Password Attempts - Get authselect current
              features to also enable them in the custom profile
            ansible.builtin.shell:
              cmd: authselect current | tail -n+3 | awk '{ print $2 }'
            register: result_authselect_features
            changed_when: false
            check_mode: false
            when:
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")

          - name: Set Lockout Time for Failed Password Attempts - Check if any custom
              profile with the same name was already created
            ansible.builtin.stat:
              path: /etc/authselect/{{ authselect_custom_profile }}
            register: result_authselect_custom_profile_present
            changed_when: false
            when:
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")

          - name: Set Lockout Time for Failed Password Attempts - Create an authselect
              custom profile based on the current profile
            ansible.builtin.command:
              cmd: authselect create-profile hardening -b {{ authselect_current_profile
                }}
            when:
            - result_authselect_profile is not skipped
            - result_authselect_check_cmd is success
            - authselect_current_profile is not match("^(custom/|local)")
            - not result_authselect_custom_profile_present.stat.exists

          - name: Set Lockout Time for Failed Password Attempts - Create an authselect
              custom profile based on sssd profile
            ansible.builtin.command:
              cmd: authselect create-profile hardening -b sssd
            when:
            - result_authselect_profile is not skipped
            - result_authselect_check_cmd is success
            - authselect_current_profile is match("local")
            - not result_authselect_custom_profile_present.stat.exists

          - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
              are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")
            - authselect_custom_profile is not match(authselect_current_profile)

          - name: Set Lockout Time for Failed Password Attempts - Ensure the authselect
              custom profile is selected
            ansible.builtin.command:
              cmd: authselect select {{ authselect_custom_profile }}
            register: result_pam_authselect_select_profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - authselect_current_profile is not match("custom/")
            - authselect_custom_profile is not match(authselect_current_profile)

          - name: Set Lockout Time for Failed Password Attempts - Restore the authselect
              features in the custom profile
            ansible.builtin.command:
              cmd: authselect enable-feature {{ item }}
            loop: '{{ result_authselect_features.stdout_lines }}'
            register: result_pam_authselect_restore_features
            when:
            - result_authselect_profile is not skipped
            - result_authselect_features is not skipped
            - result_pam_authselect_select_profile is not skipped

          - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
              are applied
            ansible.builtin.command:
              cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
            when:
            - result_authselect_check_cmd is success
            - result_authselect_profile is not skipped
            - result_pam_authselect_restore_features is not skipped

          - name: Set Lockout Time for Failed Password Attempts - Change the PAM file
              to be edited according to the custom authselect profile
            ansible.builtin.set_fact:
              pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
                | basename }}
            when:
            - authselect_custom_profile is defined
          when:
          - result_authselect_present.stat.exists

        - name: Set Lockout Time for Failed Password Attempts - Define a fact for control
            already filtered in case filters are used
          ansible.builtin.set_fact:
            pam_module_control: ''

        - name: Set Lockout Time for Failed Password Attempts - Check if {{ pam_file_path
            }} file is present
          ansible.builtin.stat:
            path: '{{ pam_file_path }}'
          register: result_pam_file_present

        - name: Set Lockout Time for Failed Password Attempts - Ensure the "unlock_time"
            option from "pam_faillock.so" is not present in {{ pam_file_path }}
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: (.*auth.*pam_faillock.so.*)\bunlock_time\b=?[0-9a-zA-Z]*(.*)
            replace: \1\2
          register: result_pam_option_removal
          when:
          - result_pam_file_present.stat.exists

        - name: Set Lockout Time for Failed Password Attempts - Ensure authselect changes
            are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present.stat.exists
          - result_pam_option_removal is changed
        when:
        - result_pam_password_auth_file_present.stat.exists
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_faillock_conf_check.stat.exists
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.7
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_unlock_time
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set Lockout Time for Failed Password Attempts - Ensure the pam_faillock.so
        unlock_time parameter in PAM files
      block:

      - name: Set Lockout Time for Failed Password Attempts - Check if pam_faillock.so
          unlock_time parameter is already enabled in pam files
        ansible.builtin.lineinfile:
          path: /etc/pam.d/system-auth
          regexp: .*auth.*pam_faillock\.so (preauth|authfail).*unlock_time
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_faillock_unlock_time_parameter_is_present

      - name: Set Lockout Time for Failed Password Attempts - Ensure the inclusion of
          pam_faillock.so preauth unlock_time parameter in auth section
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          backrefs: true
          regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)
          line: \1required\3 unlock_time={{ var_accounts_passwords_pam_faillock_unlock_time
            }}
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_unlock_time_parameter_is_present.found == 0

      - name: Set Lockout Time for Failed Password Attempts - Ensure the inclusion of
          pam_faillock.so authfail unlock_time parameter in auth section
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          backrefs: true
          regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)
          line: \1required\3 unlock_time={{ var_accounts_passwords_pam_faillock_unlock_time
            }}
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_unlock_time_parameter_is_present.found == 0

      - name: Set Lockout Time for Failed Password Attempts - Ensure the desired value
          for pam_faillock.so preauth unlock_time parameter in auth section
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          backrefs: true
          regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so preauth.*)(unlock_time)=[0-9]+(.*)
          line: \1required\3\4={{ var_accounts_passwords_pam_faillock_unlock_time }}\5
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_unlock_time_parameter_is_present.found > 0

      - name: Set Lockout Time for Failed Password Attempts - Ensure the desired value
          for pam_faillock.so authfail unlock_time parameter in auth section
        ansible.builtin.lineinfile:
          path: '{{ item }}'
          backrefs: true
          regexp: (^\s*auth\s+)([\w\[].*\b)(\s+pam_faillock.so authfail.*)(unlock_time)=[0-9]+(.*)
          line: \1required\3\4={{ var_accounts_passwords_pam_faillock_unlock_time }}\5
          state: present
        loop:
        - /etc/pam.d/system-auth
        - /etc/pam.d/password-auth
        when:
        - result_pam_faillock_unlock_time_parameter_is_present.found > 0
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - not result_faillock_conf_check.stat.exists
      tags:
      - CJIS-5.5.3
      - NIST-800-171-3.1.8
      - NIST-800-53-AC-7(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.1.7
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.4
      - accounts_passwords_pam_faillock_unlock_time
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
Group Set Password Quality Requirements Group contains 1 group and 3 rules
[ref] The default `pam_pwquality` PAM module provides strength checking for passwords. It performs a number of checks, such as making sure passwords are not similar to dictionary words, are of at least a certain length, are not the previous password reversed, and are not simply a change of case from the previous password. It can also require passwords to be in certain character classes. The `pam_pwquality` module is the preferred way of configuring password requirements. The man pages `pam_pwquality(8)` provide information on the capabilities and configuration of each.
Group Set Password Quality Requirements with pam_pwquality Group contains 3 rules
[ref] The `pam_pwquality` PAM module can be configured to meet requirements for a variety of policies. For example, to configure `pam_pwquality` to require at least one uppercase character, lowercase character, digit, and other (special) character, make sure that `pam_pwquality` exists in `/etc/pam.d/system-auth`:
    password    requisite     pam_pwquality.so try_first_pass local_users_only retry=3 authtok_type=
If no such line exists, add one as the first line of the password section in `/etc/pam.d/system-auth`. Next, modify the settings in `/etc/security/pwquality.conf` to match the following:
    difok = 4
    minlen = 14
    dcredit = -1
    ucredit = -1
    lcredit = -1
    ocredit = -1
    maxrepeat = 3
The arguments can be modified to ensure compliance with your organization's security policy. Discussion of each parameter follows.
#### Rule Ensure PAM Enforces Password Requirements - Minimum Different Categories [ref]
The pam_pwquality module's `minclass` parameter controls requirements for usage of different character classes, or types, of character that must exist in a password before it is considered valid. For example, setting this value to three (3) requires that any password must have characters from at least three different categories in order to be approved. The default value is zero (0), meaning there are no required classes. There are four categories available:
    * Upper-case characters
    * Lower-case characters
    * Digits
    * Special characters (for example, punctuation)
Modify the `minclass` setting in `/etc/security/pwquality.conf` entry to require 4 differing categories of characters when changing passwords.
Rationale: | Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised. Requiring a minimum number of character categories makes password guessing attacks more difficult by ensuring a larger search space.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_minclass
References: |
cis-csc | 1, 12, 15, 16, 5
cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1
iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nist | IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4)
nist-csf | PR.AC-1, PR.AC-6, PR.AC-7
os-srg | SRG-OS-000072-GPOS-00040
anssi | R68
cis | 4.5.1
ism | 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q libpwquality; }; then

    var_password_pam_minclass='4'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^minclass")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_minclass"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^minclass\\>" "/etc/security/pwquality.conf"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^minclass\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
    else
        if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
        fi
        printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - accounts_password_pam_minclass
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_password_pam_minclass # promote to variable
      set_fact:
        var_password_pam_minclass: !!str 4
      tags:
        - always

    - name: Ensure PAM Enforces Password Requirements - Minimum Different Categories -
        Ensure PAM variable minclass is set accordingly
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/security/pwquality.conf
        regexp: ^#?\s*minclass
        line: minclass = {{ var_password_pam_minclass }}
      when:
      - '"kernel" in ansible_facts.packages'
      - '"libpwquality" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - accounts_password_pam_minclass
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure PAM Enforces Password Requirements - Minimum Length [ref]
The pam_pwquality module's `minlen` parameter controls requirements for minimum characters required in a password. Add `minlen=14` after pam_pwquality to set minimum password length requirements.
Rationale: | The shorter the password, the lower the number of possible combinations that need to be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to exponentially increase the time and/or resources required to compromise the password.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_minlen
References: |
cis-csc | 1, 12, 15, 16, 5
cjis | 5.6.2.1.1
cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1
iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nist | IA-5(c), IA-5(1)(a), CM-6(a), IA-5(4)
nist-csf | PR.AC-1, PR.AC-6, PR.AC-7
ospp | FMT_SMF_EXT.1
pcidss | Req-8.2.3
os-srg | SRG-OS-000078-GPOS-00046
anssi | R31, R68
cis | 4.5.1
ism | 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561
pcidss4 | 8.3.6, 8.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q libpwquality; }; then

    var_password_pam_minlen='14'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^minlen")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_password_pam_minlen"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^minlen\\>" "/etc/security/pwquality.conf"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^minlen\\>.*/$escaped_formatted_output/gi" "/etc/security/pwquality.conf"
    else
        if [[ -s "/etc/security/pwquality.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/security/pwquality.conf" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/security/pwquality.conf"
        fi
        printf '%s\n' "$formatted_output" >> "/etc/security/pwquality.conf"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.3
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.6
      - accounts_password_pam_minlen
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_password_pam_minlen # promote to variable
      set_fact:
        var_password_pam_minlen: !!str 14
      tags:
        - always

    - name: Ensure PAM Enforces Password Requirements - Minimum Length - Ensure PAM variable
        minlen is set accordingly
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/security/pwquality.conf
        regexp: ^#?\s*minlen
        line: minlen = {{ var_password_pam_minlen }}
      when:
      - '"kernel" in ansible_facts.packages'
      - '"libpwquality" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(a)
      - NIST-800-53-IA-5(4)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.3
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.6
      - accounts_password_pam_minlen
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted Per-Session [ref]
To configure the number of retry prompts that are permitted per-session: Edit the `pam_pwquality.so` statement in `/etc/pam.d/system-auth` to show `retry=3` , or a lower value if site policy is more restrictive. The profile requirement is a maximum of `retry=3` prompts per session.
Rationale: | Setting the password retry prompts that are permitted on a per-session basis to a low value requires some software, such as SSH, to re-connect. This can slow down and draw additional attention to some types of password-guessing attacks. Note that this is different from account lockout, which is provided by the pam_faillock module.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_pam_retry
References: |
cis-csc | 1, 11, 12, 15, 16, 3, 5, 9
cjis | 5.5.3
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nist | CM-6(a), AC-7(a), IA-5(4)
nist-csf | PR.AC-1, PR.AC-6, PR.AC-7, PR.IP-1
os-srg | SRG-OS-000069-GPOS-00037, SRG-OS-000480-GPOS-00227
anssi | R68
cis | 4.5.1
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q libpwquality; }; then

    var_password_pam_retry='3'

    		if [ -e "/etc/pam.d/system-auth" ] ; then
        PAM_FILE_PATH="/etc/pam.d/system-auth"
        if [ -f /usr/bin/authselect ]; then

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                # The "local" profile does not contain essential security features required by multiple Benchmarks.
                # If currently used, it is replaced by "sssd", which is the best option in this case.
                if [[ $CURRENT_PROFILE == local ]]; then
                    CURRENT_PROFILE="sssd"
                fi
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "/etc/pam.d/system-auth")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
        fi

            if ! grep -qP "^\s*password\s+requisite\s+pam_pwquality.so\s*.*" "$PAM_FILE_PATH"; then
                # Line matching group + control + module was not found. Check group + module.
                if [ "$(grep -cP '^\s*password\s+.*\s+pam_pwquality.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                    # The control is updated only if one single line matches.
                    sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_pwquality.so.*)/\1requisite \2/" "$PAM_FILE_PATH"
                else
                    LAST_MATCH_LINE=$(grep -nP "^\s*account" "$PAM_FILE_PATH" | tail -n 1 | cut -d: -f 1)
                    if [ ! -z $LAST_MATCH_LINE ]; then
                        sed -i --follow-symlinks $LAST_MATCH_LINE" a password     requisite    pam_pwquality.so" "$PAM_FILE_PATH"
                    else
                        echo "password    requisite    pam_pwquality.so" >> "$PAM_FILE_PATH"
                    fi
                fi
            fi
            # Check the option
            if ! grep -qP "^\s*password\s+requisite\s+pam_pwquality.so\s*.*\sretry\b" "$PAM_FILE_PATH"; then
                sed -i -E --follow-symlinks "/\s*password\s+requisite\s+pam_pwquality.so.*/ s/$/ retry=$var_password_pam_retry/" "$PAM_FILE_PATH"
            else
                sed -i -E --follow-symlinks "s/(\s*password\s+requisite\s+pam_pwquality.so\s+.*)(retry=)[[:alnum:]]*\s*(.*)/\1\2$var_password_pam_retry \3/" "$PAM_FILE_PATH"
            fi
        if [ -f /usr/bin/authselect ]; then

            authselect apply-changes -b
        fi
    else
        echo "/etc/pam.d/system-auth was not found" >&2
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.3
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
    - name: XCCDF Value var_password_pam_retry # promote to variable
      set_fact:
        var_password_pam_retry: !!str 3
      tags:
        - always

    - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
        Per-Session - Define a fact for control already filtered in case filters are used
      ansible.builtin.set_fact:
        pam_module_control: requisite
      when:
      - '"kernel" in ansible_facts.packages'
      - '"libpwquality" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
        Per-Session - Check if expected PAM module line is present in /etc/pam.d/system-auth
      ansible.builtin.lineinfile:
        path: /etc/pam.d/system-auth
        regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwquality.so\s*.*
        state: absent
      check_mode: true
      changed_when: false
      register: result_pam_line_present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"libpwquality" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
        Per-Session - Include or update the PAM module line in /etc/pam.d/system-auth
      block:

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Check if required PAM module line is present in /etc/pam.d/system-auth
          with different control
        ansible.builtin.lineinfile:
          path: /etc/pam.d/system-auth
          regexp: ^\s*password\s+.*\s+pam_pwquality.so\s*
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_line_other_control_present

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Ensure the correct control for the required PAM module
          line in /etc/pam.d/system-auth
        ansible.builtin.replace:
          dest: /etc/pam.d/system-auth
          regexp: ^(\s*password\s+).*(\bpam_pwquality.so.*)
          replace: \1{{ pam_module_control }} \2
        register: result_pam_module_edit
        when:
        - result_pam_line_other_control_present.found == 1

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Ensure the required PAM module line is included in /etc/pam.d/system-auth
        ansible.builtin.lineinfile:
          dest: /etc/pam.d/system-auth
          insertafter: ^\s*account
          line: password    {{ pam_module_control }}    pam_pwquality.so
        register: result_pam_module_add
        when:
        - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
          > 1

      - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts
          Permitted Per-Session - Ensure authselect changes are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present is defined
        - result_authselect_present.stat.exists
        - |-
          (result_pam_module_add is defined and result_pam_module_add.changed)
           or (result_pam_module_edit is defined and result_pam_module_edit.changed)
      when:
      - '"kernel" in ansible_facts.packages'
      - '"libpwquality" in ansible_facts.packages'
      - result_pam_line_present.found is defined
      - result_pam_line_present.found == 0
      tags:
      - CJIS-5.5.3
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
        Per-Session - Define a fact for control already filtered in case filters are used
      ansible.builtin.set_fact:
        pam_module_control: requisite
      when:
      - '"kernel" in ansible_facts.packages'
      - '"libpwquality" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
        Per-Session - Check if the required PAM module option is present in /etc/pam.d/system-auth
      ansible.builtin.lineinfile:
        path: /etc/pam.d/system-auth
        regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwquality.so\s*.*\sretry\b
        state: absent
      check_mode: true
      changed_when: false
      register: result_pam_module_accounts_password_pam_retry_option_present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"libpwquality" in ansible_facts.packages'
      tags:
      - CJIS-5.5.3
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
        Per-Session - Ensure the "retry" PAM option for "pam_pwquality.so" is included
        in /etc/pam.d/system-auth
      ansible.builtin.lineinfile:
        path: /etc/pam.d/system-auth
        backrefs: true
        regexp: ^(\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwquality.so.*)
        line: \1 retry={{ var_password_pam_retry }}
        state: present
      register: result_pam_accounts_password_pam_retry_add
      when:
      - '"kernel" in ansible_facts.packages'
      - '"libpwquality" in ansible_facts.packages'
      - result_pam_module_accounts_password_pam_retry_option_present.found is defined
      - result_pam_module_accounts_password_pam_retry_option_present.found == 0
      tags:
      - CJIS-5.5.3
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure PAM Enforces Password Requirements - Authentication Retry Prompts Permitted
        Per-Session - Ensure the required value for "retry" PAM option from "pam_pwquality.so"
        in /etc/pam.d/system-auth
      ansible.builtin.lineinfile:
        path: /etc/pam.d/system-auth
        backrefs: true
        regexp: ^(\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_pwquality.so\s+.*)(retry)=[0-9a-zA-Z]*\s*(.*)
        line: \1\2={{ var_password_pam_retry }} \3
      register: result_pam_accounts_password_pam_retry_edit
      when:
      - '"kernel" in ansible_facts.packages'
      - '"libpwquality" in ansible_facts.packages'
      - result_pam_module_accounts_password_pam_retry_option_present.found > 0
      tags:
      - CJIS-5.5.3
      - NIST-800-53-AC-7(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(4)
      - accounts_password_pam_retry
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
Group Set Password Hashing Algorithm Group contains 3 rules
[ref] The system's default algorithm for storing password hashes in `/etc/shadow` is SHA-512. This can be configured in several locations.
#### Rule Set Password Hashing Algorithm in /etc/login.defs [ref]
In `/etc/login.defs`, add or update the following line to ensure the system will use SHA512 as the hashing algorithm:
    ENCRYPT_METHOD SHA512
Rationale: | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text. Using a stronger hashing algorithm makes password cracking attacks more difficult.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_logindefs
References: |
cis-csc | 1, 12, 15, 16, 5
cjis | 5.6.2.2
cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.13.11
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1
iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nist | IA-5(c), IA-5(1)(c), CM-6(a)
nist-csf | PR.AC-1, PR.AC-6, PR.AC-7
pcidss | Req-8.2.1
os-srg | SRG-OS-000073-GPOS-00041
cis | 4.5.4
ism | 0418, 1055, 1402
pcidss4 | 8.3.2, 8.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q shadow-utils; }; then

    var_password_hashing_algorithm='SHA512'

    # Allow multiple algorithms, but choose the first one for remediation
    #
    var_password_hashing_algorithm="$(echo $var_password_hashing_algorithm | cut -d \| -f 1)"

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^ENCRYPT_METHOD")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s %s" "$stripped_key" "$var_password_hashing_algorithm"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^ENCRYPT_METHOD\\>" "/etc/login.defs"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^ENCRYPT_METHOD\\>.*/$escaped_formatted_output/gi" "/etc/login.defs"
    else
        if [[ -s "/etc/login.defs" ]] && [[ -n "$(tail -c 1 -- "/etc/login.defs" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/login.defs"
        fi
        printf '%s\n' "$formatted_output" >> "/etc/login.defs"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.2
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - set_password_hashing_algorithm_logindefs
    - name: XCCDF Value var_password_hashing_algorithm # promote to variable
      set_fact:
        var_password_hashing_algorithm: !!str SHA512
      tags:
        - always

    - name: Set Password Hashing Algorithm in /etc/login.defs
      ansible.builtin.lineinfile:
        dest: /etc/login.defs
        regexp: ^#?ENCRYPT_METHOD
        line: ENCRYPT_METHOD {{ var_password_hashing_algorithm.split('|')[0] }}
        state: present
        create: true
      when:
      - '"kernel" in ansible_facts.packages'
      - '"shadow-utils" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.2
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - set_password_hashing_algorithm_logindefs
#### Rule Set PAM Password Hashing Algorithm - password-auth [ref]
The PAM system service can be configured to only store encrypted representations of passwords. In `/etc/pam.d/password-auth`, the `password` section of the file controls which PAM modules to execute during a password change. Set the `pam_unix.so` module in the `password` section to include the option `sha512` and no other hashing algorithms as shown below:
    password    sufficient    pam_unix.so sha512
              other arguments...
This will help ensure that new passwords for local users will be stored using the sha512 algorithm. Warning: The hashing algorithms to be used with pam_unix.so are defined with independent module options. There are at least 7 possible algorithms and likely more algorithms will be introduced along the time. Due the the number of options and its possible combinations, the use of multiple hashing algorithm options may bring unexpected behaviors to the system. For this reason the check will pass only when one hashing algorithm option is defined and is aligned to the "var_password_hashing_algorithm_pam" variable. The remediation will ensure the correct option and remove any other extra hashing algorithm option.
Rationale: | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text. This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the `crypt_style` configuration option in `/etc/libuser.conf` ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_passwordauth
References: |
cis-csc | 1, 12, 15, 16, 5
cjis | 5.6.2.2
cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.13.11
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1
iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nist | IA-5(c), IA-5(1)(c), CM-6(a)
nist-csf | PR.AC-1, PR.AC-6, PR.AC-7
pcidss | Req-8.2.1
os-srg | SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061
cis | 4.5.4
ism | 0418, 1055, 1402
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q pam; }; then

    var_password_hashing_algorithm_pam='sha512'

    # Allow multiple algorithms, but choose the first one for remediation
    var_password_hashing_algorithm_pam="$(echo $var_password_hashing_algorithm_pam | cut -d \| -f 1)"

    PAM_FILE_PATH="/etc/pam.d/password-auth"

    if [ -e "$PAM_FILE_PATH" ] ; then
        PAM_FILE_PATH="$PAM_FILE_PATH"
        if [ -f /usr/bin/authselect ]; then

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                # The "local" profile does not contain essential security features required by multiple Benchmarks.
                # If currently used, it is replaced by "sssd", which is the best option in this case.
                if [[ $CURRENT_PROFILE == local ]]; then
                    CURRENT_PROFILE="sssd"
                fi
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "$PAM_FILE_PATH")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
        fi

            if ! grep -qP "^\s*password\s+sufficient\s+pam_unix.so\s*.*" "$PAM_FILE_PATH"; then
                # Line matching group + control + module was not found. Check group + module.
                if [ "$(grep -cP '^\s*password\s+.*\s+pam_unix.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                    # The control is updated only if one single line matches.
                    sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_unix.so.*)/\1sufficient \2/" "$PAM_FILE_PATH"
                else
                    echo "password    sufficient    pam_unix.so" >> "$PAM_FILE_PATH"
                fi
            fi
            # Check the option
            if ! grep -qP "^\s*password\s+sufficient\s+pam_unix.so\s*.*\s$var_password_hashing_algorithm_pam\b" "$PAM_FILE_PATH"; then
                sed -i -E --follow-symlinks "/\s*password\s+sufficient\s+pam_unix.so.*/ s/$/ $var_password_hashing_algorithm_pam/" "$PAM_FILE_PATH"
            fi
        if [ -f /usr/bin/authselect ]; then

            authselect apply-changes -b
        fi
    else
        echo "$PAM_FILE_PATH was not found" >&2
    fi

    # Ensure only the correct hashing algorithm option is used.
    declare -a HASHING_ALGORITHMS_OPTIONS=("sha512" "yescrypt" "gost_yescrypt" "blowfish" "sha256" "md5" "bigcrypt")

    for hash_option in "${HASHING_ALGORITHMS_OPTIONS[@]}"; do
      if [ "$hash_option" != "$var_password_hashing_algorithm_pam" ]; then
        if grep -qP "^\s*password\s+.*\s+pam_unix.so\s+.*\b$hash_option\b" "$PAM_FILE_PATH"; then
          if [ -e "$PAM_FILE_PATH" ] ; then
        PAM_FILE_PATH="$PAM_FILE_PATH"
        if [ -f /usr/bin/authselect ]; then

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                # The "local" profile does not contain essential security features required by multiple Benchmarks.
                # If currently used, it is replaced by "sssd", which is the best option in this case.
                if [[ $CURRENT_PROFILE == local ]]; then
                    CURRENT_PROFILE="sssd"
                fi
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "$PAM_FILE_PATH")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
        fi

    if grep -qP "^\s*password\s+.*\s+pam_unix.so\s.*\b$hash_option\b" "$PAM_FILE_PATH"; then
        sed -i -E --follow-symlinks "s/(.*password.*.*.*pam_unix.so.*)\b$hash_option\b=?[[:alnum:]]*(.*)/\1\2/g" "$PAM_FILE_PATH"
    fi
        if [ -f /usr/bin/authselect ]; then

            authselect apply-changes -b
        fi
    else
        echo "$PAM_FILE_PATH was not found" >&2
    fi
        fi
      fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_passwordauth
    - name: XCCDF Value var_password_hashing_algorithm_pam # promote to variable
      set_fact:
        var_password_hashing_algorithm_pam: !!str sha512
      tags:
        - always

    - name: Set PAM Password Hashing Algorithm - password-auth - Check if /etc/pam.d/password-auth
        file is present
      ansible.builtin.stat:
        path: /etc/pam.d/password-auth
      register: result_pam_password_auth_file_present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_passwordauth

    - name: Set PAM Password Hashing Algorithm - password-auth - Check the proper remediation
        for the system
      block:

      - name: Set PAM Password Hashing Algorithm - password-auth - Define the PAM file
          to be edited as a local fact
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/password-auth

      - name: Set PAM Password Hashing Algorithm - password-auth - Check if system relies
          on authselect tool
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: Set PAM Password Hashing Algorithm - password-auth - Ensure authselect custom
          profile is used if authselect is present
        block:

        - name: Set PAM Password Hashing Algorithm - password-auth - Check integrity of
            authselect current profile
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          check_mode: false
          failed_when: false

        - name: Set PAM Password Hashing Algorithm - password-auth - Informative message
            based on the authselect integrity check result
          ansible.builtin.assert:
            that:
            - ansible_check_mode or result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: Set PAM Password Hashing Algorithm - password-auth - Get authselect current
            profile
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: Set PAM Password Hashing Algorithm - password-auth - Define the current
            authselect profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: Set PAM Password Hashing Algorithm - password-auth - Define the new authselect
            custom profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: Set PAM Password Hashing Algorithm - password-auth - Get authselect current
            features to also enable them in the custom profile
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          check_mode: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Set PAM Password Hashing Algorithm - password-auth - Check if any custom
            profile with the same name was already created
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Set PAM Password Hashing Algorithm - password-auth - Create an authselect
            custom profile based on the current profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("^(custom/|local)")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Set PAM Password Hashing Algorithm - password-auth - Create an authselect
            custom profile based on sssd profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b sssd
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is match("local")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Set PAM Password Hashing Algorithm - password-auth - Ensure authselect
            changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Set PAM Password Hashing Algorithm - password-auth - Ensure the authselect
            custom profile is selected
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Set PAM Password Hashing Algorithm - password-auth - Restore the authselect
            features in the custom profile
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: Set PAM Password Hashing Algorithm - password-auth - Ensure authselect
            changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: Set PAM Password Hashing Algorithm - password-auth - Change the PAM file
            to be edited according to the custom authselect profile
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
          when:
          - authselect_custom_profile is defined
        when:
        - result_authselect_present.stat.exists

      - name: Set PAM Password Hashing Algorithm - password-auth - Define a fact for control
          already filtered in case filters are used
        ansible.builtin.set_fact:
          pam_module_control: sufficient

      - name: Set PAM Password Hashing Algorithm - password-auth - Check if expected PAM
          module line is present in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_unix.so\s*.*
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_line_present

      - name: Set PAM Password Hashing Algorithm - password-auth - Include or update the
          PAM module line in {{ pam_file_path }}
        block:

        - name: Set PAM Password Hashing Algorithm - password-auth - Check if required
            PAM module line is present in {{ pam_file_path }} with different control
          ansible.builtin.lineinfile:
            path: '{{ pam_file_path }}'
            regexp: ^\s*password\s+.*\s+pam_unix.so\s*
            state: absent
          check_mode: true
          changed_when: false
          register: result_pam_line_other_control_present

        - name: Set PAM Password Hashing Algorithm - password-auth - Ensure the correct
            control for the required PAM module line in {{ pam_file_path }}
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: ^(\s*password\s+).*(\bpam_unix.so.*)
            replace: \1{{ pam_module_control }} \2
          register: result_pam_module_edit
          when:
          - result_pam_line_other_control_present.found == 1

        - name: Set PAM Password Hashing Algorithm - password-auth - Ensure the required
            PAM module line is included in {{ pam_file_path }}
          ansible.builtin.lineinfile:
            dest: '{{ pam_file_path }}'
            line: password    {{ pam_module_control }}    pam_unix.so
          register: result_pam_module_add
          when:
          - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
            > 1

        - name: Set PAM Password Hashing Algorithm - password-auth - Ensure authselect
            changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present is defined
          - result_authselect_present.stat.exists
          - |-
            (result_pam_module_add is defined and result_pam_module_add.changed)
             or (result_pam_module_edit is defined and result_pam_module_edit.changed)
        when:
        - result_pam_line_present.found is defined
        - result_pam_line_present.found == 0

      - name: Set PAM Password Hashing Algorithm - password-auth - Define a fact for control
          already filtered in case filters are used
        ansible.builtin.set_fact:
          pam_module_control: sufficient

      - name: Set PAM Password Hashing Algorithm - password-auth - Check if the required
          PAM module option is present in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_unix.so\s*.*\s{{
            var_password_hashing_algorithm_pam.split("|")[0] }}\b
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_module_set_password_hashing_algorithm_passwordauth_option_present

      - name: Set PAM Password Hashing Algorithm - password-auth - Ensure the "{{ var_password_hashing_algorithm_pam.split("|")[0]
          }}" PAM option for "pam_unix.so" is included in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          backrefs: true
          regexp: ^(\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_unix.so.*)
          line: \1 {{ var_password_hashing_algorithm_pam.split("|")[0] }}
          state: present
        register: result_pam_set_password_hashing_algorithm_passwordauth_add
        when:
        - result_pam_module_set_password_hashing_algorithm_passwordauth_option_present.found
          is defined
        - result_pam_module_set_password_hashing_algorithm_passwordauth_option_present.found
          == 0

      - name: Set PAM Password Hashing Algorithm - password-auth - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present.stat.exists
        - |-
          (result_pam_set_password_hashing_algorithm_passwordauth_add is defined and result_pam_set_password_hashing_algorithm_passwordauth_add.changed)
           or (result_pam_set_password_hashing_algorithm_passwordauth_edit is defined and result_pam_set_password_hashing_algorithm_passwordauth_edit.changed)
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_pam_password_auth_file_present.stat.exists
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_passwordauth

    - name: Set PAM Password Hashing Algorithm - password-auth - Check if /etc/pam.d/password-auth
        File is Present
      ansible.builtin.stat:
        path: /etc/pam.d/password-auth
      register: result_pam_password_auth_file_present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_passwordauth

    - name: Set PAM Password Hashing Algorithm - password-auth - Check The Proper Remediation
        For The System
      block:

      - name: Set PAM Password Hashing Algorithm - password-auth - Define the PAM file
          to be edited as a local fact
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/password-auth

      - name: Set PAM Password Hashing Algorithm - password-auth - Check if system relies
          on authselect tool
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: Set PAM Password Hashing Algorithm - password-auth - Ensure authselect custom
          profile is used if authselect is present
        block:

        - name: Set PAM Password Hashing Algorithm - password-auth - Check integrity of
            authselect current profile
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          check_mode: false
          failed_when: false

        - name: Set PAM Password Hashing Algorithm - password-auth - Informative message
            based on the authselect integrity check result
          ansible.builtin.assert:
            that:
            - ansible_check_mode or result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: Set PAM Password Hashing Algorithm - password-auth - Get authselect current
            profile
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: Set PAM Password Hashing Algorithm - password-auth - Define the current
            authselect profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: Set PAM Password Hashing Algorithm - password-auth - Define the new authselect
            custom profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: Set PAM Password Hashing Algorithm - password-auth - Get authselect current
            features to also enable them in the custom profile
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          check_mode: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Set PAM Password Hashing Algorithm - password-auth - Check if any custom
            profile with the same name was already created
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Set PAM Password Hashing Algorithm - password-auth - Create an authselect
            custom profile based on the current profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("^(custom/|local)")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Set PAM Password Hashing Algorithm - password-auth - Create an authselect
            custom profile based on sssd profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b sssd
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is match("local")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Set PAM Password Hashing Algorithm - password-auth - Ensure authselect
            changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Set PAM Password Hashing Algorithm - password-auth - Ensure the authselect
            custom profile is selected
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Set PAM Password Hashing Algorithm - password-auth - Restore the authselect
            features in the custom profile
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: Set PAM Password Hashing Algorithm - password-auth - Ensure authselect
            changes are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: Set PAM Password Hashing Algorithm - password-auth - Change the PAM file
            to be edited according to the custom authselect profile
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
          when:
          - authselect_custom_profile is defined
        when:
        - result_authselect_present.stat.exists

      - name: Set PAM Password Hashing Algorithm - password-auth - Check if "{{ pam_file_path
          }}" File is Present
        ansible.builtin.stat:
          path: '{{ pam_file_path }}'
        register: pam_file_path_present

      - name: Set PAM Password Hashing Algorithm - password-auth - Ensure That Only the
          Correct Hashing Algorithm Option For pam_unix.so Is Used in {{ pam_file_path
          }}
        ansible.builtin.replace:
          dest: '{{ pam_file_path }}'
          regexp: (^\s*password.*pam_unix\.so.*)\b{{ item }}\b\s*(.*)
          replace: \1\2
        when:
        - item != var_password_hashing_algorithm_pam.split('|')[0]
        - pam_file_path_present.stat.exists
        loop:
        - sha512
        - yescrypt
        - gost_yescrypt
        - blowfish
        - sha256
        - md5
        - bigcrypt
        register: result_pam_hashing_options_removal

      - name: Set PAM Password Hashing Algorithm - password-auth - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present.stat.exists
        - result_pam_hashing_options_removal is changed
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_pam_password_auth_file_present.stat.exists
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_passwordauth
#### Rule Set PAM Password Hashing Algorithm - system-auth [ref]
The PAM system service can be configured to only store encrypted representations of passwords. In "/etc/pam.d/system-auth", the `password` section of the file controls which PAM modules to execute during a password change. Set the `pam_unix.so` module in the `password` section to include the option `sha512` and no other hashing algorithms as shown below:
    password    sufficient    pam_unix.so sha512
              other arguments...
This will help ensure that new passwords for local users will be stored using the sha512 algorithm. Warning: The hashing algorithms to be used with pam_unix.so are defined with independent module options. There are at least 7 possible algorithms and likely more algorithms will be introduced along the time. Due the the number of options and its possible combinations, the use of multiple hashing algorithm options may bring unexpected behaviors to the system. For this reason the check will pass only when one hashing algorithm option is defined and is aligned to the "var_password_hashing_algorithm_pam" variable. The remediation will ensure the correct option and remove any other extra hashing algorithm option.
Rationale: | Passwords need to be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text. This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the `crypt_style` configuration option in `/etc/libuser.conf` ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_set_password_hashing_algorithm_systemauth
References: |
cis-csc | 1, 12, 15, 16, 5
cjis | 5.6.2.2
cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.13.11
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1
iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nist | IA-5(c), IA-5(1)(c), CM-6(a)
nist-csf | PR.AC-1, PR.AC-6, PR.AC-7
pcidss | Req-8.2.1
os-srg | SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061
anssi | R68
cis | 4.5.4
ism | 0418, 1055, 1402
pcidss4 | 8.3.2, 8.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q pam; }; then

    var_password_hashing_algorithm_pam='sha512'

    # Allow multiple algorithms, but choose the first one for remediation
    var_password_hashing_algorithm_pam="$(echo $var_password_hashing_algorithm_pam | cut -d \| -f 1)"

    PAM_FILE_PATH="/etc/pam.d/system-auth"

    # Ensure all the hashing algorithm option is removed.
    declare -a HASHING_ALGORITHMS_OPTIONS=("sha512" "yescrypt" "gost_yescrypt" "blowfish" "sha256" "md5" "bigcrypt")

    for hash_option in "${HASHING_ALGORITHMS_OPTIONS[@]}"; do
      if grep -qP "^\s*password\s+.*\s+pam_unix.so\s+.*\b$hash_option\b" "$PAM_FILE_PATH"; then
        if [ -e "$PAM_FILE_PATH" ] ; then
        PAM_FILE_PATH="$PAM_FILE_PATH"
        if [ -f /usr/bin/authselect ]; then

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                # The "local" profile does not contain essential security features required by multiple Benchmarks.
                # If currently used, it is replaced by "sssd", which is the best option in this case.
                if [[ $CURRENT_PROFILE == local ]]; then
                    CURRENT_PROFILE="sssd"
                fi
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "$PAM_FILE_PATH")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
        fi

    if grep -qP "^\s*password\s+.*\s+pam_unix.so\s.*\b$hash_option\b" "$PAM_FILE_PATH"; then
        sed -i -E --follow-symlinks "s/(.*password.*.*.*pam_unix.so.*)\b$hash_option\b=?[[:alnum:]]*(.*)/\1\2/g" "$PAM_FILE_PATH"
    fi
        if [ -f /usr/bin/authselect ]; then

            authselect apply-changes -b
        fi
    else
        echo "$PAM_FILE_PATH was not found" >&2
    fi
      fi
    done

    if [ -e "$PAM_FILE_PATH" ] ; then
        PAM_FILE_PATH="$PAM_FILE_PATH"
        if [ -f /usr/bin/authselect ]; then

            if ! authselect check; then
            echo "
            authselect integrity check failed. Remediation aborted!
            This remediation could not be applied because an authselect profile was not selected or the selected profile is not intact.
            It is not recommended to manually edit the PAM files when authselect tool is available.
            In cases where the default authselect profile does not cover a specific demand, a custom authselect profile is recommended."
            exit 1
            fi

            CURRENT_PROFILE=$(authselect current -r | awk '{ print $1 }')
            # If not already in use, a custom profile is created preserving the enabled features.
            if [[ ! $CURRENT_PROFILE == custom/* ]]; then
                ENABLED_FEATURES=$(authselect current | tail -n+3 | awk '{ print $2 }')
                # The "local" profile does not contain essential security features required by multiple Benchmarks.
                # If currently used, it is replaced by "sssd", which is the best option in this case.
                if [[ $CURRENT_PROFILE == local ]]; then
                    CURRENT_PROFILE="sssd"
                fi
                authselect create-profile hardening -b $CURRENT_PROFILE
                CURRENT_PROFILE="custom/hardening"

                authselect apply-changes -b --backup=before-hardening-custom-profile
                authselect select $CURRENT_PROFILE
                for feature in $ENABLED_FEATURES; do
                    authselect enable-feature $feature;
                done

                authselect apply-changes -b --backup=after-hardening-custom-profile
            fi
            PAM_FILE_NAME=$(basename "$PAM_FILE_PATH")
            PAM_FILE_PATH="/etc/authselect/$CURRENT_PROFILE/$PAM_FILE_NAME"

            authselect apply-changes -b
        fi

            if ! grep -qP "^\s*password\s+sufficient\s+pam_unix.so\s*.*" "$PAM_FILE_PATH"; then
                # Line matching group + control + module was not found. Check group + module.
                if [ "$(grep -cP '^\s*password\s+.*\s+pam_unix.so\s*' "$PAM_FILE_PATH")" -eq 1 ]; then
                    # The control is updated only if one single line matches.
                    sed -i -E --follow-symlinks "s/^(\s*password\s+).*(\bpam_unix.so.*)/\1sufficient \2/" "$PAM_FILE_PATH"
                else
                    echo "password    sufficient    pam_unix.so" >> "$PAM_FILE_PATH"
                fi
            fi
            # Check the option
            if ! grep -qP "^\s*password\s+sufficient\s+pam_unix.so\s*.*\s$var_password_hashing_algorithm_pam\b" "$PAM_FILE_PATH"; then
                sed -i -E --follow-symlinks "/\s*password\s+sufficient\s+pam_unix.so.*/ s/$/ $var_password_hashing_algorithm_pam/" "$PAM_FILE_PATH"
            fi
        if [ -f /usr/bin/authselect ]; then

            authselect apply-changes -b
        fi
    else
        echo "$PAM_FILE_PATH was not found" >&2
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_systemauth
    - name: XCCDF Value var_password_hashing_algorithm_pam # promote to variable
      set_fact:
        var_password_hashing_algorithm_pam: !!str sha512
      tags:
        - always

    - name: Set PAM Password Hashing Algorithm - system-auth - Check if /etc/pam.d/system-auth
        file is present
      ansible.builtin.stat:
        path: /etc/pam.d/system-auth
      register: result_pam_auth_file_present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_systemauth

    - name: Set PAM Password Hashing Algorithm - system-auth - Check the proper remediation
        for the system
      block:

      - name: Set PAM Password Hashing Algorithm - system-auth - Define the PAM file to
          be edited as a local fact
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/system-auth

      - name: Set PAM Password Hashing Algorithm - system-auth - Check if system relies
          on authselect tool
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: Set PAM Password Hashing Algorithm - system-auth - Ensure authselect custom
          profile is used if authselect is present
        block:

        - name: Set PAM Password Hashing Algorithm - system-auth - Check integrity of
            authselect current profile
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          check_mode: false
          failed_when: false

        - name: Set PAM Password Hashing Algorithm - system-auth - Informative message
            based on the authselect integrity check result
          ansible.builtin.assert:
            that:
            - ansible_check_mode or result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: Set PAM Password Hashing Algorithm - system-auth - Get authselect current
            profile
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: Set PAM Password Hashing Algorithm - system-auth - Define the current
            authselect profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: Set PAM Password Hashing Algorithm - system-auth - Define the new authselect
            custom profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: Set PAM Password Hashing Algorithm - system-auth - Get authselect current
            features to also enable them in the custom profile
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          check_mode: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Set PAM Password Hashing Algorithm - system-auth - Check if any custom
            profile with the same name was already created
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Set PAM Password Hashing Algorithm - system-auth - Create an authselect
            custom profile based on the current profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("^(custom/|local)")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Set PAM Password Hashing Algorithm - system-auth - Create an authselect
            custom profile based on sssd profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b sssd
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is match("local")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Set PAM Password Hashing Algorithm - system-auth - Ensure authselect changes
            are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Set PAM Password Hashing Algorithm - system-auth - Ensure the authselect
            custom profile is selected
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Set PAM Password Hashing Algorithm - system-auth - Restore the authselect
            features in the custom profile
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: Set PAM Password Hashing Algorithm - system-auth - Ensure authselect changes
            are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: Set PAM Password Hashing Algorithm - system-auth - Change the PAM file
            to be edited according to the custom authselect profile
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
          when:
          - authselect_custom_profile is defined
        when:
        - result_authselect_present.stat.exists

      - name: Set PAM Password Hashing Algorithm - system-auth - Define a fact for control
          already filtered in case filters are used
        ansible.builtin.set_fact:
          pam_module_control: sufficient

      - name: Set PAM Password Hashing Algorithm - system-auth - Check if expected PAM
          module line is present in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_unix.so\s*.*
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_line_present

      - name: Set PAM Password Hashing Algorithm - system-auth - Include or update the
          PAM module line in {{ pam_file_path }}
        block:

        - name: Set PAM Password Hashing Algorithm - system-auth - Check if required PAM
            module line is present in {{ pam_file_path }} with different control
          ansible.builtin.lineinfile:
            path: '{{ pam_file_path }}'
            regexp: ^\s*password\s+.*\s+pam_unix.so\s*
            state: absent
          check_mode: true
          changed_when: false
          register: result_pam_line_other_control_present

        - name: Set PAM Password Hashing Algorithm - system-auth - Ensure the correct
            control for the required PAM module line in {{ pam_file_path }}
          ansible.builtin.replace:
            dest: '{{ pam_file_path }}'
            regexp: ^(\s*password\s+).*(\bpam_unix.so.*)
            replace: \1{{ pam_module_control }} \2
          register: result_pam_module_edit
          when:
          - result_pam_line_other_control_present.found == 1

        - name: Set PAM Password Hashing Algorithm - system-auth - Ensure the required
            PAM module line is included in {{ pam_file_path }}
          ansible.builtin.lineinfile:
            dest: '{{ pam_file_path }}'
            line: password    {{ pam_module_control }}    pam_unix.so
          register: result_pam_module_add
          when:
          - result_pam_line_other_control_present.found == 0 or result_pam_line_other_control_present.found
            > 1

        - name: Set PAM Password Hashing Algorithm - system-auth - Ensure authselect changes
            are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b
          when:
          - result_authselect_present is defined
          - result_authselect_present.stat.exists
          - |-
            (result_pam_module_add is defined and result_pam_module_add.changed)
             or (result_pam_module_edit is defined and result_pam_module_edit.changed)
        when:
        - result_pam_line_present.found is defined
        - result_pam_line_present.found == 0

      - name: Set PAM Password Hashing Algorithm - system-auth - Define a fact for control
          already filtered in case filters are used
        ansible.builtin.set_fact:
          pam_module_control: sufficient

      - name: Set PAM Password Hashing Algorithm - system-auth - Check if the required
          PAM module option is present in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          regexp: ^\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_unix.so\s*.*\s{{
            var_password_hashing_algorithm_pam.split("|")[0] }}\b
          state: absent
        check_mode: true
        changed_when: false
        register: result_pam_module_set_password_hashing_algorithm_systemauth_option_present

      - name: Set PAM Password Hashing Algorithm - system-auth - Ensure the "{{ var_password_hashing_algorithm_pam.split("|")[0]
          }}" PAM option for "pam_unix.so" is included in {{ pam_file_path }}
        ansible.builtin.lineinfile:
          path: '{{ pam_file_path }}'
          backrefs: true
          regexp: ^(\s*password\s+{{ pam_module_control | regex_escape() }}\s+pam_unix.so.*)
          line: \1 {{ var_password_hashing_algorithm_pam.split("|")[0] }}
          state: present
        register: result_pam_set_password_hashing_algorithm_systemauth_add
        when:
        - result_pam_module_set_password_hashing_algorithm_systemauth_option_present.found
          is defined
        - result_pam_module_set_password_hashing_algorithm_systemauth_option_present.found
          == 0

      - name: Set PAM Password Hashing Algorithm - system-auth - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present.stat.exists
        - |-
          (result_pam_set_password_hashing_algorithm_systemauth_add is defined and result_pam_set_password_hashing_algorithm_systemauth_add.changed)
           or (result_pam_set_password_hashing_algorithm_systemauth_edit is defined and result_pam_set_password_hashing_algorithm_systemauth_edit.changed)
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_pam_auth_file_present.stat.exists
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_systemauth

    - name: Set PAM Password Hashing Algorithm - system-auth - Check if /etc/pam.d/system-auth
        File is Present
      ansible.builtin.stat:
        path: /etc/pam.d/system-auth
      register: result_pam_auth_file_present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_systemauth

    - name: Set PAM Password Hashing Algorithm - system-auth - Check The Proper Remediation
        For The System
      block:

      - name: Set PAM Password Hashing Algorithm - system-auth - Define the PAM file to
          be edited as a local fact
        ansible.builtin.set_fact:
          pam_file_path: /etc/pam.d/system-auth

      - name: Set PAM Password Hashing Algorithm - system-auth - Check if system relies
          on authselect tool
        ansible.builtin.stat:
          path: /usr/bin/authselect
        register: result_authselect_present

      - name: Set PAM Password Hashing Algorithm - system-auth - Ensure authselect custom
          profile is used if authselect is present
        block:

        - name: Set PAM Password Hashing Algorithm - system-auth - Check integrity of
            authselect current profile
          ansible.builtin.command:
            cmd: authselect check
          register: result_authselect_check_cmd
          changed_when: false
          check_mode: false
          failed_when: false

        - name: Set PAM Password Hashing Algorithm - system-auth - Informative message
            based on the authselect integrity check result
          ansible.builtin.assert:
            that:
            - ansible_check_mode or result_authselect_check_cmd.rc == 0
            fail_msg:
            - authselect integrity check failed. Remediation aborted!
            - This remediation could not be applied because an authselect profile was
              not selected or the selected profile is not intact.
            - It is not recommended to manually edit the PAM files when authselect tool
              is available.
            - In cases where the default authselect profile does not cover a specific
              demand, a custom authselect profile is recommended.
            success_msg:
            - authselect integrity check passed

        - name: Set PAM Password Hashing Algorithm - system-auth - Get authselect current
            profile
          ansible.builtin.shell:
            cmd: authselect current -r | awk '{ print $1 }'
          register: result_authselect_profile
          changed_when: false
          when:
          - result_authselect_check_cmd is success

        - name: Set PAM Password Hashing Algorithm - system-auth - Define the current
            authselect profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: '{{ result_authselect_profile.stdout }}'
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is match("custom/")

        - name: Set PAM Password Hashing Algorithm - system-auth - Define the new authselect
            custom profile as a local fact
          ansible.builtin.set_fact:
            authselect_current_profile: '{{ result_authselect_profile.stdout }}'
            authselect_custom_profile: custom/hardening
          when:
          - result_authselect_profile is not skipped
          - result_authselect_profile.stdout is not match("custom/")

        - name: Set PAM Password Hashing Algorithm - system-auth - Get authselect current
            features to also enable them in the custom profile
          ansible.builtin.shell:
            cmd: authselect current | tail -n+3 | awk '{ print $2 }'
          register: result_authselect_features
          changed_when: false
          check_mode: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Set PAM Password Hashing Algorithm - system-auth - Check if any custom
            profile with the same name was already created
          ansible.builtin.stat:
            path: /etc/authselect/{{ authselect_custom_profile }}
          register: result_authselect_custom_profile_present
          changed_when: false
          when:
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")

        - name: Set PAM Password Hashing Algorithm - system-auth - Create an authselect
            custom profile based on the current profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b {{ authselect_current_profile
              }}
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is not match("^(custom/|local)")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Set PAM Password Hashing Algorithm - system-auth - Create an authselect
            custom profile based on sssd profile
          ansible.builtin.command:
            cmd: authselect create-profile hardening -b sssd
          when:
          - result_authselect_profile is not skipped
          - result_authselect_check_cmd is success
          - authselect_current_profile is match("local")
          - not result_authselect_custom_profile_present.stat.exists

        - name: Set PAM Password Hashing Algorithm - system-auth - Ensure authselect changes
            are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=before-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Set PAM Password Hashing Algorithm - system-auth - Ensure the authselect
            custom profile is selected
          ansible.builtin.command:
            cmd: authselect select {{ authselect_custom_profile }}
          register: result_pam_authselect_select_profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - authselect_current_profile is not match("custom/")
          - authselect_custom_profile is not match(authselect_current_profile)

        - name: Set PAM Password Hashing Algorithm - system-auth - Restore the authselect
            features in the custom profile
          ansible.builtin.command:
            cmd: authselect enable-feature {{ item }}
          loop: '{{ result_authselect_features.stdout_lines }}'
          register: result_pam_authselect_restore_features
          when:
          - result_authselect_profile is not skipped
          - result_authselect_features is not skipped
          - result_pam_authselect_select_profile is not skipped

        - name: Set PAM Password Hashing Algorithm - system-auth - Ensure authselect changes
            are applied
          ansible.builtin.command:
            cmd: authselect apply-changes -b --backup=after-hardening-custom-profile
          when:
          - result_authselect_check_cmd is success
          - result_authselect_profile is not skipped
          - result_pam_authselect_restore_features is not skipped

        - name: Set PAM Password Hashing Algorithm - system-auth - Change the PAM file
            to be edited according to the custom authselect profile
          ansible.builtin.set_fact:
            pam_file_path: /etc/authselect/{{ authselect_custom_profile }}/{{ pam_file_path
              | basename }}
          when:
          - authselect_custom_profile is defined
        when:
        - result_authselect_present.stat.exists

      - name: Set PAM Password Hashing Algorithm - system-auth - Check if "{{ pam_file_path
          }}" File is Present
        ansible.builtin.stat:
          path: '{{ pam_file_path }}'
        register: pam_file_path_present

      - name: Set PAM Password Hashing Algorithm - system-auth - Ensure That Only the
          Correct Hashing Algorithm Option For pam_unix.so Is Used in {{ pam_file_path
          }}
        ansible.builtin.replace:
          dest: '{{ pam_file_path }}'
          regexp: (^\s*password.*pam_unix\.so.*)\b{{ item }}\b\s*(.*)
          replace: \1\2
        when:
        - item != var_password_hashing_algorithm_pam.split('|')[0]
        - pam_file_path_present.stat.exists
        loop:
        - sha512
        - yescrypt
        - gost_yescrypt
        - blowfish
        - sha256
        - md5
        - bigcrypt
        register: result_pam_hashing_options_removal

      - name: Set PAM Password Hashing Algorithm - system-auth - Ensure authselect changes
          are applied
        ansible.builtin.command:
          cmd: authselect apply-changes -b
        when:
        - result_authselect_present.stat.exists
        - result_pam_hashing_options_removal is changed
      when:
      - '"kernel" in ansible_facts.packages'
      - '"pam" in ansible_facts.packages'
      - result_pam_auth_file_present.stat.exists
      tags:
      - CJIS-5.6.2.2
      - NIST-800-171-3.13.11
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(c)
      - PCI-DSS-Req-8.2.1
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - set_password_hashing_algorithm_systemauth
Group Protect Accounts by Restricting Password-Based Login Group contains 4 groups and 24 rules
[ref] Conventionally, Unix shell accounts are accessed by providing a username and password to a login program, which tests these values for correctness using the `/etc/passwd` and `/etc/shadow` files. Password-based login is vulnerable to guessing of weak passwords, and to sniffing and man-in-the-middle attacks against passwords entered over a network or at an insecure console. Therefore, mechanisms for accessing accounts by entering usernames and passwords should be restricted to those which are operationally necessary.
Group Set Account Expiration Parameters Group contains 2 rules
[ref] Accounts can be configured to be automatically disabled after a certain time period, meaning that they will require administrator interaction to become usable again. Expiration of accounts after inactivity can be set for all accounts by default and also on a per-account basis, such as for accounts that are known to be temporary. To configure automatic expiration of an account following the expiration of its password (that is, after the password has expired and not been changed), run the following command, substituting `NUM_DAYS` and `USER` appropriately:
    $ sudo chage -I NUM_DAYS USER
Accounts, such as temporary accounts, can also be configured to expire on an explicitly-set date with the `-E` option. The file `/etc/default/useradd` controls default settings for all newly-created accounts created with the system's normal command line utilities. Warning: This will only apply to newly created accounts
#### Rule Set Account Expiration Following Inactivity [ref]
To specify the number of days after a password expires (which signifies inactivity) until an account is permanently disabled, add or correct the following line in `/etc/default/useradd`:
    INACTIVE=30
If a password is currently on the verge of expiration, then `30` day(s) remain(s) until the account is automatically disabled. However, if the password will not expire for another 60 days, then 60 days plus `30` day(s) could elapse until the account would be automatically disabled. See the `useradd` man page for more information.
Rationale: | Inactive identifiers pose a risk to systems and applications because attackers may exploit an inactive identifier and potentially obtain undetected access to the system. Disabling inactive accounts ensures that accounts which may not have been responsibly removed are not available to attackers who may have compromised their credentials. Owners of inactive accounts will not notice if unauthorized access to their user account has been obtained.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_account_disable_post_pw_expiration
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8
cjis | 5.6.2.1.1
cobit5 | DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.5.6
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2
iso27001-2013 | A.12.4.1, A.12.4.3, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nerc-cip | CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3
nist | IA-4(e), AC-2(3), CM-6(a)
nist-csf | DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7
pcidss | Req-8.1.4
os-srg | SRG-OS-000118-GPOS-00060
cis | 4.6.1.4
pcidss4 | 8.2.6, 8.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q shadow-utils; }; then

    var_account_disable_post_pw_expiration='30'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^INACTIVE")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s=%s" "$stripped_key" "$var_account_disable_post_pw_expiration"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^INACTIVE\\>" "/etc/default/useradd"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^INACTIVE\\>.*/$escaped_formatted_output/gi" "/etc/default/useradd"
    else
        if [[ -s "/etc/default/useradd" ]] && [[ -n "$(tail -c 1 -- "/etc/default/useradd" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/default/useradd"
        fi
        printf '%s\n' "$formatted_output" >> "/etc/default/useradd"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.6
      - NIST-800-53-AC-2(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-4(e)
      - PCI-DSS-Req-8.1.4
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.6
      - account_disable_post_pw_expiration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_account_disable_post_pw_expiration # promote to variable
      set_fact:
        var_account_disable_post_pw_expiration: !!str 30
      tags:
        - always

    - name: Set Account Expiration Following Inactivity
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/default/useradd
        regexp: ^INACTIVE
        line: INACTIVE={{ var_account_disable_post_pw_expiration }}
      when:
      - '"kernel" in ansible_facts.packages'
      - '"shadow-utils" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.6
      - NIST-800-53-AC-2(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-4(e)
      - PCI-DSS-Req-8.1.4
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.6
      - account_disable_post_pw_expiration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure All Accounts on the System Have Unique Names [ref]
Ensure accounts on the system have unique names. To ensure all accounts have unique names, run the following command:
    $ sudo getent passwd | awk -F: '{ print $1}' | uniq -d
If a username is returned, change or delete the username.
Rationale: | Unique usernames allow for accountability on the system.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_account_unique_name
References: |
cjis | 5.5.2
pcidss | Req-8.1.1
cis | 6.2.6
pcidss4 | 8.2.1, 8.2
Group Set Password Expiration Parameters Group contains 7 rules
[ref] The file `/etc/login.defs` controls several password-related settings. Programs such as `passwd`, `su`, and `login` consult `/etc/login.defs` to determine behavior with regard to password aging, expiration warnings, and length. See the man page `login.defs(5)` for more information. Users should be forced to change their passwords, in order to decrease the utility of compromised passwords. However, the need to change passwords often should be balanced against the risk that users will reuse or write down passwords if forced to change them too often. Forcing password changes every 90-360 days, depending on the environment, is recommended. Set the appropriate value as `PASS_MAX_DAYS` and apply it to existing accounts with the `-M` flag. The `PASS_MIN_DAYS` (`-m`) setting prevents password changes for 7 days after the first change, to discourage password cycling. If you use this setting, train users to contact an administrator for an emergency password change in case a new password becomes compromised. The `PASS_WARN_AGE` (`-W`) setting gives users 7 days of warnings at login time that their passwords are about to expire. For example, for each existing human user USER, expiration parameters could be adjusted to a 180 day maximum password age, 7 day minimum password age, and 7 day warning period with the following command:
    $ sudo chage -M 180 -m 7 -W 7 USER
#### Rule Set Password Maximum Age [ref]
To specify password maximum age for new accounts, edit the file `/etc/login.defs` and add or correct the following line:
    PASS_MAX_DAYS 365
The profile requirement is `365`.
Rationale: | Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised. Setting the password maximum age ensures users are required to periodically change their passwords. Requiring shorter password lifetimes increases the risk of users writing down the password in a convenient location subject to physical compromise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_maximum_age_login_defs
References: |
cis-csc | 1, 12, 15, 16, 5
cjis | 5.6.2.1
cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.5.6
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1
iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nist | IA-5(f), IA-5(1)(d), CM-6(a)
nist-csf | PR.AC-1, PR.AC-6, PR.AC-7
pcidss | Req-8.2.4
os-srg | SRG-OS-000076-GPOS-00044
cis | 4.6.1.1
ism | 0418, 1055, 1402
pcidss4 | 8.3.9, 8.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q shadow-utils; }; then

    var_accounts_maximum_age_login_defs='365'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^PASS_MAX_DAYS")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s %s" "$stripped_key" "$var_accounts_maximum_age_login_defs"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^PASS_MAX_DAYS\\>" "/etc/login.defs"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^PASS_MAX_DAYS\\>.*/$escaped_formatted_output/gi" "/etc/login.defs"
    else
        if [[ -s "/etc/login.defs" ]] && [[ -n "$(tail -c 1 -- "/etc/login.defs" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/login.defs"
        fi
        printf '%s\n' "$formatted_output" >> "/etc/login.defs"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.1
      - NIST-800-171-3.5.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.4
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.9
      - accounts_maximum_age_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_maximum_age_login_defs # promote to variable
      set_fact:
        var_accounts_maximum_age_login_defs: !!str 365
      tags:
        - always

    - name: Set Password Maximum Age
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/login.defs
        regexp: ^#?PASS_MAX_DAYS
        line: PASS_MAX_DAYS {{ var_accounts_maximum_age_login_defs }}
      when:
      - '"kernel" in ansible_facts.packages'
      - '"shadow-utils" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.1
      - NIST-800-171-3.5.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.4
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.9
      - accounts_maximum_age_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Set Password Minimum Age [ref]
To specify password minimum age for new accounts, edit the file `/etc/login.defs` and add or correct the following line:
    PASS_MIN_DAYS 1
A value of 1 day is considered sufficient for many environments. The profile requirement is `1`.
Rationale: | Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, then the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse. Setting the minimum password age protects against users cycling back to a favorite password after satisfying the password reuse requirement.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_minimum_age_login_defs
References: |
cis-csc | 1, 12, 15, 16, 5
cjis | 5.6.2.1.1
cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.5.8
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1
iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nist | IA-5(f), IA-5(1)(d), CM-6(a)
nist-csf | PR.AC-1, PR.AC-6, PR.AC-7
os-srg | SRG-OS-000075-GPOS-00043
cis | 4.6.1.2
ism | 0418, 1055, 1402
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q shadow-utils; }; then

    var_accounts_minimum_age_login_defs='1'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^PASS_MIN_DAYS")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s %s" "$stripped_key" "$var_accounts_minimum_age_login_defs"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^PASS_MIN_DAYS\\>" "/etc/login.defs"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^PASS_MIN_DAYS\\>.*/$escaped_formatted_output/gi" "/etc/login.defs"
    else
        if [[ -s "/etc/login.defs" ]] && [[ -n "$(tail -c 1 -- "/etc/login.defs" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/login.defs"
        fi
        printf '%s\n' "$formatted_output" >> "/etc/login.defs"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - accounts_minimum_age_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_minimum_age_login_defs # promote to variable
      set_fact:
        var_accounts_minimum_age_login_defs: !!str 1
      tags:
        - always

    - name: Set Password Minimum Age
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/login.defs
        regexp: ^#?PASS_MIN_DAYS
        line: PASS_MIN_DAYS {{ var_accounts_minimum_age_login_defs }}
      when:
      - '"kernel" in ansible_facts.packages'
      - '"shadow-utils" in ansible_facts.packages'
      tags:
      - CJIS-5.6.2.1.1
      - NIST-800-171-3.5.8
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - accounts_minimum_age_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Set Existing Passwords Maximum Age [ref]
Configure non-compliant accounts to enforce a 365-day maximum password lifetime restriction by running the following command:
    $ sudo chage -M 365
              USER
Rationale: | Any password, no matter how complex, can eventually be cracked. Therefore, passwords need to be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_set_max_life_existing
References: |
nist | IA-5(f), IA-5(1)(d), CM-6(a)
os-srg | SRG-OS-000076-GPOS-00044
cis | 4.6.1.1
pcidss4 | 8.3.9, 8.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    var_accounts_maximum_age_login_defs='365'

    while IFS= read -r i; do

        chage -M $var_accounts_maximum_age_login_defs $i

    done <   <(awk -v var="$var_accounts_maximum_age_login_defs" -F: '(/^[^:]+:[^!*]/ && ($5 > var || $5 == "")) {print $1}' /etc/shadow)

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.9
      - accounts_password_set_max_life_existing
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_maximum_age_login_defs # promote to variable
      set_fact:
        var_accounts_maximum_age_login_defs: !!str 365
      tags:
        - always

    - name: Collect users with not correct maximum time period between password changes
      ansible.builtin.command:
        cmd: awk -F':' '(/^[^:]+:[^!*]/ && ($5 > {{ var_accounts_maximum_age_login_defs
          }} || $5 == "")) {print $1}' /etc/shadow
      register: user_names
      changed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.9
      - accounts_password_set_max_life_existing
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Change the maximum time period between password changes
      ansible.builtin.user:
        user: '{{ item }}'
        password_expire_max: '{{ var_accounts_maximum_age_login_defs }}'
      with_items: '{{ user_names.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - user_names.stdout_lines | length > 0
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.9
      - accounts_password_set_max_life_existing
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Set Existing Passwords Minimum Age [ref]
Configure non-compliant accounts to enforce a 24 hours/1 day minimum password lifetime by running the following command:
    $ sudo chage -m 1 USER
Rationale: | Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_set_min_life_existing
References: |
nist | IA-5(f), IA-5(1)(d), CM-6(a)
os-srg | SRG-OS-000075-GPOS-00043
cis | 4.6.1.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    var_accounts_minimum_age_login_defs='1'

    while IFS= read -r i; do

        chage -m $var_accounts_minimum_age_login_defs $i

    done <   <(awk -v var="$var_accounts_minimum_age_login_defs" -F: '(/^[^:]+:[^!*]/ && ($4 < var || $4 == "")) {print $1}' /etc/shadow)

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - accounts_password_set_min_life_existing
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_minimum_age_login_defs # promote to variable
      set_fact:
        var_accounts_minimum_age_login_defs: !!str 1
      tags:
        - always

    - name: Collect users with not correct minimum time period between password changes
      ansible.builtin.command: |
        awk -F':' '(/^[^:]+:[^!*]/ && ($4 < {{ var_accounts_minimum_age_login_defs }} || $4 == "")) {print $1}' /etc/shadow
      register: user_names
      changed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - accounts_password_set_min_life_existing
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Change the minimum time period between password changes
      ansible.builtin.command: |
        chage -m {{ var_accounts_minimum_age_login_defs }} {{ item }}
      with_items: '{{ user_names.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - user_names.stdout_lines | length > 0
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - accounts_password_set_min_life_existing
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Set Existing Passwords Warning Age [ref]
To configure how many days prior to password expiration that a warning will be issued to users, run the command:
    $ sudo chage --warndays 7
              USER
This profile requirement is `7`.
Rationale: | Providing an advance warning that a password will be expiring gives users time to think of a secure password. Users caught unaware may choose a simple password or write it down where it may be discovered.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_set_warn_age_existing
References: |
nist | IA-5(f), IA-5(1)(d), CM-6(a)
cis | 4.6.1.3
pcidss4 | 8.3.9, 8.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    var_accounts_password_warn_age_login_defs='7'

    while IFS= read -r i; do
        chage --warndays $var_accounts_password_warn_age_login_defs $i
    done <   <(awk -v var="$var_accounts_password_warn_age_login_defs" -F: '(($6 < var || $6 == "") && $2 ~ /^\$/) {print $1}' /etc/shadow)

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.9
      - accounts_password_set_warn_age_existing
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
    - name: XCCDF Value var_accounts_password_warn_age_login_defs # promote to variable
      set_fact:
        var_accounts_password_warn_age_login_defs: !!str 7
      tags:
        - always

    - name: Set Existing Passwords Warning Age - Collect Users With Incorrect Number of
        Days of Warning Before Password Expires
      ansible.builtin.command:
        cmd: awk -F':' '(($6 < {{ var_accounts_password_warn_age_login_defs }} || $6 ==
          "") && $2 ~ /^\$/) {print $1}' /etc/shadow
      register: result_pass_warn_age_user_names
      changed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.9
      - accounts_password_set_warn_age_existing
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set Existing Passwords Warning Age - Ensure the Number of Days of Warning
        Before Password Expires
      ansible.builtin.command:
        cmd: chage --warndays {{ var_accounts_password_warn_age_login_defs }} {{ item
          }}
      with_items: '{{ result_pass_warn_age_user_names.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - result_pass_warn_age_user_names is not skipped and result_pass_warn_age_user_names.stdout_lines
        | length > 0
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.9
      - accounts_password_set_warn_age_existing
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Set Password Warning Age [ref]
To specify how many days prior to password expiration that a warning will be issued to users, edit the file `/etc/login.defs` and add or correct the following line:
    PASS_WARN_AGE 7
The profile requirement is `7`.
Rationale: | Setting the password warning age enables users to make the change at a practical time.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_warn_age_login_defs
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8
cobit5 | DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.5.8
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2
iso27001-2013 | A.12.4.1, A.12.4.3, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nist | IA-5(f), IA-5(1)(d), CM-6(a)
nist-csf | DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7
pcidss | Req-8.2.4
cis | 4.6.1.3
ism | 0418, 1055, 1402
pcidss4 | 8.3.9, 8.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q shadow-utils; }; then

    var_accounts_password_warn_age_login_defs='7'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^PASS_WARN_AGE")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s %s" "$stripped_key" "$var_accounts_password_warn_age_login_defs"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^PASS_WARN_AGE\\>" "/etc/login.defs"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^PASS_WARN_AGE\\>.*/$escaped_formatted_output/gi" "/etc/login.defs"
    else
        if [[ -s "/etc/login.defs" ]] && [[ -n "$(tail -c 1 -- "/etc/login.defs" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/login.defs"
        fi
        printf '%s\n' "$formatted_output" >> "/etc/login.defs"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.5.8
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.4
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.9
      - accounts_password_warn_age_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_password_warn_age_login_defs # promote to variable
      set_fact:
        var_accounts_password_warn_age_login_defs: !!str 7
      tags:
        - always

    - name: Set Password Warning Age
      ansible.builtin.lineinfile:
        dest: /etc/login.defs
        regexp: ^PASS_WARN_AGE *[0-9]*
        state: present
        line: PASS_WARN_AGE        {{ var_accounts_password_warn_age_login_defs }}
        create: true
      when:
      - '"kernel" in ansible_facts.packages'
      - '"shadow-utils" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.5.8
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)(d)
      - NIST-800-53-IA-5(f)
      - PCI-DSS-Req-8.2.4
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.9
      - accounts_password_warn_age_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Set existing passwords a period of inactivity before they been locked [ref]
Configure user accounts that have been inactive for over a given period of time to be automatically disabled by running the following command:
    $ sudo chage --inactive 30 USER
Rationale: | Inactive accounts pose a threat to system security since the users are not logging in to notice failed login attempts or other anomalies.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_set_post_pw_existing
References: |
cobit5 | DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.5.6
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2
iso27001-2013 | A.12.4.1, A.12.4.3, A.18.1.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nerc-cip | CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3
nist | IA-4(e), AC-2(3), CM-6(a)
nist-csf | DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7
pcidss | Req-8.1.4
os-srg | SRG-OS-000118-GPOS-00060
cis | 4.6.1.4
pcidss4 | 8.2.6, 8.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    var_account_disable_post_pw_expiration='30'

    while IFS= read -r i; do
        chage --inactive $var_account_disable_post_pw_expiration $i
    done <   <(awk -v var="$var_account_disable_post_pw_expiration" -F: '(($7 > var || $7 == "") && $2 ~ /^\$/) {print $1}' /etc/shadow)

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.5.6
      - NIST-800-53-AC-2(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-4(e)
      - PCI-DSS-Req-8.1.4
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.6
      - accounts_set_post_pw_existing
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_account_disable_post_pw_expiration # promote to variable
      set_fact:
        var_account_disable_post_pw_expiration: !!str 30
      tags:
        - always

    - name: Collect users with not correct INACTIVE parameter set
      ansible.builtin.command:
        cmd: awk -F':' '(($7 > {{ var_account_disable_post_pw_expiration }} || $7 == "")
          && $2 ~ /^\$/) {print $1}' /etc/shadow
      register: user_names
      changed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.5.6
      - NIST-800-53-AC-2(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-4(e)
      - PCI-DSS-Req-8.1.4
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.6
      - accounts_set_post_pw_existing
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Change the period of inactivity
      ansible.builtin.command:
        cmd: chage --inactive {{ var_account_disable_post_pw_expiration }} {{ item }}
      with_items: '{{ user_names.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - user_names is not skipped and user_names.stdout_lines | length > 0
      tags:
      - NIST-800-171-3.5.6
      - NIST-800-53-AC-2(3)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-4(e)
      - PCI-DSS-Req-8.1.4
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.6
      - accounts_set_post_pw_existing
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
Group Verify Proper Storage and Existence of Password Hashes Group contains 5 rules
[ref] By default, password hashes for local accounts are stored in the second field (colon-separated) in `/etc/shadow`. This file should be readable only by processes running with root credentials, preventing users from casually accessing others' password hashes and attempting to crack them. However, it remains possible to misconfigure the system and store password hashes in world-readable files such as `/etc/passwd`, or to even store passwords themselves in plaintext on the system. Using system-provided tools for password change/creation should allow administrators to avoid such misconfiguration.
#### Rule Verify All Account Password Hashes are Shadowed [ref]
If any password hashes are stored in `/etc/passwd` (in the second field, instead of an `x` or `*`), the cause of this misconfiguration should be investigated. The account should have its password reset and the hash should be properly stored, or the account should be deleted entirely.
Rationale: | The hashes for all user account passwords should be stored in the file `/etc/shadow` and never in `/etc/passwd`, which is readable by all users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_all_shadowed
References: |
cis-csc | 1, 12, 15, 16, 5
cjis | 5.5.2
cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.5.10
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1
iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nist | IA-5(h), CM-6(a)
nist-csf | PR.AC-1, PR.AC-6, PR.AC-7
pcidss | Req-8.2.1
cis | 6.2.1
ism | 1402
pcidss4 | 8.3.2, 8.3
#### Rule Ensure all users last password change date is in the past [ref]
All users should have a password change date in the past. Warning: Automatic remediation is not available, in order to avoid any system disruption.
Rationale: | If a user recorded password change date is in the future then they could bypass any set password expiration.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_password_last_change_is_in_past
References: |
cis | 4.6.1.5
pcidss4 | 8.3.5, 8.3
#### Rule All GIDs referenced in /etc/passwd must be defined in /etc/group [ref]
Add a group to the system for each GID referenced without a corresponding group.
Rationale: | If a user is assigned the Group Identifier (GID) of a group not existing on the system, and a group with the Group Identifier (GID) is subsequently created, the user may have unintended rights to any files associated with the group.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_gid_passwd_group_same
References: |
cis-csc | 1, 12, 15, 16, 5
cjis | 5.5.2
cobit5 | DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1
iso27001-2013 | A.18.1.4, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nist | IA-2, CM-6(a)
nist-csf | PR.AC-1, PR.AC-6, PR.AC-7
pcidss | Req-8.5.a
os-srg | SRG-OS-000104-GPOS-00051
cis | 6.2.3
pcidss4 | 8.2.2, 8.2
#### Rule Ensure There Are No Accounts With Blank or Null Passwords [ref]
Check the "/etc/shadow" file for blank passwords with the following command:
    $ sudo awk -F: '!$2 {print $1}' /etc/shadow
If the command returns any results, this is a finding. Configure all accounts on the system to have a password or lock the account with the following commands: Perform a password reset:
    $ sudo passwd [username]
Lock an account:
    $ sudo passwd -l [username]
Warning: Note that this rule is not applicable for systems running within a container. Having user with empty password within a container is not considered a risk, because it should not be possible to directly login into a container anyway.
Rationale: | If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_no_empty_passwords_etc_shadow
References: |
nist | CM-6(b), CM-6.1(iv)
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.6.6, 6.2.2
pcidss4 | 2.2.2, 2.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    readarray -t users_with_empty_pass < <(awk -F: '!$2 {print $1}' /etc/shadow)

    for user_with_empty_pass in "${users_with_empty_pass[@]}"
    do
        passwd -l $user_with_empty_pass
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.2
      - high_severity
      - low_complexity
      - low_disruption
      - no_empty_passwords_etc_shadow
      - no_reboot_needed
      - restrict_strategy

    - name: Collect users with no password
      ansible.builtin.command: |
        awk -F: '!$2 {print $1}' /etc/shadow
      register: users_nopasswd
      changed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.2
      - high_severity
      - low_complexity
      - low_disruption
      - no_empty_passwords_etc_shadow
      - no_reboot_needed
      - restrict_strategy

    - name: Lock users with no password
      ansible.builtin.command: |
        passwd -l {{ item }}
      with_items: '{{ users_nopasswd.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - users_nopasswd is not skipped and users_nopasswd.stdout_lines | length > 0
      tags:
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.2
      - high_severity
      - low_complexity
      - low_disruption
      - no_empty_passwords_etc_shadow
      - no_reboot_needed
      - restrict_strategy
#### Rule Verify No .forward Files Exist [ref]
The `.forward` file specifies an email address to forward the user's mail to.
Rationale: | Use of the `.forward` file poses a security risk in that sensitive data may be inadvertently transferred outside the organization. The .forward file also poses a risk as it can be used to execute commands that may perform unintended actions.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_no_forward_files
References: |
cis | 6.2.11
Group Restrict Root Logins Group contains 7 rules
[ref] Direct root logins should be allowed only for emergency use. In normal situations, the administrator should access the system via a unique unprivileged account, and then use `su` or `sudo` to execute privileged commands. Discouraging administrators from accessing the root account directly ensures an audit trail in organizations with multiple administrators. Locking down the channels through which root can connect directly also reduces opportunities for password-guessing against the root account. The `login` program uses the file `/etc/securetty` to determine which interfaces should allow root logins. The virtual devices `/dev/console` and `/dev/tty*` represent the system consoles (accessible via the Ctrl-Alt-F1 through Ctrl-Alt-F6 keyboard sequences on a default installation). The default securetty file also contains `/dev/vc/*`. These are likely to be deprecated in most environments, but may be retained for compatibility. Root should also be prohibited from connecting via network protocols. Other sections of this document include guidance describing how to prevent root from logging in via SSH.
#### Rule Verify Only Root Has UID 0 [ref]
If any account other than root has a UID of 0, this misconfiguration should be investigated and the accounts other than root should be removed or have their UID changed. If the account is associated with system commands or applications the UID should be changed to one greater than "0" but less than "1000." Otherwise assign a UID greater than "1000" that has not already been assigned.
Rationale: | An account has root authority if it has a UID of 0. Multiple accounts with a UID of 0 afford more opportunity for potential intruders to guess a password for a privileged account. Proper configuration of sudo is recommended to afford multiple system administrators access to root privileges in an accountable manner.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_no_uid_except_zero
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.10
cui | 3.1.1, 3.1.5
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nist | IA-2, AC-6(5), IA-4(b)
nist-csf | PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5
pcidss | Req-8.5
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.2.9
ism | 1546
pcidss4 | 8.2.1, 8.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    awk -F: '$3 == 0 && $1 != "root" { print $1 }' /etc/passwd | xargs --no-run-if-empty --max-lines=1 passwd -l

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-6(5)
      - NIST-800-53-IA-2
      - NIST-800-53-IA-4(b)
      - PCI-DSS-Req-8.5
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.1
      - accounts_no_uid_except_zero
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy

    - name: Get all /etc/passwd file entries
      ansible.builtin.getent:
        database: passwd
        split: ':'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-6(5)
      - NIST-800-53-IA-2
      - NIST-800-53-IA-4(b)
      - PCI-DSS-Req-8.5
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.1
      - accounts_no_uid_except_zero
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy

    - name: Lock the password of the user accounts other than root with uid 0
      ansible.builtin.command: passwd -l {{ item.key }}
      loop: '{{ getent_passwd | dict2items | rejectattr(''key'', ''search'', ''root'')
        | list }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - item.value.1  == '0'
      tags:
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-6(5)
      - NIST-800-53-IA-2
      - NIST-800-53-IA-4(b)
      - PCI-DSS-Req-8.5
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.1
      - accounts_no_uid_except_zero
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
#### Rule Verify Root Has A Primary GID 0 [ref]
The `root` user should have a primary group of 0.
Rationale: | To help ensure that root-owned files are not inadvertently exposed to other users.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_root_gid_zero
References: |
pcidss | Req-8.1.1
cis | 4.6.4
pcidss4 | 8.2.1, 8.2
#### Rule Ensure the Group Used by pam_wheel.so Module Exists on System and is Empty [ref]
Ensure that the group `sugroup` referenced by `var_pam_wheel_group_for_su` variable and used as value for the `pam_wheel.so` `group` option exists and has no members. This empty group used by `pam_wheel.so` in `/etc/pam.d/su` ensures that no user can run commands with altered privileges through the `su` command. Warning: Note that this rule just ensures the group exists and has no members. This rule does not configure `pam_wheel.so` module. The `pam_wheel.so` module configuration is accomplished by `use_pam_wheel_group_for_su` rule.
Rationale: | The `su` program allows to run commands with a substitute user and group ID. It is commonly used to run commands as the root user. Limiting access to such command is considered a good security practice.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_ensure_pam_wheel_group_empty
References: |
cis | 4.3.6
pcidss4 | 2.2.6, 2.2
#### Rule Ensure Authentication Required for Single User Mode [ref]
Single user mode is used for recovery when the system detects an issue during boot or by manual selection from the bootloader.
Rationale: | Requiring authentication in single user mode prevents an unauthorized user from rebooting the system into single user to gain root privileges without credentials.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_ensure_root_password_configured
References: |
cis | 4.6.6
pcidss4 | 2.2.2, 2.2
#### Rule Ensure that System Accounts Are Locked [ref]
Some accounts are not associated with a human user of the system, and exist to perform some administrative functions. An attacker should not be able to log into these accounts. System accounts are those user accounts with a user ID less than `1000`. If any system account other than `root`, `halt`, `sync`, `shutdown` and `nfsnobody` has an unlocked password, disable it with the command:
    $ sudo usermod -L account
Rationale: | Disabling authentication for default system accounts makes it more difficult for attackers to make use of them to compromise a system.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_no_password_auth_for_systemaccounts
References: |
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | AC-6, CM-6(a)
cis | 4.6.2
pcidss4 | 8.2.2, 8.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    readarray -t systemaccounts < <(awk -F: \
      '($3 < 1000 && $3 != root && $3 != halt && $3 != sync && $3 != shutdown \
      && $3 != nfsnobody) { print $1 }' /etc/passwd)

    for systemaccount in "${systemaccounts[@]}"; do
        usermod -L "$systemaccount"
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.2
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_password_auth_for_systemaccounts
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure that System Accounts Are Locked - Get All Local Users From /etc/passwd
      ansible.builtin.getent:
        database: passwd
        split: ':'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.2
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_password_auth_for_systemaccounts
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure that System Accounts Are Locked - Create local_users Variable From
        getent_passwd Facts
      ansible.builtin.set_fact:
        local_users: '{{ ansible_facts.getent_passwd | dict2items }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.2
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_password_auth_for_systemaccounts
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure that System Accounts Are Locked - Lock System Accounts
      ansible.builtin.user:
        name: '{{ item.key }}'
        password_lock: true
      loop: '{{ local_users }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - item.value[1]|int < 1000
      - item.key not in ['root', 'halt', 'sync', 'shutdown', 'nfsnobody']
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.2
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_password_auth_for_systemaccounts
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure that System Accounts Do Not Run a Shell Upon Login [ref]
Some accounts are not associated with a human user of the system, and exist to perform some administrative functions. Should an attacker be able to log into these accounts, they should not be granted access to a shell. The login shell for each local account is stored in the last field of each line in `/etc/passwd`. System accounts are those user accounts with a user ID less than `1000`. The user ID is stored in the third field. If any system account other than `root` has a login shell, disable it with the command:
    $ sudo usermod -s /sbin/nologin account
Warning: Do not perform the steps in this section on the root account. Doing so might cause the system to become inaccessible.
Rationale: | Ensuring shells are not given to system accounts upon login makes it more difficult for attackers to make use of system accounts.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_no_shelllogin_for_systemaccounts
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8
cobit5 | DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS06.03
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2
iso27001-2013 | A.12.4.1, A.12.4.3, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nist | AC-6, CM-6(a), CM-6(b), CM-6.1(iv)
nist-csf | DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.6.2
ism | 1491
pcidss4 | 8.2.2, 8.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    readarray -t systemaccounts < <(awk -F: '($3 < 1000 && $1 != "root" \
      && $7 != "\/sbin\/shutdown" && $7 != "\/sbin\/halt" && $7 != "\/bin\/sync") \
      { print $1 }' /etc/passwd)

    for systemaccount in "${systemaccounts[@]}"; do
        usermod -s /sbin/nologin "$systemaccount"
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.2
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - no_shelllogin_for_systemaccounts
      - restrict_strategy

    - name: Ensure that System Accounts Do Not Run a Shell Upon Login - Get All Local
        Users From /etc/passwd
      ansible.builtin.getent:
        database: passwd
        split: ':'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.2
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - no_shelllogin_for_systemaccounts
      - restrict_strategy

    - name: Ensure that System Accounts Do Not Run a Shell Upon Login - Create local_users
        Variable From getent_passwd Facts
      ansible.builtin.set_fact:
        local_users: '{{ ansible_facts.getent_passwd | dict2items }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.2
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - no_shelllogin_for_systemaccounts
      - restrict_strategy

    - name: Ensure that System Accounts Do Not Run a Shell Upon Login -  Disable Login
        Shell for System Accounts
      ansible.builtin.user:
        name: '{{ item.key }}'
        shell: /sbin/nologin
      loop: '{{ local_users }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - item.key not in ['root']
      - item.value[1]|int < 1000
      - item.value[5] not in ['/sbin/shutdown', '/sbin/halt', '/bin/sync']
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.2
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - no_shelllogin_for_systemaccounts
      - restrict_strategy
#### Rule Enforce Usage of pam_wheel with Group Parameter for su Authentication [ref]
To ensure that only users who are members of the group set in the `group` option of `pam_wheel.so` module can run commands with altered privileges through the `su` command, make sure that the following line exists in the file `/etc/pam.d/su`:
    auth required pam_wheel.so use_uid group=sugroup
Warning: Note that `ensure_pam_wheel_group_empty` rule complements this requirement by ensuring the referenced group exists and has no members.
Rationale: | The `su` program allows to run commands with a substitute user and group ID. It is commonly used to run commands as the root user. Limiting access to such command is considered a good security practice.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_use_pam_wheel_group_for_su
References: |
cis | 4.3.6
pcidss4 | 2.2.6, 2.2
#### Rule Ensure All Accounts on the System Have Unique User IDs [ref]
Change user IDs (UIDs), or delete accounts, so each has a unique name. Warning: Automatic remediation of this control is not available due to unique requirements of each system.
Rationale: | To assure accountability and prevent unauthenticated access, interactive users must be identified and authenticated to prevent potential misuse and compromise of the system.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_account_unique_id
References: |
pcidss | Req-8.1.1
os-srg | SRG-OS-000104-GPOS-00051, SRG-OS-000121-GPOS-00062
cis | 6.2.4
pcidss4 | 8.2.1, 8.2
#### Rule Ensure All Groups on the System Have Unique Group ID [ref]
Change the group name or delete groups, so each has a unique id. Warning: Automatic remediation of this control is not available due to the unique requirements of each system.
Rationale: | To assure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_group_unique_id
References: |
os-srg | SRG-OS-000104-GPOS-00051
cis | 6.2.5
pcidss4 | 8.2.1, 8.2
#### Rule Ensure All Groups on the System Have Unique Group Names [ref]
Change the group name or delete groups, so each has a unique name. Warning: Automatic remediation of this control is not available due to the unique requirements of each system.
Rationale: | To assure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_group_unique_name
References: |
cis | 6.2.7
pcidss4 | 8.2.1, 8.2
Group Secure Session Configuration Files for Login Accounts Group contains 2 groups and 14 rules
[ref] When a user logs into a Unix account, the system configures the user's session by reading a number of files. Many of these files are located in the user's home directory, and may have weak permissions as a result of user error or misconfiguration. If an attacker can modify or even read certain types of account configuration information, they can often gain full access to the affected user's account. Therefore, it is important to test and correct configuration file permissions for interactive accounts, particularly those of privileged users such as root or system administrators.
Group Ensure that No Dangerous Directories Exist in Root's Path Group contains 2 rules
[ref] The active path of the root account can be obtained by starting a new root shell and running:
    # echo $PATH
This will produce a colon-separated list of directories in the path. Certain path elements could be considered dangerous, as they could lead to root executing unknown or untrusted programs, which could contain malicious code. Since root may sometimes work inside untrusted directories, the `.` character, which represents the current directory, should never be in the root path, nor should any directory which can be written to by an unprivileged or semi-privileged (system) user. It is a good practice for administrators to always execute privileged commands by typing the full path to the command.
#### Rule Ensure that Root's Path Does Not Include World or Group-Writable Directories [ref]
For each element in root's path, run:
    # ls -ld DIR
and ensure that write permissions are disabled for group and other.
Rationale: | Such entries increase the risk that root could execute code provided by unprivileged users, and potentially malicious code.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_root_path_dirs_no_write
References: |
cis-csc | 11, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05
isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4
nist | CM-6(a), CM-6(a)
nist-csf | PR.IP-1
cis | 6.2.8
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | restrict
    - name: Get root paths which are not symbolic links
      ansible.builtin.stat:
        path: '{{ item }}'
      changed_when: false
      failed_when: false
      register: root_paths
      with_items: '{{ ansible_env.PATH.split('':'') }}'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(a)
      - accounts_root_path_dirs_no_write
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable writability to root directories
      ansible.builtin.file:
        path: '{{ item.item }}'
        mode: g-w,o-w
      with_items: '{{ root_paths.results }}'
      when:
      - root_paths.results is defined
      - item.stat.exists
      - not item.stat.islnk
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(a)
      - accounts_root_path_dirs_no_write
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure that Root's Path Does Not Include Relative Paths or Null Directories [ref]
Ensure that none of the directories in root's path is equal to a single `.` character, or that it contains any instances that lead to relative path traversal, such as `..` or beginning a path without the slash (`/`) character. Also ensure that there are no "empty" elements in the path, such as in these examples:
    PATH=:/bin
    PATH=/bin:
    PATH=/bin::/sbin
These empty elements have the same effect as a single `.` character.
Rationale: | Including these entries increases the risk that root could execute code from an untrusted location.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_root_path_no_dot
References: |
cis-csc | 11, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05
isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4
nist | CM-6(a), CM-6(a)
nist-csf | PR.IP-1
cis | 6.2.8
Group Ensure that Users Have Sensible Umask Values Group contains 3 rules
[ref] The umask setting controls the default permissions for the creation of new files. With a default `umask` setting of 077, files and directories created by users will not be readable by any other user on the system. Users who wish to make specific files group- or world-readable can accomplish this by using the chmod command. Additionally, users can make all their files readable to their group by default by setting a `umask` of 027 in their shell configuration files. If default per-user groups exist (that is, if every user has a default group whose name is the same as that user's username and whose only member is the user), then it may even be safe for users to select a `umask` of 007, making it very easy to intentionally share files with groups of which the user is a member.
#### Rule Ensure the Default Bash Umask is Set Correctly [ref]
To ensure the default umask for users of the Bash shell is set properly, add or correct the `umask` setting in `/etc/bashrc` to read as follows:
    umask 027
Rationale: | The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_umask_etc_bashrc
References: |
cis-csc | 18
cobit5 | APO13.01, BAI03.01, BAI03.02, BAI03.03
isa-62443-2009 | 4.3.4.3.3
iso27001-2013 | A.14.1.1, A.14.2.1, A.14.2.5, A.6.1.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | AC-6(1), CM-6(a)
nist-csf | PR.IP-2
os-srg | SRG-OS-000480-GPOS-00228, SRG-OS-000480-GPOS-00227
anssi | R36
cis | 4.6.5
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q bash; }; then

    var_accounts_user_umask='027'

    grep -q "^[^#]*\bumask" /etc/bashrc && \
      sed -i -E -e "s/^([^#]*\bumask)[[:space:]]+[[:digit:]]+/\1 $var_accounts_user_umask/g" /etc/bashrc
    if ! [ $? -eq 0 ]; then
        echo "umask $var_accounts_user_umask" >> /etc/bashrc
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_bashrc
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_user_umask # promote to variable
      set_fact:
        var_accounts_user_umask: !!str 027
      tags:
        - always

    - name: Check if umask in /etc/bashrc is already set
      ansible.builtin.lineinfile:
        path: /etc/bashrc
        regexp: ^[^#]*\bumask\s+\d+$
        state: absent
      check_mode: true
      changed_when: false
      register: umask_replace
      when:
      - '"kernel" in ansible_facts.packages'
      - '"bash" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_bashrc
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Replace user umask in /etc/bashrc
      ansible.builtin.replace:
        path: /etc/bashrc
        regexp: ^([^#]*\b)umask\s+\d+$
        replace: \g<1>umask {{ var_accounts_user_umask }}
      when:
      - '"kernel" in ansible_facts.packages'
      - '"bash" in ansible_facts.packages'
      - umask_replace.found > 0
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_bashrc
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure the Default umask is Appended Correctly
      ansible.builtin.lineinfile:
        create: true
        path: /etc/bashrc
        line: umask {{ var_accounts_user_umask }}
      when:
      - '"kernel" in ansible_facts.packages'
      - '"bash" in ansible_facts.packages'
      - umask_replace.found == 0
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_bashrc
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure the Default Umask is Set Correctly in login.defs [ref]
To ensure the default umask controlled by `/etc/login.defs` is set properly, add or correct the `UMASK` setting in `/etc/login.defs` to read as follows:
    UMASK 027
Rationale: | The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read and written to by unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_umask_etc_login_defs
References: |
cis-csc | 11, 18, 3, 9
cobit5 | APO13.01, BAI03.01, BAI03.02, BAI03.03, BAI10.01, BAI10.02, BAI10.03, BAI10.05
isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.1.1, A.14.2.1, A.14.2.2, A.14.2.3, A.14.2.4, A.14.2.5, A.6.1.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | AC-6(1), CM-6(a)
nist-csf | PR.IP-1, PR.IP-2
os-srg | SRG-OS-000480-GPOS-00228
anssi | R36
cis | 4.6.5
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q shadow-utils; }; then

    var_accounts_user_umask='027'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^UMASK")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s %s" "$stripped_key" "$var_accounts_user_umask"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^UMASK\\>" "/etc/login.defs"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^UMASK\\>.*/$escaped_formatted_output/gi" "/etc/login.defs"
    else
        if [[ -s "/etc/login.defs" ]] && [[ -n "$(tail -c 1 -- "/etc/login.defs" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/login.defs"
        fi
        printf '%s\n' "$formatted_output" >> "/etc/login.defs"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_user_umask # promote to variable
      set_fact:
        var_accounts_user_umask: !!str 027
      tags:
        - always

    - name: Check if UMASK is already set
      ansible.builtin.lineinfile:
        path: /etc/login.defs
        regexp: ^(\s*)UMASK\s+.*
        state: absent
      check_mode: true
      changed_when: false
      register: result_umask_is_set
      when:
      - '"kernel" in ansible_facts.packages'
      - '"shadow-utils" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Replace user UMASK in /etc/login.defs
      ansible.builtin.replace:
        path: /etc/login.defs
        regexp: ^(\s*)UMASK(\s+).*
        replace: \g<1>UMASK\g<2>{{ var_accounts_user_umask }}
      when:
      - '"kernel" in ansible_facts.packages'
      - '"shadow-utils" in ansible_facts.packages'
      - result_umask_is_set.found > 0
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure the Default UMASK is Appended Correctly
      ansible.builtin.lineinfile:
        create: true
        path: /etc/login.defs
        line: UMASK {{ var_accounts_user_umask }}
      when:
      - '"kernel" in ansible_facts.packages'
      - '"shadow-utils" in ansible_facts.packages'
      - result_umask_is_set.found == 0
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_login_defs
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure the Default Umask is Set Correctly in /etc/profile [ref]
To ensure the default umask controlled by `/etc/profile` is set properly, add or correct the `umask` setting in `/etc/profile` to read as follows:
    umask 027
Note that `/etc/profile` also reads scripts within `/etc/profile.d` directory. These scripts are also valid files to set umask value. Therefore, they should also be considered during the check and properly remediated, if necessary.
Rationale: | The umask value influences the permissions assigned to files when they are created. A misconfigured umask value could result in files with excessive permissions that can be read or written to by unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_umask_etc_profile
References: |
cis-csc | 18
cobit5 | APO13.01, BAI03.01, BAI03.02, BAI03.03
isa-62443-2009 | 4.3.4.3.3
iso27001-2013 | A.14.1.1, A.14.2.1, A.14.2.5, A.6.1.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | AC-6(1), CM-6(a)
nist-csf | PR.IP-2
os-srg | SRG-OS-000480-GPOS-00228, SRG-OS-000480-GPOS-00227
anssi | R36
cis | 4.6.5
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    var_accounts_user_umask='027'

    readarray -t profile_files < <(find /etc/profile.d/ -type f -name '*.sh' -or -name 'sh.local')

    for file in "${profile_files[@]}" /etc/profile; do
      grep -qE '^[^#]*umask' "$file" && sed -i -E "s/^(\s*umask\s*)[0-7]+/\1$var_accounts_user_umask/g" "$file"
    done

    if ! grep -qrE '^[^#]*umask' /etc/profile*; then
      echo "umask $var_accounts_user_umask" >> /etc/profile
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_profile
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_user_umask # promote to variable
      set_fact:
        var_accounts_user_umask: !!str 027
      tags:
        - always

    - name: Ensure the Default Umask is Set Correctly in /etc/profile - Locate Profile
        Configuration Files Where umask Is Defined
      ansible.builtin.find:
        paths:
        - /etc/profile.d
        patterns:
        - sh.local
        - '*.sh'
        contains: ^[\s]*umask\s+\d+
      register: result_profile_d_files
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_profile
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure the Default Umask is Set Correctly in /etc/profile - Replace Existing
        umask Value in Files From /etc/profile.d
      ansible.builtin.replace:
        path: '{{ item.path }}'
        regexp: ^(\s*)umask\s+\d+
        replace: \1umask {{ var_accounts_user_umask }}
      loop: '{{ result_profile_d_files.files }}'
      register: result_umask_replaced_profile_d
      when:
      - '"kernel" in ansible_facts.packages'
      - result_profile_d_files.matched
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_profile
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure the Default Umask is Set Correctly in /etc/profile - Ensure umask Is
        Set in /etc/profile if Not Already Set Elsewhere
      ansible.builtin.lineinfile:
        create: true
        mode: 420
        path: /etc/profile
        line: umask {{ var_accounts_user_umask }}
      when:
      - '"kernel" in ansible_facts.packages'
      - not result_profile_d_files.matched
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_profile
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure the Default Umask is Set Correctly in /etc/profile - Ensure umask Value
        For All Existing umask Definition in /etc/profile
      ansible.builtin.replace:
        path: /etc/profile
        regexp: ^(\s*)umask\s+\d+
        replace: \1umask {{ var_accounts_user_umask }}
      register: result_umask_replaced_profile
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - accounts_umask_etc_profile
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Set Interactive Session Timeout [ref]
Setting the `TMOUT` option in `/etc/profile` ensures that all user sessions will terminate based on inactivity. A value of `0` (zero) disables the automatic logout feature and is therefore not a compliant setting. The value of TMOUT should be a positive integer, exported, and read only. The `TMOUT` setting in a file loaded by `/etc/profile`, e.g. `/etc/profile.d/tmout.sh` should read as follows:
    typeset -xr TMOUT=900
or
    declare -xr TMOUT=900
Using the `typeset` keyword is preferred for wider compatibility with ksh and other shells.
Rationale: | Terminating an idle session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been left unattended.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_tmout
References: |
cis-csc | 1, 12, 15, 16
cobit5 | DSS05.04, DSS05.10, DSS06.10
cui | 3.1.11
isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9
iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3
nerc-cip | CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nist | AC-12, SC-10, AC-2(5), CM-6(a)
nist-csf | PR.AC-7
os-srg | SRG-OS-000163-GPOS-00072, SRG-OS-000029-GPOS-00010
anssi | R32
cis | 4.6.3
pcidss4 | 8.6.1, 8.6
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    var_accounts_tmout='900'

    # if 0, no occurrence of tmout found, if 1, occurrence found
    tmout_found=0

    for f in /etc/profile /etc/profile.d/*.sh; do

        if grep --silent '^[^#].*TMOUT' $f; then
            sed -i -E "s/^(.*)TMOUT\s*=\s*(\w|\$)*(.*)$/typeset -xr TMOUT=$var_accounts_tmout\3/g" $f
            tmout_found=1
        fi
    done

    if [ $tmout_found -eq 0 ]; then
            echo -e "\n# Set TMOUT to $var_accounts_tmout per security requirements" >> /etc/profile.d/tmout.sh
            echo "typeset -xr TMOUT=$var_accounts_tmout" >> /etc/profile.d/tmout.sh
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSSv4-8.6
      - PCI-DSSv4-8.6.1
      - accounts_tmout
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_tmout # promote to variable
      set_fact:
        var_accounts_tmout: !!str 900
      tags:
        - always

    - name: Correct any occurrence of TMOUT in /etc/profile
      ansible.builtin.replace:
        path: /etc/profile
        regexp: ^[^#].*TMOUT=.*
        replace: typeset -xr TMOUT={{ var_accounts_tmout }}
      register: profile_replaced
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSSv4-8.6
      - PCI-DSSv4-8.6.1
      - accounts_tmout
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set Interactive Session Timeout
      ansible.builtin.lineinfile:
        path: /etc/profile.d/tmout.sh
        create: true
        regexp: TMOUT=
        line: typeset -xr TMOUT={{ var_accounts_tmout }}
        state: present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSSv4-8.6
      - PCI-DSSv4-8.6.1
      - accounts_tmout
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule User Initialization Files Must Be Group-Owned By The Primary Group [ref]
Change the group owner of interactive users files to the group found in
    /etc/passwd
for the user. To change the group owner of a local interactive user home directory, use the following command:
    $ sudo chgrp USER_GROUP /home/USER/.INIT_FILE
This rule ensures every initialization file related to an interactive user is group-owned by an interactive user. Warning: Due to OVAL limitation, this rule can report a false negative in a specific situation where two interactive users swap the group-ownership of their respective initialization files.
Rationale: | Local initialization files for interactive users are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_user_dot_group_ownership
References: |
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.2.11
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    awk -F: '{if ($4 >= 1000 && $4 != 65534) print $4":"$6}' /etc/passwd | while IFS=: read -r gid home; do find -P "$home" -maxdepth 1 -type f -name "\.[^.]*" -exec chgrp -f --no-dereference -- $gid "{}" \;; done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - accounts_user_dot_group_ownership
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: User Initialization Files Must Be Group-Owned By The Primary Group - Get interactive
        users from passwd file
      ansible.builtin.getent:
        database: passwd
      register: passwd_entries
      when: '"kernel" in ansible_facts.packages'
      tags:
      - accounts_user_dot_group_ownership
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: User Initialization Files Must Be Group-Owned By The Primary Group - Create
        list of interactive users with GID and home directory
      ansible.builtin.set_fact:
        interactive_users: '{{ interactive_users | default([]) + [{''home'': item.value[4],
          ''gid'': item.value[2]}] }}'
      loop: '{{ passwd_entries.ansible_facts.getent_passwd | dict2items }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - item.value[2] | int >= 1000 | int
      - item.value[2] | int != 65534 | int
      - item.value[4] != ""
      tags:
      - accounts_user_dot_group_ownership
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: User Initialization Files Must Be Group-Owned By The Primary Group - Find
        dot files in interactive user home directories
      ansible.builtin.find:
        paths: '{{ item.home }}'
        patterns: .*
        file_type: file
        hidden: true
        depth: 1
        follow: false
      register: user_dotfiles
      loop: '{{ interactive_users | default([]) }}'
      failed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - item.home != ""
      tags:
      - accounts_user_dot_group_ownership
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: User Initialization Files Must Be Group-Owned By The Primary Group - Set correct
        group ownership for user initialization files
      ansible.builtin.file:
        path: '{{ item.1.path }}'
        group: '{{ item.0.item.gid }}'
        follow: false
      loop: '{{ user_dotfiles.results | subelements(''files'', skip_missing=True) }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - item.0 is not skipped
      - item.1.path is defined
      tags:
      - accounts_user_dot_group_ownership
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule User Initialization Files Must Be Owned By the Primary User [ref]
Set the owner of the user initialization files for interactive users to the primary owner with the following command:
    $ sudo chown USER /home/USER/.*
This rule ensures every initialization file related to an interactive user is owned by an interactive user. Warning: Due to OVAL limitation, this rule can report a false negative in a specific situation where two interactive users swap the ownership of their respective initialization files.
Rationale: | Local initialization files are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_user_dot_user_ownership
References: |
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.2.11
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    awk -F: '{if ($3 >= 1000 && $3 != 65534) print $3":"$6}' /etc/passwd | while IFS=: read -r uid home; do find -P "$home" -maxdepth 1 -type f -name "\.[^.]*" -exec chown -f --no-dereference -- $uid "{}" \;; done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - accounts_user_dot_user_ownership
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: User Initialization Files Must Be Owned By the Primary User - Get interactive
        users from passwd file
      ansible.builtin.getent:
        database: passwd
      register: passwd_entries
      when: '"kernel" in ansible_facts.packages'
      tags:
      - accounts_user_dot_user_ownership
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: User Initialization Files Must Be Owned By the Primary User - Create list
        of interactive users with UID and home directory
      ansible.builtin.set_fact:
        interactive_users: '{{ interactive_users | default([]) + [{''uid'': item.value[1],
          ''home'': item.value[4], ''username'': item.key}] }}'
      loop: '{{ passwd_entries.ansible_facts.getent_passwd | dict2items }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - item.value[1] | int >= 1000 | int
      - item.value[1] | int != 65534 | int
      - item.value[4] != ""
      tags:
      - accounts_user_dot_user_ownership
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: User Initialization Files Must Be Owned By the Primary User - Find dot files
        in interactive user home directories
      ansible.builtin.find:
        paths: '{{ item.home }}'
        patterns: .*
        file_type: file
        hidden: true
        depth: 1
        follow: false
      register: user_dotfiles
      loop: '{{ interactive_users | default([]) }}'
      failed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - item.home != ""
      tags:
      - accounts_user_dot_user_ownership
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: User Initialization Files Must Be Owned By the Primary User - Set correct
        ownership for user initialization files
      ansible.builtin.file:
        path: '{{ item.1.path }}'
        owner: '{{ item.0.item.username }}'
        follow: false
      loop: '{{ user_dotfiles.results | subelements(''files'', skip_missing=True) }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - item.0 is not skipped
      - item.0 is not failed
      - item.0.item is defined
      - item.0.item.username is defined
      - item.1.path is defined
      tags:
      - accounts_user_dot_user_ownership
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule All Interactive Users Home Directories Must Exist [ref]
Create home directories to all local interactive users that currently do not have a home directory assigned. Use the following commands to create the user home directory assigned in `/etc/passwd`:
    $ sudo mkdir /home/USER
Rationale: | If a local interactive user has a home directory defined that does not exist, the user may be given access to the / directory as the current working directory upon logon. This could create a Denial of Service because the user would not be able to access their logon configuration files, and it may give them visibility to system files they normally would not be able to access.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_user_interactive_home_directory_exists
References: |
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.2.10
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    for user in $(awk -F':' '{ if ($3 >= 1000 && $3 != 65534) print $1}' /etc/passwd); do
        mkhomedir_helper $user 0077;
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - accounts_user_interactive_home_directory_exists
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Get all local users from /etc/passwd
      ansible.builtin.getent:
        database: passwd
        split: ':'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - accounts_user_interactive_home_directory_exists
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Create local_users variable from the getent output
      ansible.builtin.set_fact:
        local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - accounts_user_interactive_home_directory_exists
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure interactive users have a home directory exists
      ansible.builtin.user:
        name: '{{ item.key }}'
        create_home: true
      loop: '{{ local_users }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - item.value[1]|int >= 1000
      - item.value[1]|int != 65534
      tags:
      - accounts_user_interactive_home_directory_exists
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure users' .netrc Files are not group or world accessible [ref]
While the system administrator can establish secure permissions for users' .netrc files, the users can easily override these. This rule ensures every .netrc file or directory under the home directory related to an interactive user is not group or world accessible
Rationale: | .netrc files may contain unencrypted passwords that may be used to attack other systems. Note: While the complete removal of .netrc files is recommended, if any are required on the system, secure permissions must be applied.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_accounts_users_netrc_file_permissions
References: |
cis | 6.2.11
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    for user in $(awk -F':' '{ if ($3 >= 1000 && $3 != 65534) print $1 }' /etc/passwd); do
        home_dir=$(getent passwd "$user" | cut -d: -f6)
        find "${home_dir}/.netrc" -exec chmod 0600 {} \;
    done
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Get all local users from /etc/passwd
      ansible.builtin.getent:
        database: passwd
        split: ':'
      tags:
      - accounts_users_netrc_file_permissions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Create local_users variable from the getent output
      ansible.builtin.set_fact:
        local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
      tags:
      - accounts_users_netrc_file_permissions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Test for existence of .netrc file in home directories to avoid creating them,
        but only fixing permissions
      ansible.builtin.stat:
        path: '{{ item.value[4] }}/.netrc'
      register: path_exists
      loop: '{{ local_users }}'
      when:
      - item.value[1]|int >= 1000
      - item.value[1]|int != 65534
      tags:
      - accounts_users_netrc_file_permissions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure group and world cannot access respective .netrc files
      ansible.builtin.file:
        path: '{{ item.item.value[4] }}/.netrc'
        mode: '0600'
        state: file
      loop: '{{ path_exists.results }}'
      when: item.stat is defined and item.stat.exists
      tags:
      - accounts_users_netrc_file_permissions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule All Interactive User Home Directories Must Be Group-Owned By The Primary Group [ref]
Change the group owner of interactive users home directory to the group found in `/etc/passwd`. To change the group owner of interactive users home directory, use the following command:
    $ sudo chgrp USER_GROUP /home/USER
This rule ensures every home directory related to an interactive user is group-owned by an interactive user. It also ensures that interactive users are group-owners of one and only one home directory. Warning: Due to OVAL limitation, this rule can report a false negative in a specific situation where two interactive users swap the group-ownership of their respective home directories.
Rationale: | If the Group Identifier (GID) of a local interactive users home directory is not the same as the primary GID of the user, this would allow unauthorized access to the users files, and users that share the same group may not be able to access files that they legitimately should.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupownership_home_directories
References: |
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.2.10
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    awk -F':' '{ if ($3 >= 1000 && $3 != 65534) system("chgrp -f " $4" "$6) }' /etc/passwd
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Get all local users from /etc/passwd
      ansible.builtin.getent:
        database: passwd
        split: ':'
      tags:
      - file_groupownership_home_directories
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Create local_users variable from the getent output
      ansible.builtin.set_fact:
        local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
      tags:
      - file_groupownership_home_directories
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Test for existence of home directories to avoid creating them, but only fixing
        group ownership
      ansible.builtin.stat:
        path: '{{ item.value[4] }}'
      register: path_exists
      loop: '{{ local_users }}'
      when:
      - item.value[1]|int >= 1000
      - item.value[1]|int != 65534
      tags:
      - file_groupownership_home_directories
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure interactive local users are the group-owners of their respective home
        directories
      ansible.builtin.file:
        path: '{{ item.0.value[4] }}'
        group: '{{ item.0.value[2] }}'
      loop: '{{ local_users|zip(path_exists.results)|list }}'
      when: item.1.stat is defined and item.1.stat.exists
      tags:
      - file_groupownership_home_directories
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule All Interactive User Home Directories Must Be Owned By The Primary User [ref]
Change the owner of interactive users home directories to that correct owner. To change the owner of a interactive users home directory, use the following command:
    $ sudo chown USER /home/USER
This rule ensures every home directory related to an interactive user is owned by an interactive user. It also ensures that interactive users are owners of one and only one home directory. Warning: Due to OVAL limitation, this rule can report a false negative in a specific situation where two interactive users swap the ownership of their respective home directories.
Rationale: | If a local interactive user does not own their home directory, unauthorized users could access or modify the user's files, and the users may not be able to access their own files.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_ownership_home_directories
References: |
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.2.10
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    awk -F':' '{ if ($3 >= 1000 && $3 != 65534) system("chown -f " $3" "$6) }' /etc/passwd
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Get all local users from /etc/passwd
      ansible.builtin.getent:
        database: passwd
        split: ':'
      tags:
      - file_ownership_home_directories
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Create local_users variable from the getent output
      ansible.builtin.set_fact:
        local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
      tags:
      - file_ownership_home_directories
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Test for existence of home directories to avoid creating them, but only fixing
        ownership
      ansible.builtin.stat:
        path: '{{ item.value[4] }}'
      register: path_exists
      loop: '{{ local_users }}'
      when:
      - item.value[1]|int >= 1000
      - item.value[1]|int != 65534
      tags:
      - file_ownership_home_directories
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure interactive local users are the owners of their respective home directories
      ansible.builtin.file:
        path: '{{ item.0.value[4] }}'
        owner: '{{ item.0.value[1] }}'
      loop: '{{ local_users|zip(path_exists.results)|list }}'
      when: item.1.stat is defined and item.1.stat.exists
      tags:
      - file_ownership_home_directories
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure All User Initialization Files Have Mode 0740 Or Less Permissive [ref]
Set the mode of the user initialization files to `0740` with the following command:
    $ sudo chmod 0740 /home/USER/.INIT_FILE
Rationale: | Local initialization files are used to configure the user's shell environment upon logon. Malicious modification of these files could compromise accounts upon logon.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permission_user_init_files
References: |
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.2.11
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    var_user_initialization_files_regex='^\.[\w\- ]+$'

    readarray -t interactive_users < <(awk -F: '$3>=1000   {print $1}' /etc/passwd)
    readarray -t interactive_users_home < <(awk -F: '$3>=1000   {print $6}' /etc/passwd)
    readarray -t interactive_users_shell < <(awk -F: '$3>=1000   {print $7}' /etc/passwd)

    USERS_IGNORED_REGEX='nobody|nfsnobody'

    for (( i=0; i<"${#interactive_users[@]}"; i++ )); do
        if ! grep -qP "$USERS_IGNORED_REGEX" <<< "${interactive_users[$i]}" && \
            [ "${interactive_users_shell[$i]}" != "/sbin/nologin" ]; then

            readarray -t init_files < <(find "${interactive_users_home[$i]}" -maxdepth 1 \
                -exec basename {} \; | grep -P "$var_user_initialization_files_regex")
            for file in "${init_files[@]}"; do
                chmod u-s,g-wxs,o= "${interactive_users_home[$i]}/$file"
            done
        fi
    done
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: XCCDF Value var_user_initialization_files_regex # promote to variable
      set_fact:
        var_user_initialization_files_regex: !!str ^\.[\w\- ]+$
      tags:
        - always

    - name: Ensure All User Initialization Files Have Mode 0740 Or Less Permissive - Gather
        User Info
      ansible.builtin.getent:
        database: passwd
      tags:
      - file_permission_user_init_files
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure All User Initialization Files Have Mode 0740 Or Less Permissive - Find
        Init Files
      ansible.builtin.find:
        paths: '{{ item.value[4] }}'
        pattern: '{{ var_user_initialization_files_regex }}'
        hidden: true
        use_regex: true
      with_dict: '{{ ansible_facts.getent_passwd }}'
      when:
      - item.value[4] != "/sbin/nologin"
      - item.key not in ["nobody", "nfsnobody"]
      - item.value[1] | int >= 1000
      register: found_init_files
      tags:
      - file_permission_user_init_files
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure All User Initialization Files Have Mode 0740 Or Less Permissive - Fix
        Init Files Permissions
      ansible.builtin.file:
        path: '{{ item.1.path }}'
        mode: u-s,g-wxs,o=
      loop: '{{ q(''ansible.builtin.subelements'', found_init_files.results, ''files'',
        {''skip_missing'': True}) }}'
      tags:
      - file_permission_user_init_files
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule All Interactive User Home Directories Must Have mode 0750 Or Less Permissive [ref]
Change the mode of interactive users home directories to `0750`. To change the mode of interactive users home directory, use the following command:
    $ sudo chmod 0750 /home/USER
Rationale: | Excessive permissions on local interactive user home directories may allow unauthorized access to user files by other users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_home_directories
References: |
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.2.10
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    for home_dir in $(awk -F':' '{ if ($3 >= 1000 && $3 != 65534 && $6 != "/") print $6 }' /etc/passwd); do
        # Only update the permissions when necessary. This will avoid changing the inode timestamp when
        # the permission is already defined as expected, therefore not impacting in possible integrity
        # check systems that also check inodes timestamps.
        find "$home_dir" -maxdepth 0 -perm /7027 \! -type l -exec chmod u-s,g-w-s,o=- {} \;
    done
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Get all local users from /etc/passwd
      ansible.builtin.getent:
        database: passwd
        split: ':'
      tags:
      - file_permissions_home_directories
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Create local_users variable from the getent output
      ansible.builtin.set_fact:
        local_users: '{{ ansible_facts.getent_passwd|dict2items }}'
      tags:
      - file_permissions_home_directories
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Test for existence home directories to avoid creating them.
      ansible.builtin.stat:
        path: '{{ item.value[4] }}'
      register: path_exists
      loop: '{{ local_users }}'
      when:
      - item.value[1]|int >= 1000
      - item.value[1]|int != 65534
      - item.value[4] != "/"
      tags:
      - file_permissions_home_directories
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure interactive local users have proper permissions on their respective
        home directories
      ansible.builtin.file:
        path: '{{ item.0.value[4] }}'
        mode: u-s,g-w-s,o=-
        follow: false
        recurse: false
      loop: '{{ local_users|zip(path_exists.results)|list }}'
      when: item.1.stat is defined and item.1.stat.exists
      tags:
      - file_permissions_home_directories
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
Group GRUB2 bootloader configuration Group contains 1 group and 6 rules
[ref] During the boot process, the boot loader is responsible for starting the execution of the kernel and passing options to it. The boot loader allows for the selection of different kernels - possibly on different partitions or media. The default Amazon Linux 2023 boot loader for x86 systems is called GRUB2. Options it can pass to the kernel include single-user mode, which provides root access without any authentication, and the ability to disable SELinux. To prevent local users from modifying the boot parameters and endangering security, protect the boot loader configuration with a password and ensure its configuration file's permissions are set properly.
Group Non-UEFI GRUB2 bootloader configuration Group contains 6 rules
[ref] Non-UEFI GRUB2 bootloader configuration
#### Rule Verify /boot/grub2/grub.cfg Group Ownership [ref]
The file `/boot/grub2/grub.cfg` should be group-owned by the `root` group to prevent destruction or modification of the file. To properly set the group owner of `/boot/grub2/grub.cfg`, run the command:
    $ sudo chgrp root /boot/grub2/grub.cfg
Rationale: | The `root` group is a highly-privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_grub2_cfg
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
cui | 3.4.5
hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii)
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-7.1
os-srg | SRG-OS-000480-GPOS-00227
anssi | R29
cis | 1.4.1
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if ( rpm --quiet -q grub2-common && rpm --quiet -q kernel ) && { ( ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); }; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/boot/grub2/grub.cfg" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /boot/grub2/grub.cfg
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupowner_grub2_cfg_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_grub2_cfg_newgroup: '0'
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /boot/grub2/grub.cfg
      ansible.builtin.stat:
        path: /boot/grub2/grub.cfg
      register: file_exists
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /boot/grub2/grub.cfg
      ansible.builtin.file:
        path: /boot/grub2/grub.cfg
        follow: false
        group: '{{ file_groupowner_grub2_cfg_newgroup }}'
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify /boot/grub2/user.cfg Group Ownership [ref]
The file `/boot/grub2/user.cfg` should be group-owned by the `root` group to prevent reading or modification of the file. To properly set the group owner of `/boot/grub2/user.cfg`, run the command:
    $ sudo chgrp root /boot/grub2/user.cfg
Rationale: | The `root` group is a highly-privileged group. Furthermore, the group-owner of this file should not have any access privileges anyway. Non-root users who read the boot parameters may be able to identify weaknesses in security upon boot and be able to exploit them.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_user_cfg
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
cui | 3.4.5
hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii)
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-7.1
os-srg | SRG-OS-000480-GPOS-00227
anssi | R29
cis | 1.4.1
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if ( rpm --quiet -q grub2-common && rpm --quiet -q kernel ) && { ( ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); }; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/boot/grub2/user.cfg" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /boot/grub2/user.cfg
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_user_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupowner_user_cfg_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_user_cfg_newgroup: '0'
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_user_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /boot/grub2/user.cfg
      ansible.builtin.stat:
        path: /boot/grub2/user.cfg
      register: file_exists
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_user_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /boot/grub2/user.cfg
      ansible.builtin.file:
        path: /boot/grub2/user.cfg
        follow: false
        group: '{{ file_groupowner_user_cfg_newgroup }}'
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_user_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify /boot/grub2/grub.cfg User Ownership [ref]
The file `/boot/grub2/grub.cfg` should be owned by the `root` user to prevent destruction or modification of the file. To properly set the owner of `/boot/grub2/grub.cfg`, run the command:
    $ sudo chown root /boot/grub2/grub.cfg
Rationale: | Only root should be able to modify important boot parameters.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_grub2_cfg
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
cui | 3.4.5
hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii)
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-7.1
os-srg | SRG-OS-000480-GPOS-00227
anssi | R29
cis | 1.4.1
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if ( rpm --quiet -q grub2-common && rpm --quiet -q kernel ) && { ( ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); }; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/boot/grub2/grub.cfg" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /boot/grub2/grub.cfg
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_owner_grub2_cfg_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_grub2_cfg_newown: '0'
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /boot/grub2/grub.cfg
      ansible.builtin.stat:
        path: /boot/grub2/grub.cfg
      register: file_exists
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /boot/grub2/grub.cfg
      ansible.builtin.file:
        path: /boot/grub2/grub.cfg
        follow: false
        owner: '{{ file_owner_grub2_cfg_newown }}'
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify /boot/grub2/user.cfg User Ownership [ref]
The file `/boot/grub2/user.cfg` should be owned by the `root` user to prevent reading or modification of the file. To properly set the owner of `/boot/grub2/user.cfg`, run the command:
    $ sudo chown root /boot/grub2/user.cfg
Rationale: | Only root should be able to modify important boot parameters. Also, non-root users who read the boot parameters may be able to identify weaknesses in security upon boot and be able to exploit them.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_user_cfg
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
cui | 3.4.5
hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii)
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-7.1
anssi | R29
cis | 1.4.1
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if ( rpm --quiet -q grub2-common && rpm --quiet -q kernel ) && { ( ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); }; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/boot/grub2/user.cfg" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /boot/grub2/user.cfg
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_user_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_owner_user_cfg_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_user_cfg_newown: '0'
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_user_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /boot/grub2/user.cfg
      ansible.builtin.stat:
        path: /boot/grub2/user.cfg
      register: file_exists
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_user_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /boot/grub2/user.cfg
      ansible.builtin.file:
        path: /boot/grub2/user.cfg
        follow: false
        owner: '{{ file_owner_user_cfg_newown }}'
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-7.1
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_user_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify /boot/grub2/grub.cfg Permissions [ref]
File permissions for `/boot/grub2/grub.cfg` should be set to 600. To properly set the permissions of `/boot/grub2/grub.cfg`, run the command:
    $ sudo chmod 600 /boot/grub2/grub.cfg
Rationale: | Proper permissions ensure that only the root user can modify important boot parameters.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_grub2_cfg
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
cui | 3.4.5
hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii)
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
anssi | R29
cis | 1.4.1
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if ( rpm --quiet -q grub2-common && rpm --quiet -q kernel ) && { ( ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); }; then

    chmod u-xs,g-xwrs,o-xwrt /boot/grub2/grub.cfg

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /boot/grub2/grub.cfg
      ansible.builtin.stat:
        path: /boot/grub2/grub.cfg
      register: file_exists
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      tags:
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xwrs,o-xwrt on /boot/grub2/grub.cfg
      ansible.builtin.file:
        path: /boot/grub2/grub.cfg
        mode: u-xs,g-xwrs,o-xwrt
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_grub2_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify /boot/grub2/user.cfg Permissions [ref]
File permissions for `/boot/grub2/user.cfg` should be set to 600. To properly set the permissions of `/boot/grub2/user.cfg`, run the command:
    $ sudo chmod 600 /boot/grub2/user.cfg
Rationale: | Proper permissions ensure that only the root user can read or modify important boot parameters.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_user_cfg
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
cui | 3.4.5
hipaa | 164.308(a)(1)(ii)(B), 164.308(a)(7)(i), 164.308(a)(7)(ii)(A), 164.310(a)(1), 164.310(a)(2)(i), 164.310(a)(2)(ii), 164.310(a)(2)(iii), 164.310(b), 164.310(c), 164.310(d)(1), 164.310(d)(2)(iii)
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
anssi | R29
cis | 1.4.1
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if ( rpm --quiet -q grub2-common && rpm --quiet -q kernel ) && { ( ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); }; then

    chmod u-xs,g-xwrs,o-xwrt /boot/grub2/user.cfg

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_user_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /boot/grub2/user.cfg
      ansible.builtin.stat:
        path: /boot/grub2/user.cfg
      register: file_exists
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      tags:
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_user_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xwrs,o-xwrt on /boot/grub2/user.cfg
      ansible.builtin.file:
        path: /boot/grub2/user.cfg
        mode: u-xs,g-xwrs,o-xwrt
      when:
      - ( "grub2-common" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
      - not ( ansible_virtualization_type in ["docker", "lxc", "openvz", "podman", "container"]
        )
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-171-3.4.5
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_user_cfg
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
Group Configure Syslog Group contains 4 groups and 12 rules
[ref] The syslog service has been the default Unix logging mechanism for many years. It has a number of downsides, including inconsistent log format, lack of authentication for received messages, and lack of authentication, encryption, or reliable transport for messages sent over a network. However, due to its long history, syslog is a de facto standard which is supported by almost all Unix applications. In Amazon Linux 2023, rsyslog has replaced ksyslogd as the syslog daemon of choice, and it includes some additional security features such as reliable, connection-oriented (i.e. TCP) transmission of logs, the option to log to database formats, and the encryption of log data en route to a central logging server. This section discusses how to configure rsyslog for best effect, and how to use tools provided with the system to maintain and monitor logs.
Group Ensure Proper Configuration of Log Files Group contains 3 rules
[ref] The file `/etc/rsyslog.conf` controls where log message are written. These are controlled by lines called rules, which consist of a selector and an action. These rules are often customized depending on the role of the system, the requirements of the environment, and whatever may enable the administrator to most effectively make use of log data. The default rules in Amazon Linux 2023 are:
    *.info;mail.none;authpriv.none;cron.none                /var/log/messages
    authpriv.*                                              /var/log/secure
    mail.*                                                  -/var/log/maillog
    cron.*                                                  /var/log/cron
    *.emerg                                                 *
    uucp,news.crit                                          /var/log/spooler
    local7.*                                                /var/log/boot.log
See the man page `rsyslog.conf(5)` for more information. Note that the `rsyslog` daemon can be configured to use a timestamp format that some log processing programs may not understand. If this occurs, edit the file `/etc/rsyslog.conf` and add or edit the following line:
    $ ActionFileDefaultTemplate RSYSLOG_TraditionalFileFormat
#### Rule Ensure Log Files Are Owned By Appropriate Group [ref]
The group-owner of all log files written by `rsyslog` should be `root`. These log files are determined by the second part of each Rule line in `/etc/rsyslog.conf` and typically all appear in `/var/log`. For each log file LOGFILE referenced in `/etc/rsyslog.conf`, run the following command to inspect the file's group owner:
    $ ls -l LOGFILE
If the owner is not `root`, run the following command to correct this:
    $ sudo chgrp root LOGFILE
Rationale: | The log files generated by rsyslog contain valuable information regarding system configuration, user authentication, and other such information. Log files should be protected from unauthorized access.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_rsyslog_files_groupownership
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-10.5.1, Req-10.5.2
anssi | R71
cis | 5.1.3
ism | 0988, 1405
pcidss4 | 10.3.2, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && rpm --quiet -q rsyslog; then

    # List of log file paths to be inspected for correct permissions
    # * Primarily inspect log file paths listed in /etc/rsyslog.conf
    RSYSLOG_ETC_CONFIG="/etc/rsyslog.conf"
    # * And also the log file paths listed after rsyslog's $IncludeConfig directive
    #   (store the result into array for the case there's shell glob used as value of IncludeConfig)
    readarray -t OLD_INC < <(grep -e "\$IncludeConfig[[:space:]]\+[^[:space:];]\+" /etc/rsyslog.conf | cut -d ' ' -f 2)
    readarray -t RSYSLOG_INCLUDE_CONFIG < <(for INCPATH in "${OLD_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
    readarray -t NEW_INC < <(sed -n '/^\s*include(/,/)/Ip' /etc/rsyslog.conf | sed -n 's@.*file\s*=\s*"\([/[:alnum:][:punct:]]*\)".*@\1@Ip')
    readarray -t RSYSLOG_INCLUDE < <(for INCPATH in "${NEW_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)

    # Declare an array to hold the final list of different log file paths
    declare -a LOG_FILE_PATHS

    # Array to hold all rsyslog config entries
    RSYSLOG_CONFIGS=()
    RSYSLOG_CONFIGS=("${RSYSLOG_ETC_CONFIG}" "${RSYSLOG_INCLUDE_CONFIG[@]}" "${RSYSLOG_INCLUDE[@]}")

    # Get full list of files to be checked
    # RSYSLOG_CONFIGS may contain globs such as
    # /etc/rsyslog.d/*.conf /etc/rsyslog.d/*.frule
    # So, loop over the entries in RSYSLOG_CONFIGS and use find to get the list of included files.
    RSYSLOG_CONFIG_FILES=()
    for ENTRY in "${RSYSLOG_CONFIGS[@]}"
    do
    	# If directory, rsyslog will search for config files in recursively.
    	# However, files in hidden sub-directories or hidden files will be ignored.
    	if [ -d "${ENTRY}" ]
    	then
    		readarray -t FINDOUT < <(find "${ENTRY}" -not -path '*/.*' -type f)
    		RSYSLOG_CONFIG_FILES+=("${FINDOUT[@]}")
    	elif [ -f "${ENTRY}" ]
    	then
    		RSYSLOG_CONFIG_FILES+=("${ENTRY}")
    	else
    		echo "Invalid include object: ${ENTRY}"
    	fi
    done

    # Browse each file selected above as containing paths of log files
    # ('/etc/rsyslog.conf' and '/etc/rsyslog.d/*.conf' in the default configuration)
    for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
    do
    	# From each of these files extract just particular log file path(s), thus:
    	# * Ignore lines starting with space (' '), comment ('#"), or variable syntax ('$') characters,
    	# * Ignore empty lines,
    	# * Strip quotes and closing brackets from paths.
    	# * Ignore paths that match /dev|/etc.*\.conf, as those are paths, but likely not log files
    	# * From the remaining valid rows select only fields constituting a log file path
    	# Text file column is understood to represent a log file path if and only if all of the
    	# following are met:
    	# * it contains at least one slash '/' character,
    	# * it is preceded by space
    	# * it doesn't contain space (' '), colon (':'), and semicolon (';') characters
    	# Search log file for path(s) only in case it exists!
    	if [[ -f "${LOG_FILE}" ]]
    	then
    		NORMALIZED_CONFIG_FILE_LINES=$(sed -e "/^[#|$]/d" "${LOG_FILE}")
    		LINES_WITH_PATHS=$(grep '[^/]*\s\+\S*/\S\+$' <<< "${NORMALIZED_CONFIG_FILE_LINES}")
    		FILTERED_PATHS=$(awk '{if(NF>=2&&($NF~/^\//||$NF~/^-\//)){sub(/^-\//,"/",$NF);print $NF}}' <<< "${LINES_WITH_PATHS}")
    		CLEANED_PATHS=$(sed -e "s/[\"')]//g; /\\/etc.*\.conf/d; /\\/dev\\//d" <<< "${FILTERED_PATHS}")
    		MATCHED_ITEMS=$(sed -e "/^$/d" <<< "${CLEANED_PATHS}")
    		# Since above sed command might return more than one item (delimited by newline), split
    		# the particular matches entries into new array specific for this log file
    		readarray -t ARRAY_FOR_LOG_FILE <<< "$MATCHED_ITEMS"
    		# Concatenate the two arrays - previous content of $LOG_FILE_PATHS array with
    		# items from newly created array for this log file
    		LOG_FILE_PATHS+=("${ARRAY_FOR_LOG_FILE[@]}")
    		# Delete the temporary array
    		unset ARRAY_FOR_LOG_FILE
    	fi
    done

    # Check for RainerScript action log format which might be also multiline so grep regex is a bit
    # curly:
    # extract possibly multiline action omfile expressions
    # extract File="logfile" expression
    # match only "logfile" expression
    # exclude /dev/* paths (e.g., /dev/console)
    for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
    do
    	ACTION_OMFILE_LINES=$(grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" "${LOG_FILE}")
    	OMFILE_LINES=$(echo "${ACTION_OMFILE_LINES}"| grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)")
    	LOG_FILE_PATHS+=("$(echo "${OMFILE_LINES}"| grep -oE "\"([/[:alnum:][:punct:]]*)\""|tr -d "\"" | grep -v "^/dev/")")
    done

    # Ensure the correct attribute if file exists
    FILE_CMD="chgrp"
    for LOG_FILE_PATH in "${LOG_FILE_PATHS[@]}"
    do
    	# Sanity check - if particular $LOG_FILE_PATH is empty string, skip it from further processing
    	if [ -z "$LOG_FILE_PATH" ]
    	then
    		continue
    	fi
    	$FILE_CMD "root" "$LOG_FILE_PATH"
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_groupownership

    - name: Ensure Log Files Are Owned By Appropriate Group - Set rsyslog logfile configuration
        facts
      ansible.builtin.set_fact:
        rsyslog_etc_config: /etc/rsyslog.conf
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_groupownership

    - name: Ensure Log Files Are Owned By Appropriate Group - Get IncludeConfig directive
      ansible.builtin.shell: |
        set -o pipefail
        grep -e '$IncludeConfig' {{ rsyslog_etc_config }} | cut -d ' ' -f 2 || true
      register: rsyslog_old_inc
      changed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_groupownership

    - name: Ensure Log Files Are Owned By Appropriate Group - Get include files directives
      ansible.builtin.shell: |
        set -o pipefail
        awk '/)/{f=0} /include\(/{f=1} f{ nf=gensub("^(include\\(|\\s*)file=\"(\\S+)\".*","\\2",1); if($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
      register: rsyslog_new_inc
      changed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_groupownership

    - name: Ensure Log Files Are Owned By Appropriate Group - Aggregate rsyslog includes
      ansible.builtin.set_fact:
        include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
          }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      - rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_groupownership

    - name: Ensure Log Files Are Owned By Appropriate Group - List all config files
      ansible.builtin.find:
        paths: '{{ item | dirname }}'
        patterns: '{{ item | basename }}'
        hidden: false
        follow: true
      loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      - include_config_output is defined
      register: rsyslog_config_files
      failed_when: false
      changed_when: false
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_groupownership

    - name: Ensure Log Files Are Owned By Appropriate Group - Extract log files old format
      ansible.builtin.shell: |
        set -o pipefail
        grep -oP '^[^(\s|#|\$)]+[\s]*.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ item.1.path }} | \
        awk '{print $NF}' | \
        sed -e 's/^-//' || true
      loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
      register: log_files_old
      changed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      - rsyslog_config_files is not skipped
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_groupownership

    - name: Ensure Log Files Are Owned By Appropriate Group - Extract log files new format
      ansible.builtin.shell: |
        set -o pipefail
        grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
        grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
        grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
        tr -d "\"" | \
        grep -v '^/dev/' || true
      loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
      register: log_files_new
      changed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      - rsyslog_config_files is not skipped
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_groupownership

    - name: Ensure Log Files Are Owned By Appropriate Group - Sum all log files found
      ansible.builtin.set_fact:
        log_files: '{{ log_files_new.results | map(attribute=''stdout_lines'') | list
          | flatten | unique + log_files_old.results | map(attribute=''stdout_lines'')
          | list | flatten | unique }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_groupownership

    - name: Ensure Log Files Are Owned By Appropriate Group -Setup log files attribute
      ansible.builtin.file:
        path: '{{ item }}'
        group: root
        state: file
      loop: '{{ log_files | list | flatten | unique }}'
      failed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_groupownership
#### Rule Ensure Log Files Are Owned By Appropriate User [ref]
The owner of all log files written by `rsyslog` should be `root`. These log files are determined by the second part of each Rule line in `/etc/rsyslog.conf` and typically all appear in `/var/log`. For each log file LOGFILE referenced in `/etc/rsyslog.conf`, run the following command to inspect the file's owner:
    $ ls -l LOGFILE
If the owner is not `root`, run the following command to correct this:
    $ sudo chown root LOGFILE
Rationale: | The log files generated by rsyslog contain valuable information regarding system configuration, user authentication, and other such information. Log files should be protected from unauthorized access.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_rsyslog_files_ownership
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-10.5.1, Req-10.5.2
anssi | R71
cis | 5.1.3
ism | 0988, 1405
pcidss4 | 10.3.2, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && rpm --quiet -q rsyslog; then

    # List of log file paths to be inspected for correct permissions
    # * Primarily inspect log file paths listed in /etc/rsyslog.conf
    RSYSLOG_ETC_CONFIG="/etc/rsyslog.conf"
    # * And also the log file paths listed after rsyslog's $IncludeConfig directive
    #   (store the result into array for the case there's shell glob used as value of IncludeConfig)
    readarray -t OLD_INC < <(grep -e "\$IncludeConfig[[:space:]]\+[^[:space:];]\+" /etc/rsyslog.conf | cut -d ' ' -f 2)
    readarray -t RSYSLOG_INCLUDE_CONFIG < <(for INCPATH in "${OLD_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
    readarray -t NEW_INC < <(sed -n '/^\s*include(/,/)/Ip' /etc/rsyslog.conf | sed -n 's@.*file\s*=\s*"\([/[:alnum:][:punct:]]*\)".*@\1@Ip')
    readarray -t RSYSLOG_INCLUDE < <(for INCPATH in "${NEW_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)

    # Declare an array to hold the final list of different log file paths
    declare -a LOG_FILE_PATHS

    # Array to hold all rsyslog config entries
    RSYSLOG_CONFIGS=()
    RSYSLOG_CONFIGS=("${RSYSLOG_ETC_CONFIG}" "${RSYSLOG_INCLUDE_CONFIG[@]}" "${RSYSLOG_INCLUDE[@]}")

    # Get full list of files to be checked
    # RSYSLOG_CONFIGS may contain globs such as
    # /etc/rsyslog.d/*.conf /etc/rsyslog.d/*.frule
    # So, loop over the entries in RSYSLOG_CONFIGS and use find to get the list of included files.
    RSYSLOG_CONFIG_FILES=()
    for ENTRY in "${RSYSLOG_CONFIGS[@]}"
    do
    	# If directory, rsyslog will search for config files in recursively.
    	# However, files in hidden sub-directories or hidden files will be ignored.
    	if [ -d "${ENTRY}" ]
    	then
    		readarray -t FINDOUT < <(find "${ENTRY}" -not -path '*/.*' -type f)
    		RSYSLOG_CONFIG_FILES+=("${FINDOUT[@]}")
    	elif [ -f "${ENTRY}" ]
    	then
    		RSYSLOG_CONFIG_FILES+=("${ENTRY}")
    	else
    		echo "Invalid include object: ${ENTRY}"
    	fi
    done

    # Browse each file selected above as containing paths of log files
    # ('/etc/rsyslog.conf' and '/etc/rsyslog.d/*.conf' in the default configuration)
    for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
    do
    	# From each of these files extract just particular log file path(s), thus:
    	# * Ignore lines starting with space (' '), comment ('#"), or variable syntax ('$') characters,
    	# * Ignore empty lines,
    	# * Strip quotes and closing brackets from paths.
    	# * Ignore paths that match /dev|/etc.*\.conf, as those are paths, but likely not log files
    	# * From the remaining valid rows select only fields constituting a log file path
    	# Text file column is understood to represent a log file path if and only if all of the
    	# following are met:
    	# * it contains at least one slash '/' character,
    	# * it is preceded by space
    	# * it doesn't contain space (' '), colon (':'), and semicolon (';') characters
    	# Search log file for path(s) only in case it exists!
    	if [[ -f "${LOG_FILE}" ]]
    	then
    		NORMALIZED_CONFIG_FILE_LINES=$(sed -e "/^[#|$]/d" "${LOG_FILE}")
    		LINES_WITH_PATHS=$(grep '[^/]*\s\+\S*/\S\+$' <<< "${NORMALIZED_CONFIG_FILE_LINES}")
    		FILTERED_PATHS=$(awk '{if(NF>=2&&($NF~/^\//||$NF~/^-\//)){sub(/^-\//,"/",$NF);print $NF}}' <<< "${LINES_WITH_PATHS}")
    		CLEANED_PATHS=$(sed -e "s/[\"')]//g; /\\/etc.*\.conf/d; /\\/dev\\//d" <<< "${FILTERED_PATHS}")
    		MATCHED_ITEMS=$(sed -e "/^$/d" <<< "${CLEANED_PATHS}")
    		# Since above sed command might return more than one item (delimited by newline), split
    		# the particular matches entries into new array specific for this log file
    		readarray -t ARRAY_FOR_LOG_FILE <<< "$MATCHED_ITEMS"
    		# Concatenate the two arrays - previous content of $LOG_FILE_PATHS array with
    		# items from newly created array for this log file
    		LOG_FILE_PATHS+=("${ARRAY_FOR_LOG_FILE[@]}")
    		# Delete the temporary array
    		unset ARRAY_FOR_LOG_FILE
    	fi
    done

    # Check for RainerScript action log format which might be also multiline so grep regex is a bit
    # curly:
    # extract possibly multiline action omfile expressions
    # extract File="logfile" expression
    # match only "logfile" expression
    # exclude /dev/* paths (e.g., /dev/console)
    for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
    do
    	ACTION_OMFILE_LINES=$(grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" "${LOG_FILE}")
    	OMFILE_LINES=$(echo "${ACTION_OMFILE_LINES}"| grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)")
    	LOG_FILE_PATHS+=("$(echo "${OMFILE_LINES}"| grep -oE "\"([/[:alnum:][:punct:]]*)\""|tr -d "\"" | grep -v "^/dev/")")
    done

    # Ensure the correct attribute if file exists
    FILE_CMD="chown"
    for LOG_FILE_PATH in "${LOG_FILE_PATHS[@]}"
    do
    	# Sanity check - if particular $LOG_FILE_PATH is empty string, skip it from further processing
    	if [ -z "$LOG_FILE_PATH" ]
    	then
    		continue
    	fi
    	$FILE_CMD "root" "$LOG_FILE_PATH"
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_ownership

    - name: Ensure Log Files Are Owned By Appropriate User - Set rsyslog logfile configuration
        facts
      ansible.builtin.set_fact:
        rsyslog_etc_config: /etc/rsyslog.conf
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_ownership

    - name: Ensure Log Files Are Owned By Appropriate User - Get IncludeConfig directive
      ansible.builtin.shell: |
        set -o pipefail
        grep -e '$IncludeConfig' {{ rsyslog_etc_config }} | cut -d ' ' -f 2 || true
      register: rsyslog_old_inc
      changed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_ownership

    - name: Ensure Log Files Are Owned By Appropriate User - Get include files directives
      ansible.builtin.shell: |
        set -o pipefail
        awk '/)/{f=0} /include\(/{f=1} f{ nf=gensub("^(include\\(|\\s*)file=\"(\\S+)\".*","\\2",1); if($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
      register: rsyslog_new_inc
      changed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_ownership

    - name: Ensure Log Files Are Owned By Appropriate User - Aggregate rsyslog includes
      ansible.builtin.set_fact:
        include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
          }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      - rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_ownership

    - name: Ensure Log Files Are Owned By Appropriate User - List all config files
      ansible.builtin.find:
        paths: '{{ item | dirname }}'
        patterns: '{{ item | basename }}'
        hidden: false
        follow: true
      loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      - include_config_output is defined
      register: rsyslog_config_files
      failed_when: false
      changed_when: false
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_ownership

    - name: Ensure Log Files Are Owned By Appropriate User - Extract log files old format
      ansible.builtin.shell: |
        set -o pipefail
        grep -oP '^[^(\s|#|\$)]+[\s]*.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ item.1.path }} | \
        awk '{print $NF}' | \
        sed -e 's/^-//' || true
      loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
      register: log_files_old
      changed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      - rsyslog_config_files is not skipped
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_ownership

    - name: Ensure Log Files Are Owned By Appropriate User - Extract log files new format
      ansible.builtin.shell: |
        set -o pipefail
        grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
        grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
        grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
        tr -d "\"" | \
        grep -v '^/dev/' || true
      loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
      register: log_files_new
      changed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      - rsyslog_config_files is not skipped
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_ownership

    - name: Ensure Log Files Are Owned By Appropriate User - Sum all log files found
      ansible.builtin.set_fact:
        log_files: '{{ log_files_new.results | map(attribute=''stdout_lines'') | list
          | flatten | unique + log_files_old.results | map(attribute=''stdout_lines'')
          | list | flatten | unique }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_ownership

    - name: Ensure Log Files Are Owned By Appropriate User -Setup log files attribute
      ansible.builtin.file:
        path: '{{ item }}'
        owner: root
        state: file
      loop: '{{ log_files | list | flatten | unique }}'
      failed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_ownership
#### Rule Ensure System Log Files Have Correct Permissions [ref]
The file permissions for all log files written by `rsyslog` should be set to 640, or more restrictive. These log files are determined by the second part of each Rule line in `/etc/rsyslog.conf` and typically all appear in `/var/log`. For each log file LOGFILE referenced in `/etc/rsyslog.conf`, run the following command to inspect the file's permissions:
    $ ls -l LOGFILE
If the permissions are not 640 or more restrictive, run the following command to correct this:
    $ sudo chmod 640 LOGFILE
"
Rationale: | Log files can contain valuable information regarding system configuration. If the system log files are not protected unauthorized users could change the logged data, eliminating their forensic value.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_rsyslog_files_permissions
References: |
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
pcidss | Req-10.5.1, Req-10.5.2
anssi | R71
cis | 5.1.3
ism | 0988, 1405
pcidss4 | 10.3.1, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && rpm --quiet -q rsyslog; then

    # List of log file paths to be inspected for correct permissions
    # * Primarily inspect log file paths listed in /etc/rsyslog.conf
    RSYSLOG_ETC_CONFIG="/etc/rsyslog.conf"
    # * And also the log file paths listed after rsyslog's $IncludeConfig directive
    #   (store the result into array for the case there's shell glob used as value of IncludeConfig)
    readarray -t OLD_INC < <(grep -e "\$IncludeConfig[[:space:]]\+[^[:space:];]\+" /etc/rsyslog.conf | cut -d ' ' -f 2)
    readarray -t RSYSLOG_INCLUDE_CONFIG < <(for INCPATH in "${OLD_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)
    readarray -t NEW_INC < <(sed -n '/^\s*include(/,/)/Ip' /etc/rsyslog.conf | sed -n 's@.*file\s*=\s*"\([/[:alnum:][:punct:]]*\)".*@\1@Ip')
    readarray -t RSYSLOG_INCLUDE < <(for INCPATH in "${NEW_INC[@]}"; do eval printf '%s\\n' "${INCPATH}"; done)

    # Declare an array to hold the final list of different log file paths
    declare -a LOG_FILE_PATHS

    # Array to hold all rsyslog config entries
    RSYSLOG_CONFIGS=()
    RSYSLOG_CONFIGS=("${RSYSLOG_ETC_CONFIG}" "${RSYSLOG_INCLUDE_CONFIG[@]}" "${RSYSLOG_INCLUDE[@]}")

    # Get full list of files to be checked
    # RSYSLOG_CONFIGS may contain globs such as
    # /etc/rsyslog.d/*.conf /etc/rsyslog.d/*.frule
    # So, loop over the entries in RSYSLOG_CONFIGS and use find to get the list of included files.
    RSYSLOG_CONFIG_FILES=()
    for ENTRY in "${RSYSLOG_CONFIGS[@]}"
    do
    	# If directory, rsyslog will search for config files in recursively.
    	# However, files in hidden sub-directories or hidden files will be ignored.
    	if [ -d "${ENTRY}" ]
    	then
    		readarray -t FINDOUT < <(find "${ENTRY}" -not -path '*/.*' -type f)
    		RSYSLOG_CONFIG_FILES+=("${FINDOUT[@]}")
    	elif [ -f "${ENTRY}" ]
    	then
    		RSYSLOG_CONFIG_FILES+=("${ENTRY}")
    	else
    		echo "Invalid include object: ${ENTRY}"
    	fi
    done

    # Browse each file selected above as containing paths of log files
    # ('/etc/rsyslog.conf' and '/etc/rsyslog.d/*.conf' in the default configuration)
    for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
    do
    	# From each of these files extract just particular log file path(s), thus:
    	# * Ignore lines starting with space (' '), comment ('#"), or variable syntax ('$') characters,
    	# * Ignore empty lines,
    	# * Strip quotes and closing brackets from paths.
    	# * Ignore paths that match /dev|/etc.*\.conf, as those are paths, but likely not log files
    	# * From the remaining valid rows select only fields constituting a log file path
    	# Text file column is understood to represent a log file path if and only if all of the
    	# following are met:
    	# * it contains at least one slash '/' character,
    	# * it is preceded by space
    	# * it doesn't contain space (' '), colon (':'), and semicolon (';') characters
    	# Search log file for path(s) only in case it exists!
    	if [[ -f "${LOG_FILE}" ]]
    	then
    		NORMALIZED_CONFIG_FILE_LINES=$(sed -e "/^[#|$]/d" "${LOG_FILE}")
    		LINES_WITH_PATHS=$(grep '[^/]*\s\+\S*/\S\+$' <<< "${NORMALIZED_CONFIG_FILE_LINES}")
    		FILTERED_PATHS=$(awk '{if(NF>=2&&($NF~/^\//||$NF~/^-\//)){sub(/^-\//,"/",$NF);print $NF}}' <<< "${LINES_WITH_PATHS}")
    		CLEANED_PATHS=$(sed -e "s/[\"')]//g; /\\/etc.*\.conf/d; /\\/dev\\//d" <<< "${FILTERED_PATHS}")
    		MATCHED_ITEMS=$(sed -e "/^$/d" <<< "${CLEANED_PATHS}")
    		# Since above sed command might return more than one item (delimited by newline), split
    		# the particular matches entries into new array specific for this log file
    		readarray -t ARRAY_FOR_LOG_FILE <<< "$MATCHED_ITEMS"
    		# Concatenate the two arrays - previous content of $LOG_FILE_PATHS array with
    		# items from newly created array for this log file
    		LOG_FILE_PATHS+=("${ARRAY_FOR_LOG_FILE[@]}")
    		# Delete the temporary array
    		unset ARRAY_FOR_LOG_FILE
    	fi
    done

    # Check for RainerScript action log format which might be also multiline so grep regex is a bit
    # curly:
    # extract possibly multiline action omfile expressions
    # extract File="logfile" expression
    # match only "logfile" expression
    # exclude /dev/* paths (e.g., /dev/console)
    for LOG_FILE in "${RSYSLOG_CONFIG_FILES[@]}"
    do
    	ACTION_OMFILE_LINES=$(grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" "${LOG_FILE}")
    	OMFILE_LINES=$(echo "${ACTION_OMFILE_LINES}"| grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)")
    	LOG_FILE_PATHS+=("$(echo "${OMFILE_LINES}"| grep -oE "\"([/[:alnum:][:punct:]]*)\""|tr -d "\"" | grep -v "^/dev/")")
    done

    # Ensure the correct attribute if file exists
    FILE_CMD="chmod"
    for LOG_FILE_PATH in "${LOG_FILE_PATHS[@]}"
    do
    	# Sanity check - if particular $LOG_FILE_PATH is empty string, skip it from further processing
    	if [ -z "$LOG_FILE_PATH" ]
    	then
    		continue
    	fi
    	$FILE_CMD "0640" "$LOG_FILE_PATH"
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_permissions

    - name: Ensure System Log Files Have Correct Permissions - Set rsyslog logfile configuration
        facts
      ansible.builtin.set_fact:
        rsyslog_etc_config: /etc/rsyslog.conf
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_permissions

    - name: Ensure System Log Files Have Correct Permissions - Get IncludeConfig directive
      ansible.builtin.shell: |
        set -o pipefail
        grep -e '$IncludeConfig' {{ rsyslog_etc_config }} | cut -d ' ' -f 2 || true
      register: rsyslog_old_inc
      changed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_permissions

    - name: Ensure System Log Files Have Correct Permissions - Get include files directives
      ansible.builtin.shell: |
        set -o pipefail
        awk '/)/{f=0} /include\(/{f=1} f{ nf=gensub("^(include\\(|\\s*)file=\"(\\S+)\".*","\\2",1); if($0!=nf){ print nf }}' {{ rsyslog_etc_config }} || true
      register: rsyslog_new_inc
      changed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_permissions

    - name: Ensure System Log Files Have Correct Permissions - Aggregate rsyslog includes
      ansible.builtin.set_fact:
        include_config_output: '{{ rsyslog_old_inc.stdout_lines + rsyslog_new_inc.stdout_lines
          }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      - rsyslog_old_inc is not skipped and rsyslog_new_inc is not skipped
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_permissions

    - name: Ensure System Log Files Have Correct Permissions - List all config files
      ansible.builtin.find:
        paths: '{{ item | dirname }}'
        patterns: '{{ item | basename }}'
        hidden: false
        follow: true
      loop: '{{ include_config_output | list + [rsyslog_etc_config] }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      - include_config_output is defined
      register: rsyslog_config_files
      failed_when: false
      changed_when: false
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_permissions

    - name: Ensure System Log Files Have Correct Permissions - Extract log files old format
      ansible.builtin.shell: |
        set -o pipefail
        grep -oP '^[^(\s|#|\$)]+[\s]*.*[\s]+-?(/+[^:;\s]+);*\.*$' {{ item.1.path }} | \
        awk '{print $NF}' | \
        sed -e 's/^-//' || true
      loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
      register: log_files_old
      changed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      - rsyslog_config_files is not skipped
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_permissions

    - name: Ensure System Log Files Have Correct Permissions - Extract log files new format
      ansible.builtin.shell: |
        set -o pipefail
        grep -iozP "action\s*\(\s*type\s*=\s*\"omfile\"[^\)]*\)" {{ item.1.path }} | \
        grep -iaoP "\bFile\s*=\s*\"([/[:alnum:][:punct:]]*)\"\s*\)" | \
        grep -oE "\"([/[:alnum:][:punct:]]*)\"" | \
        tr -d "\"" | \
        grep -v '^/dev/' || true
      loop: '{{ rsyslog_config_files.results | default([]) | subelements(''files'') }}'
      register: log_files_new
      changed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      - rsyslog_config_files is not skipped
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_permissions

    - name: Ensure System Log Files Have Correct Permissions - Sum all log files found
      ansible.builtin.set_fact:
        log_files: '{{ log_files_new.results | map(attribute=''stdout_lines'') | list
          | flatten | unique + log_files_old.results | map(attribute=''stdout_lines'')
          | list | flatten | unique }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_permissions

    - name: Ensure System Log Files Have Correct Permissions -Setup log files attribute
      ansible.builtin.file:
        path: '{{ item }}'
        mode: '0640'
        state: file
      loop: '{{ log_files | list | flatten | unique }}'
      failed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"rsyslog" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.1
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - configure_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_files_permissions
Group systemd-journald Group contains 5 rules
[ref] systemd-journald is a system service that collects and stores logging data. It creates and maintains structured, indexed journals based on logging information that is received from a variety of sources. For more information on `systemd-journald` and additional `systemd-journald` configuration options, see https://systemd.io/.
#### Rule Enable systemd-journald Service [ref]
The `systemd-journald` service is an essential component of systemd. The `systemd-journald` service can be enabled with the following command:
    $ sudo systemctl enable systemd-journald.service
Rationale: | In the event of a system failure, Amazon Linux 2023 must preserve any information necessary to determine cause of failure and any information necessary to return to operations with least disruption to system processes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_service_systemd-journald_enabled
References: |
nist | SC-24
os-srg | SRG-OS-000269-GPOS-00103
cis | 5.1.2.2
Remediation OSBuild Blueprint snippet ⇲
    [customizations.services]
    enabled = ["systemd-journald"]
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    SYSTEMCTL_EXEC='/usr/bin/systemctl'
    "$SYSTEMCTL_EXEC" unmask 'systemd-journald.service'
    if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
      "$SYSTEMCTL_EXEC" start 'systemd-journald.service'
    fi
    "$SYSTEMCTL_EXEC" enable 'systemd-journald.service'

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-SC-24
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_systemd-journald_enabled

    - name: Enable systemd-journald Service - Enable service systemd-journald
      block:

      - name: Gather the package facts
        ansible.builtin.package_facts:
          manager: auto

      - name: Enable systemd-journald Service - Enable Service systemd-journald
        ansible.builtin.systemd:
          name: systemd-journald
          enabled: true
          state: started
          masked: false
        when:
        - '"systemd" in ansible_facts.packages'
      tags:
      - NIST-800-53-SC-24
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_systemd-journald_enabled
      - special_service_block
      when: '"kernel" in ansible_facts.packages'
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include enable_systemd-journald

    class enable_systemd-journald {
      service {'systemd-journald':
        enable => true,
        ensure => 'running',
      }
    }
#### Rule Ensure journald is configured to compress large log files [ref]
The journald system can compress large log files to avoid fill the system disk.
Rationale: | Log files that are not properly compressed run the risk of growing so large that they fill up the log partition. Valuable logging information could be lost if the log partition becomes full.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_journald_compress
References: |
cis | 5.1.2.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if [ -e "/etc/systemd/journald.conf" ] ; then

        LC_ALL=C sed -i "/^\s*Compress\s*=\s*/d" "/etc/systemd/journald.conf"
    else
        touch "/etc/systemd/journald.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/systemd/journald.conf"

    cp "/etc/systemd/journald.conf" "/etc/systemd/journald.conf.bak"
    # Insert before the line matching the regex '^#\s*Compress'.
    line_number="$(LC_ALL=C grep -n "^#\s*Compress" "/etc/systemd/journald.conf.bak" | LC_ALL=C sed 's/:.*//g')"
    if [ -z "$line_number" ]; then
        # There was no match of '^#\s*Compress', insert at
        # the end of the file.
        printf '%s\n' "Compress=yes" >> "/etc/systemd/journald.conf"
    else
        head -n "$(( line_number - 1 ))" "/etc/systemd/journald.conf.bak" > "/etc/systemd/journald.conf"
        printf '%s\n' "Compress=yes" >> "/etc/systemd/journald.conf"
        tail -n "+$(( line_number ))" "/etc/systemd/journald.conf.bak" >> "/etc/systemd/journald.conf"
    fi
    # Clean up after ourselves.
    rm "/etc/systemd/journald.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - journald_compress
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Setting unquoted shell-style assignment of 'Compress' to 'yes' in '/etc/systemd/journald.conf'
      block:

      - name: Check for duplicate values
        ansible.builtin.lineinfile:
          path: /etc/systemd/journald.conf
          create: true
          regexp: (?i)^\s*Compress=
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/systemd/journald.conf
        ansible.builtin.lineinfile:
          path: /etc/systemd/journald.conf
          create: true
          regexp: (?i)^\s*Compress=
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/systemd/journald.conf
        ansible.builtin.lineinfile:
          path: /etc/systemd/journald.conf
          create: true
          regexp: (?i)^\s*Compress=
          line: Compress=yes
          state: present
          insertbefore: ^# Compress
          validate: /usr/bin/bash -n %s
      when: '"kernel" in ansible_facts.packages'
      tags:
      - journald_compress
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure journald is configured to send logs to rsyslog [ref]
Data from journald may be stored in volatile memory or persisted locally. Utilities exist to accept remote export of journald logs.
Rationale: | Storing log data on a remote host protects log integrity from local attacks. If an attacker gains root access on the local system, they could tamper with or remove log data that is stored on the local system.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_journald_forward_to_syslog
References: |
cis | 5.1.1.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if [ -e "/etc/systemd/journald.conf" ] ; then

        LC_ALL=C sed -i "/^\s*ForwardToSyslog\s*=\s*/d" "/etc/systemd/journald.conf"
    else
        touch "/etc/systemd/journald.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/systemd/journald.conf"

    cp "/etc/systemd/journald.conf" "/etc/systemd/journald.conf.bak"
    # Insert before the line matching the regex '^#\s*ForwardToSyslog'.
    line_number="$(LC_ALL=C grep -n "^#\s*ForwardToSyslog" "/etc/systemd/journald.conf.bak" | LC_ALL=C sed 's/:.*//g')"
    if [ -z "$line_number" ]; then
        # There was no match of '^#\s*ForwardToSyslog', insert at
        # the end of the file.
        printf '%s\n' "ForwardToSyslog=yes" >> "/etc/systemd/journald.conf"
    else
        head -n "$(( line_number - 1 ))" "/etc/systemd/journald.conf.bak" > "/etc/systemd/journald.conf"
        printf '%s\n' "ForwardToSyslog=yes" >> "/etc/systemd/journald.conf"
        tail -n "+$(( line_number ))" "/etc/systemd/journald.conf.bak" >> "/etc/systemd/journald.conf"
    fi
    # Clean up after ourselves.
    rm "/etc/systemd/journald.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - journald_forward_to_syslog
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Setting unquoted shell-style assignment of 'ForwardToSyslog' to 'yes' in '/etc/systemd/journald.conf'
      block:

      - name: Check for duplicate values
        ansible.builtin.lineinfile:
          path: /etc/systemd/journald.conf
          create: true
          regexp: (?i)^\s*ForwardToSyslog=
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/systemd/journald.conf
        ansible.builtin.lineinfile:
          path: /etc/systemd/journald.conf
          create: true
          regexp: (?i)^\s*ForwardToSyslog=
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/systemd/journald.conf
        ansible.builtin.lineinfile:
          path: /etc/systemd/journald.conf
          create: true
          regexp: (?i)^\s*ForwardToSyslog=
          line: ForwardToSyslog=yes
          state: present
          insertbefore: ^# ForwardToSyslog
          validate: /usr/bin/bash -n %s
      when: '"kernel" in ansible_facts.packages'
      tags:
      - journald_forward_to_syslog
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure journald is configured to write log files to persistent disk [ref]
The journald system may store log files in volatile memory or locally on disk. If the logs are only stored in volatile memory they will be lost upon reboot.
Rationale: | Log files contain valuable data and need to be persistent to aid in possible investigations.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_journald_storage
References: |
cis | 5.1.2.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if [ -e "/etc/systemd/journald.conf" ] ; then

        LC_ALL=C sed -i "/^\s*Storage\s*=\s*/d" "/etc/systemd/journald.conf"
    else
        touch "/etc/systemd/journald.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/systemd/journald.conf"

    cp "/etc/systemd/journald.conf" "/etc/systemd/journald.conf.bak"
    # Insert before the line matching the regex '^#\s*Storage'.
    line_number="$(LC_ALL=C grep -n "^#\s*Storage" "/etc/systemd/journald.conf.bak" | LC_ALL=C sed 's/:.*//g')"
    if [ -z "$line_number" ]; then
        # There was no match of '^#\s*Storage', insert at
        # the end of the file.
        printf '%s\n' "Storage=persistent" >> "/etc/systemd/journald.conf"
    else
        head -n "$(( line_number - 1 ))" "/etc/systemd/journald.conf.bak" > "/etc/systemd/journald.conf"
        printf '%s\n' "Storage=persistent" >> "/etc/systemd/journald.conf"
        tail -n "+$(( line_number ))" "/etc/systemd/journald.conf.bak" >> "/etc/systemd/journald.conf"
    fi
    # Clean up after ourselves.
    rm "/etc/systemd/journald.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - journald_storage
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Setting unquoted shell-style assignment of 'Storage' to 'persistent' in '/etc/systemd/journald.conf'
      block:

      - name: Check for duplicate values
        ansible.builtin.lineinfile:
          path: /etc/systemd/journald.conf
          create: true
          regexp: (?i)^\s*Storage=
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/systemd/journald.conf
        ansible.builtin.lineinfile:
          path: /etc/systemd/journald.conf
          create: true
          regexp: (?i)^\s*Storage=
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/systemd/journald.conf
        ansible.builtin.lineinfile:
          path: /etc/systemd/journald.conf
          create: true
          regexp: (?i)^\s*Storage=
          line: Storage=persistent
          state: present
          insertbefore: ^# Storage
          validate: /usr/bin/bash -n %s
      when: '"kernel" in ansible_facts.packages'
      tags:
      - journald_storage
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Disable systemd-journal-remote Socket [ref]
Journald supports the ability to receive messages from remote hosts, thus acting as a log server. Clients should not receive data from other hosts. NOTE: The same package, systemd-journal-remote , is used for both sending logs to remote hosts and receiving incoming logs. With regards to receiving logs, there are two Systemd unit files; systemd-journal-remote.socket and systemd-journal-remote.service.
Rationale: | If a client is configured to also receive data, thus turning it into a server, the client system is acting outside it's operational boundary.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_socket_systemd-journal-remote_disabled
References: |
cis | 5.1.2.1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    SOCKET_NAME="systemd-journal-remote.socket"
    SYSTEMCTL_EXEC='/usr/bin/systemctl'

    if "$SYSTEMCTL_EXEC" -q list-unit-files --type socket | grep -q "$SOCKET_NAME"; then
        if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
          "$SYSTEMCTL_EXEC" stop "$SOCKET_NAME"
        fi
        "$SYSTEMCTL_EXEC" mask "$SOCKET_NAME"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - socket_systemd-journal-remote_disabled

    - name: Disable systemd-journal-remote Socket - Collect systemd Socket Units Present
        in the System
      ansible.builtin.command:
        cmd: systemctl -q list-unit-files --type socket
      register: result_systemd_unit_files
      changed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - socket_systemd-journal-remote_disabled

    - name: Disable systemd-journal-remote Socket - Ensure systemd-journal-remote.socket
        is Masked
      ansible.builtin.systemd:
        name: systemd-journal-remote.socket
        state: stopped
        enabled: false
        masked: true
      when:
      - '"kernel" in ansible_facts.packages'
      - result_systemd_unit_files.stdout_lines is search("systemd-journal-remote.socket")
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - socket_systemd-journal-remote_disabled
Group Configure rsyslogd to Accept Remote Messages If Acting as a Log Server Group contains 1 rule
[ref] By default, `rsyslog` does not listen over the network for log messages. If needed, modules can be enabled to allow the rsyslog daemon to receive messages from other systems and for the system thus to act as a log server. If the system is not a log server, then lines concerning these modules should remain commented out.
#### Rule Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server [ref]
The `rsyslog` daemon should not accept remote messages unless the system acts as a log server. To ensure that it is not listening on the network, ensure any of the following lines are not found in `rsyslog` configuration files. If using legacy syntax:
    $ModLoad imtcp
    $InputTCPServerRun port
    $ModLoad imudp
    $UDPServerRun port
    $ModLoad imrelp
    $InputRELPServerRun port
If using RainerScript syntax:
    module(load="imtcp")
    module(load="imudp")
    input(type="imtcp" port="514")
    input(type="imudp" port="514")
Rationale: | Any process which receives messages from the network incurs some risk of receiving malicious messages. This risk can be eliminated for rsyslog by configuring it not to listen on the network.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_rsyslog_nolisten
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9
cobit5 | APO01.06, APO11.04, APO13.01, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02, MEA02.01
isa-62443-2009 | 4.2.3.4, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.8, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3
isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.5.1, A.12.6.2, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.IP-1, PR.PT-1, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
cis | 5.1.1.7
ism | 0988, 1405
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    legacy_regex='^\s*\$(((Input(TCP|RELP)|UDP)ServerRun)|ModLoad\s+(imtcp|imudp|imrelp))'
    rainer_regex='^\s*(module|input)\((load|type)="(imtcp|imudp)".*$'

    readarray -t legacy_targets < <(grep -l -E -r "${legacy_regex[@]}" /etc/rsyslog.conf /etc/rsyslog.d/)
    readarray -t rainer_targets < <(grep -l -E -r "${rainer_regex[@]}" /etc/rsyslog.conf /etc/rsyslog.d/)

    config_changed=false
    if [ ${#legacy_targets[@]} -gt 0 ]; then
        for target in "${legacy_targets[@]}"; do
            sed -E -i "/$legacy_regex/ s/^/# /" "$target"
        done
        config_changed=true
    fi

    if [ ${#rainer_targets[@]} -gt 0 ]; then
        for target in "${rainer_targets[@]}"; do
            sed -E -i "/$rainer_regex/ s/^/# /" "$target"
        done
        config_changed=true
    fi

    if $config_changed; then
        systemctl restart rsyslog.service
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_nolisten

    - name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
        - Define Rsyslog Config Lines Regex in Legacy Syntax
      ansible.builtin.set_fact:
        rsyslog_listen_legacy_regex: ^\s*\$(((Input(TCP|RELP)|UDP)ServerRun)|ModLoad\s+(imtcp|imudp|imrelp))
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_nolisten

    - name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
        - Search for Legacy Config Lines in Rsyslog Main Config File
      ansible.builtin.find:
        paths: /etc
        pattern: rsyslog.conf
        contains: '{{ rsyslog_listen_legacy_regex }}'
      register: rsyslog_listen_legacy_main_file
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_nolisten

    - name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
        - Search for Legacy Config Lines in Rsyslog Include Files
      ansible.builtin.find:
        paths: /etc/rsyslog.d/
        pattern: '*.conf'
        contains: '{{ rsyslog_listen_legacy_regex }}'
      register: rsyslog_listen_legacy_include_files
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_nolisten

    - name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
        - Assemble List of Config Files With Listen Lines in Legacy Syntax
      ansible.builtin.set_fact:
        rsyslog_legacy_remote_listen_files: '{{ rsyslog_listen_legacy_main_file.files
          | map(attribute=''path'') | list + rsyslog_listen_legacy_include_files.files
          | map(attribute=''path'') | list }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_nolisten

    - name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
        - Comment Listen Config Lines Wherever Defined Using Legacy Syntax
      ansible.builtin.replace:
        path: '{{ item }}'
        regexp: '{{ rsyslog_listen_legacy_regex }}'
        replace: '# \1'
      loop: '{{ rsyslog_legacy_remote_listen_files }}'
      register: rsyslog_listen_legacy_comment
      when:
      - '"kernel" in ansible_facts.packages'
      - rsyslog_legacy_remote_listen_files | length > 0
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_nolisten

    - name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
        - Define Rsyslog Config Lines Regex in RainerScript Syntax
      ansible.builtin.set_fact:
        rsyslog_listen_rainer_regex: ^\s*(module|input)\((load|type)="(imtcp|imudp)".*$
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_nolisten

    - name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
        - Search for RainerScript Config Lines in Rsyslog Main Config File
      ansible.builtin.find:
        paths: /etc
        pattern: rsyslog.conf
        contains: '{{ rsyslog_listen_rainer_regex }}'
      register: rsyslog_rainer_remote_main_file
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_nolisten

    - name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
        - Search for RainerScript Config Lines in Rsyslog Include Files
      ansible.builtin.find:
        paths: /etc/rsyslog.d/
        pattern: '*.conf'
        contains: '{{ rsyslog_listen_rainer_regex }}'
      register: rsyslog_rainer_remote_include_files
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_nolisten

    - name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
        - Assemble List of Config Files With Listen Lines in RainerScript
      ansible.builtin.set_fact:
        rsyslog_rainer_remote_listen_files: '{{ rsyslog_rainer_remote_main_file.files
          | map(attribute=''path'') | list + rsyslog_rainer_remote_include_files.files
          | map(attribute=''path'') | list }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_nolisten

    - name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
        - Comment Listen Config Lines Wherever Defined Using RainerScript
      ansible.builtin.replace:
        path: '{{ item }}'
        regexp: '{{ rsyslog_listen_rainer_regex }}'
        replace: '# \1'
      loop: '{{ rsyslog_rainer_remote_listen_files }}'
      register: rsyslog_listen_rainer_comment
      when:
      - '"kernel" in ansible_facts.packages'
      - rsyslog_rainer_remote_listen_files | length > 0
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_nolisten

    - name: Ensure rsyslog Does Not Accept Remote Messages Unless Acting As Log Server
        - Restart Rsyslog if Any Line Were Commented Out
      ansible.builtin.service:
        name: rsyslog
        state: restarted
      when:
      - '"kernel" in ansible_facts.packages'
      - rsyslog_listen_legacy_comment is changed or rsyslog_listen_rainer_comment is changed
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_nolisten
Group Rsyslog Logs Sent To Remote Host Group contains 1 rule
[ref] If system logs are to be useful in detecting malicious activities, it is necessary to send logs to a remote server. An intruder who has compromised the root account on a system may delete the log entries which indicate that the system was attacked before they are seen by an administrator. However, it is recommended that logs be stored on the local host in addition to being sent to the loghost, especially if `rsyslog` has been configured to use the UDP protocol to send messages over a network. UDP does not guarantee reliable delivery, and moderately busy sites will lose log messages occasionally, especially in periods of high traffic which may be the result of an attack. In addition, remote `rsyslog` messages are not authenticated in any way by default, so it is easy for an attacker to introduce spurious messages to the central log server. Also, some problems cause loss of network connectivity, which will prevent the sending of messages to the central server. For all of these reasons, it is better to store log messages both centrally and on each host, so that they can be correlated if necessary.
#### Rule Ensure Logs Sent To Remote Host [ref]
To configure rsyslog to send logs to a remote log server, open `/etc/rsyslog.conf` and read and understand the last section of the file, which describes the multiple directives necessary to activate remote logging. Along with these other directives, the system can be configured to forward its logs to a particular log server by adding or correcting one of the following lines, substituting `logcollector` appropriately. The choice of protocol depends on the environment of the system; although TCP and RELP provide more reliable message delivery, they may not be supported in all environments. To use UDP for log message delivery:
    *.* @logcollector
Or in RainerScript:
    *.* action(type="omfwd" ... target="logcollector" protocol="udp")
To use TCP for log message delivery:
    *.* @@logcollector
Or in RainerScript:
    *.* action(type="omfwd" ... target="logcollector" protocol="tcp")
To use RELP for log message delivery:
    *.* :omrelp:logcollector
Or in RainerScript:
    *.* action(type="omfwd" ... target="logcollector" protocol="relp")
There must be a resolvable DNS CNAME or Alias record set to "logcollector" for logs to be sent correctly to the centralized logging utility. Warning: It is important to configure queues in case the client is sending log messages to a remote server. If queues are not configured, the system will stop functioning when the connection to the remote server is not available. Please consult Rsyslog documentation for more information about configuration of queues. The example configuration which should go into `/etc/rsyslog.conf` can look like the following lines:
    $ActionQueueType LinkedList
    $ActionQueueFileName queuefilename
    $ActionQueueMaxDiskSpace 1g
    $ActionQueueSaveOnShutdown on
    $ActionResumeRetryCount -1
Or if using Rainer Script syntax, it could be:
    *.* action(type="omfwd" queue.type="linkedlist" queue.filename="example_fwd" action.resumeRetryCount="-1" queue.saveOnShutdown="on" target="example.com" port="30514" protocol="tcp")
Rationale: | A log server (loghost) receives syslog messages from one or more systems. This data can be used as an additional log source in the event a system is compromised and its local logs are suspect. Forwarding log messages to a remote loghost also provides system administrators with a centralized place to view the status of multiple hosts within the enterprise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_rsyslog_remote_loghost
References: |
cis-csc | 1, 13, 14, 15, 16, 2, 3, 5, 6
cobit5 | APO11.04, APO13.01, BAI03.05, BAI04.04, DSS05.04, DSS05.07, MEA02.01
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(B), 164.308(a)(5)(ii)(C), 164.308(a)(6)(ii), 164.308(a)(8), 164.310(d)(2)(iii), 164.312(b), 164.314(a)(2)(i)(C), 164.314(a)(2)(iii)
isa-62443-2009 | 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 7.1, SR 7.2
iso27001-2013 | A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.17.2.1
nerc-cip | CIP-003-8 R5.2, CIP-004-6 R3.3
nist | CM-6(a), AU-4(1), AU-9(2)
nist-csf | PR.DS-4, PR.PT-1
os-srg | SRG-OS-000479-GPOS-00224, SRG-OS-000480-GPOS-00227, SRG-OS-000342-GPOS-00133
anssi | R71
cis | 5.1.1.6
ism | 0988, 1405
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    rsyslog_remote_loghost_address='logcollector'

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^\*\.\*")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s %s" "$stripped_key" "@@$rsyslog_remote_loghost_address"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^\*\.\*\\>" "/etc/rsyslog.conf"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^\*\.\*\\>.*/$escaped_formatted_output/gi" "/etc/rsyslog.conf"
    else
        if [[ -s "/etc/rsyslog.conf" ]] && [[ -n "$(tail -c 1 -- "/etc/rsyslog.conf" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "/etc/rsyslog.conf"
        fi
        printf '%s\n' "$formatted_output" >> "/etc/rsyslog.conf"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AU-4(1)
      - NIST-800-53-AU-9(2)
      - NIST-800-53-CM-6(a)
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - rsyslog_remote_loghost
    - name: XCCDF Value rsyslog_remote_loghost_address # promote to variable
      set_fact:
        rsyslog_remote_loghost_address: !!str logcollector
      tags:
        - always

    - name: Set rsyslog remote loghost
      ansible.builtin.lineinfile:
        dest: /etc/rsyslog.conf
        regexp: ^\*\.\*
        line: '*.* @@{{ rsyslog_remote_loghost_address }}'
        create: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AU-4(1)
      - NIST-800-53-AU-9(2)
      - NIST-800-53-CM-6(a)
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - rsyslog_remote_loghost
#### Rule Ensure rsyslog is Installed [ref]
Rsyslog is installed by default. The `rsyslog` package can be installed with the following command:
     $ sudo dnf install rsyslog
Rationale: | The rsyslog package provides the rsyslog daemon, which provides system logging services.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_package_rsyslog_installed
References: |
cis-csc | 1, 14, 15, 16, 3, 5, 6
cobit5 | APO11.04, BAI03.05, DSS05.04, DSS05.07, MEA02.01
hipaa | 164.312(a)(2)(ii)
isa-62443-2009 | 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9
iso27001-2013 | A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1
nist | CM-6(a)
nist-csf | PR.PT-1
os-srg | SRG-OS-000479-GPOS-00224, SRG-OS-000051-GPOS-00024, SRG-OS-000480-GPOS-00227
cis | 5.1.1.1
ism | 1409
Remediation OSBuild Blueprint snippet ⇲
    [[packages]]
    name = "rsyslog"
    version = "*"
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if ! rpm -q --quiet "rsyslog" ; then
        dnf install -y "rsyslog"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    package --add=rsyslog
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_rsyslog_installed

    - name: Ensure rsyslog is installed
      ansible.builtin.package:
        name: rsyslog
        state: present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_rsyslog_installed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include install_rsyslog

    class install_rsyslog {
      package { 'rsyslog':
        ensure => 'installed',
      }
    }
#### Rule Ensure rsyslog Default File Permissions Configured [ref]
rsyslog will create logfiles that do not already exist on the system. This settings controls what permissions will be applied to these newly created files.
Rationale: | It is important to ensure that log files have the correct permissions to ensure that sensitive data is archived and protected.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_rsyslog_filecreatemode
References: |
cis | 5.1.1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    sed -i '/^\s*$FileCreateMode/d' /etc/rsyslog.d/*

    if ! grep -qE '^\s*\$FileCreateMode\s+0640' /etc/rsyslog.conf; then
        if grep -qE '^\s*\$FileCreateMode' /etc/rsyslog.conf; then
            sed -i '/^\s*\$FileCreateMode/ s/^/#/' /etc/rsyslog.conf
        fi
        ## Assume there is no filter named as 00-, otherwise those filters might be included before this configuration and create file with different permissions
        echo '$FileCreateMode 0640' > /etc/rsyslog.d/00-rsyslog_filecreatemode.conf
    fi

    systemctl restart rsyslog.service

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_filecreatemode

    - name: Ensure rsyslog Default File Permissions Configured - Search for $FileCreateMode
        Parameter in rsyslog Main Config File
      ansible.builtin.find:
        paths: /etc
        pattern: rsyslog.conf
        contains: ^\s*\$FileCreateMode\s*\d+
      register: rsyslog_main_file_with_filecreatemode
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_filecreatemode

    - name: Ensure rsyslog Default File Permissions Configured - Search for $FileCreateMode
        Parameter in rsyslog Include Files
      ansible.builtin.find:
        paths: /etc/rsyslog.d/
        pattern: '*.conf'
        contains: ^\s*\$FileCreateMode\s*\d+
      register: rsyslog_includes_with_filecreatemode
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_filecreatemode

    - name: Ensure rsyslog Default File Permissions Configured - Assemble List of rsyslog
        Configuration Files with $FileCreateMode Parameter
      ansible.builtin.set_fact:
        rsyslog_filecreatemode_files: '{{ rsyslog_main_file_with_filecreatemode.files
          | map(attribute=''path'') | list + rsyslog_includes_with_filecreatemode.files
          | map(attribute=''path'') | list }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_filecreatemode

    - name: Ensure rsyslog Default File Permissions Configured - Remove $FileCreateMode
        Parameter from Multiple Files to Avoid Conflicts
      ansible.builtin.lineinfile:
        path: '{{ item }}'
        regexp: \$FileCreateMode.*
        state: absent
      register: result_rsyslog_filecreatemode_removed
      loop: '{{ rsyslog_filecreatemode_files }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - rsyslog_filecreatemode_files | length > 1
      tags:
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_filecreatemode

    - name: Ensure rsyslog Default File Permissions Configured - Add $FileCreateMode Parameter
        and Expected Value
      ansible.builtin.lineinfile:
        path: /etc/rsyslog.d/00-rsyslog_filecreatemode.conf
        line: $FileCreateMode 0640
        mode: 416
        create: true
      when:
      - '"kernel" in ansible_facts.packages'
      - rsyslog_filecreatemode_files | length == 0 or result_rsyslog_filecreatemode_removed
        is not skipped
      tags:
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_filecreatemode

    - name: Ensure rsyslog Default File Permissions Configured - Ensure Correct Value
        of Existing $FileCreateMode Parameter
      ansible.builtin.lineinfile:
        path: '{{ item }}'
        regexp: ^\$FileCreateMode
        line: $FileCreateMode 0640
      loop: '{{ rsyslog_filecreatemode_files }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - rsyslog_filecreatemode_files | length == 1
      tags:
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - rsyslog_filecreatemode
Group Network Configuration and Firewalls Group contains 10 groups and 35 rules
[ref] Most systems must be connected to a network of some sort, and this brings with it the substantial risk of network attack. This section discusses the security impact of decisions about networking which must be made when configuring a system. This section also discusses firewalls, network access controls, and other network security frameworks, which allow system-level rules to be written that can limit an attackers' ability to connect to your system. These rules can specify that network traffic should be allowed or denied from certain IP addresses, hosts, and networks. The rules can also specify which of the system's network services are available to particular hosts or networks.
Group firewalld Group contains 2 groups and 5 rules
[ref] The dynamic firewall daemon `firewalld` provides a dynamically managed firewall with support for network “zones” to assign a level of trust to a network and its associated connections and interfaces. It has support for IPv4 and IPv6 firewall settings. It supports Ethernet bridges and has a separation of runtime and permanent configuration options. It also has an interface for services or applications to add firewall rules directly. A graphical configuration tool, `firewall-config`, is used to configure `firewalld`, which in turn uses `iptables` tool to communicate with `Netfilter` in the kernel which implements packet filtering. The firewall service provided by `firewalld` is dynamic rather than static because changes to the configuration can be made at anytime and are immediately implemented. There is no need to save or apply the changes. No unintended disruption of existing network connections occurs as no part of the firewall has to be reloaded.
Group Inspect and Activate Default firewalld Rules Group contains 2 rules
[ref] Firewalls can be used to separate networks into different zones based on the level of trust the user has decided to place on the devices and traffic within that network. `NetworkManager` informs firewalld to which zone an interface belongs. An interface's assigned zone can be changed by `NetworkManager` or via the `firewall-config` tool. The zone settings in `/etc/firewalld/` are a range of preset settings which can be quickly applied to a network interface. These are the zones provided by firewalld sorted according to the default trust level of the zones from untrusted to trusted: `drop` Any incoming network packets are dropped, there is no reply. Only outgoing network connections are possible. `block` Any incoming network connections are rejected with an `icmp-host-prohibited` message for IPv4 and `icmp6-adm-prohibited` for IPv6. Only network connections initiated from within the system are possible. `public` For use in public areas. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted. `external` For use on external networks with masquerading enabled especially for routers. You do not trust the other computers on the network to not harm your computer. Only selected incoming connections are accepted. `dmz` For computers in your demilitarized zone that are publicly-accessible with limited access to your internal network. Only selected incoming connections are accepted. `work` For use in work areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted. `home` For use in home areas. You mostly trust the other computers on networks to not harm your computer. Only selected incoming connections are accepted. `internal` For use on internal networks. You mostly trust the other computers on the networks to not harm your computer. Only selected incoming connections are accepted. `trusted` All network connections are accepted. It is possible to designate one of these zones to be the default zone. When interface connections are added to `NetworkManager`, they are assigned to the default zone. On installation, the default zone in firewalld is set to be the public zone. To find out all the settings of a zone, for example the `public zone,` enter the following command as root:
    # firewall-cmd --zone=public --list-all
Example output of this command might look like the following:
    # firewall-cmd --zone=public --list-all
    public
      interfaces:
      services: mdns dhcpv6-client ssh
      ports:
      forward-ports:
      icmp-blocks: source-quench
To view the network zones currently active, enter the following command as root:
    # firewall-cmd --get-service
The following listing displays the result of this command on common Amazon Linux 2023 system:
    # firewall-cmd --get-service
    amanda-client bacula bacula-client dhcp dhcpv6 dhcpv6-client dns ftp
    high-availability http https imaps ipp ipp-client ipsec kerberos kpasswd
    ldap ldaps libvirt libvirt-tls mdns mountd ms-wbt mysql nfs ntp openvpn
    pmcd pmproxy pmwebapi pmwebapis pop3s postgresql proxy-dhcp radius rpc-bind
    samba samba-client smtp ssh telnet tftp tftp-client transmission-client
    vnc-server wbem-https
Finally to view the network zones that will be active after the next firewalld service reload, enter the following command as root:
    # firewall-cmd --get-service --permanent
#### Rule Install firewalld Package [ref]
The `firewalld` package can be installed with the following command:
    $ sudo dnf install firewalld
Rationale: | "Firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to nonpublic information systems by an authorized user (or an information system) communicating through an external, non-organization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Amazon Linux 2023 functionality (e.g., SSH) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets)."
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_package_firewalld_installed
References: |
nist | CM-6(a)
ospp | FMT_SMF_EXT.1
os-srg | SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115, SRG-OS-000298-GPOS-00116, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00232
cis | 3.4.1.2
ism | 1409
pcidss4 | 1.2.1, 1.2
Remediation OSBuild Blueprint snippet ⇲
    [[packages]]
    name = "firewalld"
    version = "*"
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if ! rpm -q --quiet "firewalld" ; then
        dnf install -y "firewalld"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    package --add=firewalld
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.1
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_firewalld_installed

    - name: Ensure firewalld is installed
      ansible.builtin.package:
        name: firewalld
        state: present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.1
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_firewalld_installed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include install_firewalld

    class install_firewalld {
      package { 'firewalld':
        ensure => 'installed',
      }
    }
#### Rule Verify firewalld Enabled [ref]
The `firewalld` service can be enabled with the following command:
    $ sudo systemctl enable firewalld.service
Rationale: | Access control methods provide the ability to enhance system security posture by restricting services and known good IP addresses and address ranges. This prevents connections from unknown hosts and protocols.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_service_firewalld_enabled
References: |
cis-csc | 11, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05
cui | 3.1.3, 3.4.7
isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4
nerc-cip | CIP-003-8 R4, CIP-003-8 R5, CIP-004-6 R3
nist | AC-4, CM-7(b), CA-3(5), SC-7(21), CM-6(a)
nist-csf | PR.IP-1
ospp | FMT_SMF_EXT.1
os-srg | SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115, SRG-OS-000480-GPOS-00227, SRG-OS-000480-GPOS-00231, SRG-OS-000480-GPOS-00232
bsi | SYS.1.6.A5, SYS.1.6.A21
cis | 3.4.1.2
ism | 1409
pcidss4 | 1.2.1, 1.2
Remediation OSBuild Blueprint snippet ⇲
    [customizations.services]
    enabled = ["firewalld"]
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q firewalld; }; then

    SYSTEMCTL_EXEC='/usr/bin/systemctl'
    "$SYSTEMCTL_EXEC" unmask 'firewalld.service'
    if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
      "$SYSTEMCTL_EXEC" start 'firewalld.service'
    fi
    "$SYSTEMCTL_EXEC" enable 'firewalld.service'

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.3
      - NIST-800-171-3.4.7
      - NIST-800-53-AC-4
      - NIST-800-53-CA-3(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(21)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.1
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_firewalld_enabled

    - name: Verify firewalld Enabled - Enable service firewalld
      block:

      - name: Gather the package facts
        ansible.builtin.package_facts:
          manager: auto

      - name: Verify firewalld Enabled - Enable Service firewalld
        ansible.builtin.systemd:
          name: firewalld
          enabled: true
          state: started
          masked: false
        when:
        - '"firewalld" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.3
      - NIST-800-171-3.4.7
      - NIST-800-53-AC-4
      - NIST-800-53-CA-3(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(21)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.1
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_firewalld_enabled
      - special_service_block
      when:
      - '"kernel" in ansible_facts.packages'
      - '"firewalld" in ansible_facts.packages'
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include enable_firewalld

    class enable_firewalld {
      service {'firewalld':
        enable => true,
        ensure => 'running',
      }
    }
Group Strengthen the Default Ruleset Group contains 3 rules
[ref] The default rules can be strengthened. The system scripts that activate the firewall rules expect them to be defined in configuration files under the `/etc/firewalld/services` and `/etc/firewalld/zones` directories. The following recommendations describe how to strengthen the default ruleset configuration file. An alternative to editing this configuration file is to create a shell script that makes calls to the `firewall-cmd` program to load in rules under the `/etc/firewalld/services` and `/etc/firewalld/zones` directories. Instructions apply to both unless otherwise noted. Language and address conventions for regular firewalld rules are used throughout this section. Warning: The program `firewall-config` allows additional services to penetrate the default firewall rules and automatically adjusts the `firewalld` ruleset(s).
#### Rule Configure Firewalld to Restrict Loopback Traffic [ref]
Configure `firewalld` to restrict loopback traffic to the `lo` interface. The loopback traffic must be trusted by assigning the `lo` interface to the `firewalld` `trusted` zone. However, the loopback traffic must be restricted to the loopback interface as an anti-spoofing measure. To configure `firewalld` to restrict loopback traffic to the `lo` interface, run the following commands:
    sudo firewall-cmd --permanent --zone=trusted --add-rich-rule='rule family=ipv4 source address="127.0.0.1" destination not address="127.0.0.1" drop'
    sudo firewall-cmd --permanent --zone=trusted --add-rich-rule='rule family=ipv6 source address="::1" destination not address="::1" drop'
To ensure `firewalld` settings are applied in runtime, run the following command:
    firewall-cmd --reload
Rationale: | Loopback traffic is generated between processes on machine and is typically critical to operation of the system. The loopback interface is the only place that loopback network traffic should be seen, all other interfaces should ignore traffic on this network as an anti-spoofing measure.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_firewalld_loopback_traffic_restricted
References: |
cis | 3.4.2.4
pcidss4 | 1.4.1, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if ! rpm -q --quiet "firewalld" ; then
        dnf install -y "firewalld"
    fi

    ipv4_rule='rule family=ipv4 source address="127.0.0.1" destination not address="127.0.0.1" drop'
    ipv6_rule='rule family=ipv6 source address="::1" destination not address="::1" drop'

    if test "$(stat -c %d:%i /)" != "$(stat -c %d:%i /proc/1/root/.)" || { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; }; then
        firewall-offline-cmd --zone=trusted --add-rich-rule="${ipv4_rule}"
        firewall-offline-cmd --zone=trusted --add-rich-rule="${ipv6_rule}"
    elif systemctl is-active firewalld; then
        firewall-cmd --permanent --zone=trusted --add-rich-rule="${ipv4_rule}"
        firewall-cmd --permanent --zone=trusted --add-rich-rule="${ipv6_rule}"
        firewall-cmd --reload
    else
        echo "
        firewalld service is not active. Remediation aborted!
        This remediation could not be applied because it depends on firewalld service running.
        The service is not started by this remediation in order to prevent connection issues."
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.1
      - configure_strategy
      - firewalld_loopback_traffic_restricted
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure Firewalld to Restrict Loopback Traffic - Ensure firewalld Package
        is Installed
      ansible.builtin.package:
        name: '{{ item }}'
        state: present
      with_items:
      - firewalld
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.1
      - configure_strategy
      - firewalld_loopback_traffic_restricted
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure Firewalld to Restrict Loopback Traffic - Collect Facts About System
        Services
      ansible.builtin.service_facts: null
      register: result_services_states
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.1
      - configure_strategy
      - firewalld_loopback_traffic_restricted
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure Firewalld to Restrict Loopback Traffic - Remediation is Applicable
        if firewalld Service is Running
      block:

      - name: Configure Firewalld to Restrict Loopback Traffic - Ensure firewalld trusted
          Zone Restricts IPv4 Loopback Traffic
        ansible.builtin.command:
          cmd: firewall-cmd --permanent --zone=trusted --add-rich-rule='rule family=ipv4
            source address="127.0.0.1" destination not address="127.0.0.1" drop'
        register: result_trusted_ipv4_restriction
        changed_when:
        - '''ALREADY_ENABLED'' not in result_trusted_ipv4_restriction.stderr'

      - name: Configure Firewalld to Restrict Loopback Traffic - Ensure firewalld trusted
          Zone Restricts IPv6 Loopback Traffic
        ansible.builtin.command:
          cmd: firewall-cmd --permanent --zone=trusted --add-rich-rule='rule family=ipv6
            source address="::1" destination not address="::1" drop'
        register: result_trusted_ipv6_restriction
        changed_when:
        - '''ALREADY_ENABLED'' not in result_trusted_ipv6_restriction.stderr'

      - name: Configure Firewalld to Restrict Loopback Traffic - Ensure firewalld Changes
          are Applied
        ansible.builtin.service:
          name: firewalld
          state: reloaded
        when:
        - result_trusted_ipv4_restriction is changed or result_trusted_ipv6_restriction
          is changed
      when:
      - '"kernel" in ansible_facts.packages'
      - ansible_facts.services['firewalld.service'].state == 'running'
      tags:
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.1
      - configure_strategy
      - firewalld_loopback_traffic_restricted
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure Firewalld to Restrict Loopback Traffic - Informative Message Based
        on Service State
      ansible.builtin.assert:
        that:
        - ansible_check_mode or ansible_facts.services['firewalld.service'].state == 'running'
        fail_msg:
        - firewalld service is not active. Remediation aborted!
        - This remediation could not be applied because it depends on firewalld service
          running.
        - The service is not started by this remediation in order to prevent connection
          issues.
        success_msg:
        - Configure Firewalld to Restrict Loopback Traffic remediation successfully executed
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.1
      - configure_strategy
      - firewalld_loopback_traffic_restricted
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Configure Firewalld to Trust Loopback Traffic [ref]
Assign loopback interface to the `firewalld` `trusted` zone in order to explicitly allow the loopback traffic in the system. To configure `firewalld` to trust loopback traffic, run the following command:
    sudo firewall-cmd --permanent --zone=trusted --add-interface=lo
To ensure `firewalld` settings are applied in runtime, run the following command:
    firewall-cmd --reload
Rationale: | Loopback traffic is generated between processes on machine and is typically critical to operation of the system. The loopback interface is the only place that loopback network traffic should be seen, all other interfaces should ignore traffic on this network as an anti-spoofing measure.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_firewalld_loopback_traffic_trusted
References: |
cis | 3.4.2.4
pcidss4 | 1.4.1, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if ! rpm -q --quiet "firewalld" ; then
        dnf install -y "firewalld"
    fi

    if test "$(stat -c %d:%i /)" != "$(stat -c %d:%i /proc/1/root/.)" || { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; }; then
        firewall-offline-cmd --zone=trusted --add-interface=lo
    elif systemctl is-active firewalld; then
        firewall-cmd --permanent --zone=trusted --add-interface=lo
        firewall-cmd --reload
    else
        echo "
        firewalld service is not active. Remediation aborted!
        This remediation could not be applied because it depends on firewalld service running.
        The service is not started by this remediation in order to prevent connection issues."
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.1
      - configure_strategy
      - firewalld_loopback_traffic_trusted
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure Firewalld to Trust Loopback Traffic - Ensure firewalld Package is
        Installed
      ansible.builtin.package:
        name: '{{ item }}'
        state: present
      with_items:
      - firewalld
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.1
      - configure_strategy
      - firewalld_loopback_traffic_trusted
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure Firewalld to Trust Loopback Traffic - Collect Facts About System
        Services
      ansible.builtin.service_facts: null
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.1
      - configure_strategy
      - firewalld_loopback_traffic_trusted
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure Firewalld to Trust Loopback Traffic - Remediation is Applicable
        if firewalld Service is Running
      block:

      - name: Configure Firewalld to Trust Loopback Traffic - Ensure firewalld trusted
          Zone Includes lo Interface
        ansible.builtin.command:
          cmd: firewall-cmd --permanent --zone=trusted --add-interface=lo
        register: result_lo_interface_assignment
        changed_when:
        - '''ALREADY_ENABLED'' not in result_lo_interface_assignment.stderr'

      - name: Configure Firewalld to Trust Loopback Traffic - Ensure firewalld Changes
          are Applied
        ansible.builtin.service:
          name: firewalld
          state: reloaded
        when:
        - result_lo_interface_assignment is changed
      when:
      - '"kernel" in ansible_facts.packages'
      - ansible_facts.services['firewalld.service'].state == 'running'
      tags:
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.1
      - configure_strategy
      - firewalld_loopback_traffic_trusted
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Configure Firewalld to Trust Loopback Traffic - Informative Message Based
        on Service State
      ansible.builtin.assert:
        that:
        - ansible_check_mode or ansible_facts.services['firewalld.service'].state == 'running'
        fail_msg:
        - firewalld service is not active. Remediation aborted!
        - This remediation could not be applied because it depends on firewalld service
          running.
        - The service is not started by this remediation in order to prevent connection
          issues.
        success_msg:
        - Configure Firewalld to Trust Loopback Traffic remediation successfully executed
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.1
      - configure_strategy
      - firewalld_loopback_traffic_trusted
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Set Default firewalld Zone for Incoming Packets [ref]
To set the default zone to `drop` for the built-in default zone which processes incoming IPv4 and IPv6 packets, modify the following line in `/etc/firewalld/firewalld.conf` to be:
    DefaultZone=drop
Warning: To prevent denying any access to the system, automatic remediation of this control is not available. Remediation must be automated as a component of machine provisioning, or followed manually as outlined above.
Rationale: | In `firewalld` the default zone is applied only after all the applicable rules in the table are examined for a match. Setting the default zone to `drop` implements proper design for a firewall, i.e. any packets which are not explicitly permitted should not be accepted.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_set_firewalld_default_zone
References: |
cis-csc | 11, 14, 3, 9
cjis | 5.10.1
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.1.3, 3.4.7, 3.13.6
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CA-3(5), CM-7(b), SC-7(23), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
pcidss | Req-1.4
os-srg | SRG-OS-000480-GPOS-00227
cis | 3.4.2.1
ism | 1416
pcidss4 | 1.3.1, 1.3
Group IPv6 Group contains 1 group and 7 rules
[ref] The system includes support for Internet Protocol version 6. A major and often-mentioned improvement over IPv4 is its enormous increase in the number of available addresses. Another important feature is its support for automatic configuration of many network settings.
Group Configure IPv6 Settings if Necessary Group contains 7 rules
[ref] A major feature of IPv6 is the extent to which systems implementing it can automatically configure their networking devices using information from the network. From a security perspective, manually configuring important configuration information is preferable to accepting it from the network in an unauthenticated fashion.
#### Rule Configure Accepting Router Advertisements on All IPv6 Interfaces [ref]
To set the runtime status of the `net.ipv6.conf.all.accept_ra` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.all.accept_ra=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.all.accept_ra = 0
Rationale: | An illicit router advertisement message could result in a man-in-the-middle attack.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_ra
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
os-srg | SRG-OS-000480-GPOS-00227
cis | 3.3.9
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv6.conf.all.accept_ra from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_ra.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv6.conf.all.accept_ra" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv6_conf_all_accept_ra_value='0'

    #
    # Set runtime for net.ipv6.conf.all.accept_ra
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv6.conf.all.accept_ra="$sysctl_net_ipv6_conf_all_accept_ra_value"
    fi

    #
    # If net.ipv6.conf.all.accept_ra present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv6.conf.all.accept_ra = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_ra")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_ra_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_ra\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_ra\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_ra
    - name: XCCDF Value sysctl_net_ipv6_conf_all_accept_ra_value # promote to variable
      set_fact:
        sysctl_net_ipv6_conf_all_accept_ra_value: !!str 0
      tags:
        - always

    - name: Configure Accepting Router Advertisements on All IPv6 Interfaces - Set fact
        for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_ra

    - name: Configure Accepting Router Advertisements on All IPv6 Interfaces - Find all
        files that contain net.ipv6.conf.all.accept_ra
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.all.accept_ra\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_ra

    - name: Configure Accepting Router Advertisements on All IPv6 Interfaces - Find all
        files that set net.ipv6.conf.all.accept_ra to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.all.accept_ra\s*=\s*{{ sysctl_net_ipv6_conf_all_accept_ra_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_ra

    - name: Configure Accepting Router Advertisements on All IPv6 Interfaces - Comment
        out any occurrences of net.ipv6.conf.all.accept_ra from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv6.conf.all.accept_ra
        replace: '#net.ipv6.conf.all.accept_ra'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_ra

    - name: Configure Accepting Router Advertisements on All IPv6 Interfaces - Ensure
        sysctl net.ipv6.conf.all.accept_ra is set
      ansible.posix.sysctl:
        name: net.ipv6.conf.all.accept_ra
        value: '{{ sysctl_net_ipv6_conf_all_accept_ra_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_ra
#### Rule Disable Accepting ICMP Redirects for All IPv6 Interfaces [ref]
To set the runtime status of the `net.ipv6.conf.all.accept_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.all.accept_redirects = 0
Rationale: | An illicit ICMP redirect message could result in a man-in-the-middle attack.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_redirects
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv)
nist-csf | PR.IP-1, PR.PT-3
os-srg | SRG-OS-000480-GPOS-00227
anssi | R13
cis | 3.3.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv6.conf.all.accept_redirects from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_redirects.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv6.conf.all.accept_redirects" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv6_conf_all_accept_redirects_value='0'

    #
    # Set runtime for net.ipv6.conf.all.accept_redirects
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv6.conf.all.accept_redirects="$sysctl_net_ipv6_conf_all_accept_redirects_value"
    fi

    #
    # If net.ipv6.conf.all.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv6.conf.all.accept_redirects = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_redirects")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_redirects_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_redirects
    - name: XCCDF Value sysctl_net_ipv6_conf_all_accept_redirects_value # promote to variable
      set_fact:
        sysctl_net_ipv6_conf_all_accept_redirects_value: !!str 0
      tags:
        - always

    - name: Disable Accepting ICMP Redirects for All IPv6 Interfaces - Set fact for sysctl
        paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_redirects

    - name: Disable Accepting ICMP Redirects for All IPv6 Interfaces - Find all files
        that contain net.ipv6.conf.all.accept_redirects
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.all.accept_redirects\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_redirects

    - name: Disable Accepting ICMP Redirects for All IPv6 Interfaces - Find all files
        that set net.ipv6.conf.all.accept_redirects to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.all.accept_redirects\s*=\s*{{ sysctl_net_ipv6_conf_all_accept_redirects_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_redirects

    - name: Disable Accepting ICMP Redirects for All IPv6 Interfaces - Comment out any
        occurrences of net.ipv6.conf.all.accept_redirects from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv6.conf.all.accept_redirects
        replace: '#net.ipv6.conf.all.accept_redirects'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_redirects

    - name: Disable Accepting ICMP Redirects for All IPv6 Interfaces - Ensure sysctl net.ipv6.conf.all.accept_redirects
        is set
      ansible.posix.sysctl:
        name: net.ipv6.conf.all.accept_redirects
        value: '{{ sysctl_net_ipv6_conf_all_accept_redirects_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_redirects
#### Rule Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces [ref]
To set the runtime status of the `net.ipv6.conf.all.accept_source_route` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.all.accept_source_route = 0
Rationale: | Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_accept_source_route
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9
cobit5 | APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.4.3.3
isa-62443-2013 | SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R13
cis | 3.3.1
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv6.conf.all.accept_source_route from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.accept_source_route.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv6.conf.all.accept_source_route" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv6_conf_all_accept_source_route_value='0'

    #
    # Set runtime for net.ipv6.conf.all.accept_source_route
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv6.conf.all.accept_source_route="$sysctl_net_ipv6_conf_all_accept_source_route_value"
    fi

    #
    # If net.ipv6.conf.all.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv6.conf.all.accept_source_route = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.accept_source_route")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_accept_source_route_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_source_route
    - name: XCCDF Value sysctl_net_ipv6_conf_all_accept_source_route_value # promote to variable
      set_fact:
        sysctl_net_ipv6_conf_all_accept_source_route_value: !!str 0
      tags:
        - always

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
        - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
        - Find all files that contain net.ipv6.conf.all.accept_source_route
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.all.accept_source_route\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
        - Find all files that set net.ipv6.conf.all.accept_source_route to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.all.accept_source_route\s*=\s*{{ sysctl_net_ipv6_conf_all_accept_source_route_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
        - Comment out any occurrences of net.ipv6.conf.all.accept_source_route from config
        files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv6.conf.all.accept_source_route
        replace: '#net.ipv6.conf.all.accept_source_route'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv6 Interfaces
        - Ensure sysctl net.ipv6.conf.all.accept_source_route is set
      ansible.posix.sysctl:
        name: net.ipv6.conf.all.accept_source_route
        value: '{{ sysctl_net_ipv6_conf_all_accept_source_route_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_accept_source_route
#### Rule Disable Kernel Parameter for IPv6 Forwarding [ref]
To set the runtime status of the `net.ipv6.conf.all.forwarding` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.all.forwarding=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.all.forwarding = 0
Rationale: | IP forwarding permits the kernel to forward packets from one network interface to another. The ability to forward packets between two networks is only appropriate for systems acting as routers.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_all_forwarding
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9
cobit5 | APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv)
nist-csf | DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3
os-srg | SRG-OS-000480-GPOS-00227
cis | 3.2.1
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv6.conf.all.forwarding from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.all.forwarding.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv6.conf.all.forwarding" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv6_conf_all_forwarding_value='0'

    #
    # Set runtime for net.ipv6.conf.all.forwarding
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv6.conf.all.forwarding="$sysctl_net_ipv6_conf_all_forwarding_value"
    fi

    #
    # If net.ipv6.conf.all.forwarding present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv6.conf.all.forwarding = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.all.forwarding")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_all_forwarding_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.all.forwarding\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.all.forwarding\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_forwarding
    - name: XCCDF Value sysctl_net_ipv6_conf_all_forwarding_value # promote to variable
      set_fact:
        sysctl_net_ipv6_conf_all_forwarding_value: !!str 0
      tags:
        - always

    - name: Disable Kernel Parameter for IPv6 Forwarding - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_forwarding

    - name: Disable Kernel Parameter for IPv6 Forwarding - Find all files that contain
        net.ipv6.conf.all.forwarding
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.all.forwarding\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_forwarding

    - name: Disable Kernel Parameter for IPv6 Forwarding - Find all files that set net.ipv6.conf.all.forwarding
        to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.all.forwarding\s*=\s*{{ sysctl_net_ipv6_conf_all_forwarding_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_forwarding

    - name: Disable Kernel Parameter for IPv6 Forwarding - Comment out any occurrences
        of net.ipv6.conf.all.forwarding from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv6.conf.all.forwarding
        replace: '#net.ipv6.conf.all.forwarding'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_forwarding

    - name: Disable Kernel Parameter for IPv6 Forwarding - Ensure sysctl net.ipv6.conf.all.forwarding
        is set
      ansible.posix.sysctl:
        name: net.ipv6.conf.all.forwarding
        value: '{{ sysctl_net_ipv6_conf_all_forwarding_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_all_forwarding
#### Rule Disable Accepting Router Advertisements on all IPv6 Interfaces by Default [ref]
To set the runtime status of the `net.ipv6.conf.default.accept_ra` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.default.accept_ra=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.default.accept_ra = 0
Rationale: | An illicit router advertisement message could result in a man-in-the-middle attack.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_ra
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
os-srg | SRG-OS-000480-GPOS-00227
cis | 3.3.9
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv6.conf.default.accept_ra from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_ra.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv6.conf.default.accept_ra" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv6_conf_default_accept_ra_value='0'

    #
    # Set runtime for net.ipv6.conf.default.accept_ra
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv6.conf.default.accept_ra="$sysctl_net_ipv6_conf_default_accept_ra_value"
    fi

    #
    # If net.ipv6.conf.default.accept_ra present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv6.conf.default.accept_ra = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_ra")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_ra_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_ra\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_ra\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_ra
    - name: XCCDF Value sysctl_net_ipv6_conf_default_accept_ra_value # promote to variable
      set_fact:
        sysctl_net_ipv6_conf_default_accept_ra_value: !!str 0
      tags:
        - always

    - name: Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
        - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_ra

    - name: Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
        - Find all files that contain net.ipv6.conf.default.accept_ra
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.default.accept_ra\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_ra

    - name: Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
        - Find all files that set net.ipv6.conf.default.accept_ra to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.default.accept_ra\s*=\s*{{ sysctl_net_ipv6_conf_default_accept_ra_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_ra

    - name: Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
        - Comment out any occurrences of net.ipv6.conf.default.accept_ra from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv6.conf.default.accept_ra
        replace: '#net.ipv6.conf.default.accept_ra'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_ra

    - name: Disable Accepting Router Advertisements on all IPv6 Interfaces by Default
        - Ensure sysctl net.ipv6.conf.default.accept_ra is set
      ansible.posix.sysctl:
        name: net.ipv6.conf.default.accept_ra
        value: '{{ sysctl_net_ipv6_conf_default_accept_ra_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_ra
#### Rule Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces [ref]
To set the runtime status of the `net.ipv6.conf.default.accept_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.default.accept_redirects = 0
Rationale: | An illicit ICMP redirect message could result in a man-in-the-middle attack.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_redirects
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
os-srg | SRG-OS-000480-GPOS-00227
anssi | R13
cis | 3.3.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv6.conf.default.accept_redirects from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_redirects.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv6.conf.default.accept_redirects" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv6_conf_default_accept_redirects_value='0'

    #
    # Set runtime for net.ipv6.conf.default.accept_redirects
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv6.conf.default.accept_redirects="$sysctl_net_ipv6_conf_default_accept_redirects_value"
    fi

    #
    # If net.ipv6.conf.default.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv6.conf.default.accept_redirects = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_redirects")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_redirects_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_redirects
    - name: XCCDF Value sysctl_net_ipv6_conf_default_accept_redirects_value # promote to variable
      set_fact:
        sysctl_net_ipv6_conf_default_accept_redirects_value: !!str 0
      tags:
        - always

    - name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
        - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_redirects

    - name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
        - Find all files that contain net.ipv6.conf.default.accept_redirects
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.default.accept_redirects\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_redirects

    - name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
        - Find all files that set net.ipv6.conf.default.accept_redirects to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.default.accept_redirects\s*=\s*{{ sysctl_net_ipv6_conf_default_accept_redirects_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_redirects

    - name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
        - Comment out any occurrences of net.ipv6.conf.default.accept_redirects from config
        files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv6.conf.default.accept_redirects
        replace: '#net.ipv6.conf.default.accept_redirects'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_redirects

    - name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv6 Interfaces
        - Ensure sysctl net.ipv6.conf.default.accept_redirects is set
      ansible.posix.sysctl:
        name: net.ipv6.conf.default.accept_redirects
        value: '{{ sysctl_net_ipv6_conf_default_accept_redirects_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_redirects
#### Rule Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces by Default [ref]
To set the runtime status of the `net.ipv6.conf.default.accept_source_route` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv6.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv6.conf.default.accept_source_route = 0
Rationale: | Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv6 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv6_conf_default_accept_source_route
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 18, 4, 6, 8, 9
cobit5 | APO01.06, APO13.01, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.07, DSS06.02
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.4.3.3
isa-62443-2013 | SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-7(a), CM-7(b), CM-6(a), CM-6(b), CM-6.1(iv)
nist-csf | DE.AE-1, ID.AM-3, PR.AC-5, PR.DS-5, PR.PT-4
pcidss | Req-1.4.3
os-srg | SRG-OS-000480-GPOS-00227
anssi | R13
cis | 3.3.1
pcidss4 | 1.4.2, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv6.conf.default.accept_source_route from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv6.conf.default.accept_source_route.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv6.conf.default.accept_source_route" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv6_conf_default_accept_source_route_value='0'

    #
    # Set runtime for net.ipv6.conf.default.accept_source_route
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv6.conf.default.accept_source_route="$sysctl_net_ipv6_conf_default_accept_source_route_value"
    fi

    #
    # If net.ipv6.conf.default.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv6.conf.default.accept_source_route = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv6.conf.default.accept_source_route")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv6_conf_default_accept_source_route_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv6.conf.default.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv6.conf.default.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_source_route
    - name: XCCDF Value sysctl_net_ipv6_conf_default_accept_source_route_value # promote to variable
      set_fact:
        sysctl_net_ipv6_conf_default_accept_source_route_value: !!str 0
      tags:
        - always

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces
        by Default - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces
        by Default - Find all files that contain net.ipv6.conf.default.accept_source_route
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.default.accept_source_route\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces
        by Default - Find all files that set net.ipv6.conf.default.accept_source_route
        to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv6.conf.default.accept_source_route\s*=\s*{{ sysctl_net_ipv6_conf_default_accept_source_route_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces
        by Default - Comment out any occurrences of net.ipv6.conf.default.accept_source_route
        from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv6.conf.default.accept_source_route
        replace: '#net.ipv6.conf.default.accept_source_route'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv6 Interfaces
        by Default - Ensure sysctl net.ipv6.conf.default.accept_source_route is set
      ansible.posix.sysctl:
        name: net.ipv6.conf.default.accept_source_route
        value: '{{ sysctl_net_ipv6_conf_default_accept_source_route_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(b)
      - NIST-800-53-CM-6.1(iv)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv6_conf_default_accept_source_route
Group Kernel Parameters Which Affect Networking Group contains 2 groups and 16 rules
[ref] The `sysctl` utility is used to set parameters which affect the operation of the Linux kernel. Kernel parameters which affect networking and have security implications are described here.
Group Network Related Kernel Runtime Parameters for Hosts and Routers Group contains 13 rules
[ref] Certain kernel parameters should be set for systems which are acting as either hosts or routers to improve the system's ability defend against certain types of IPv4 protocol attacks.
#### Rule Disable Accepting ICMP Redirects for All IPv4 Interfaces [ref]
To set the runtime status of the `net.ipv4.conf.all.accept_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.all.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.all.accept_redirects = 0
Rationale: | ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required."
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_accept_redirects
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9
cjis | 5.10.1.1
cobit5 | APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a), SC-7(a)
nist-csf | DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3
os-srg | SRG-OS-000480-GPOS-00227
anssi | R12
cis | 3.3.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.conf.all.accept_redirects from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.accept_redirects.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.conf.all.accept_redirects" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_conf_all_accept_redirects_value='0'

    #
    # Set runtime for net.ipv4.conf.all.accept_redirects
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.conf.all.accept_redirects="$sysctl_net_ipv4_conf_all_accept_redirects_value"
    fi

    #
    # If net.ipv4.conf.all.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.conf.all.accept_redirects = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.accept_redirects")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_accept_redirects_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_accept_redirects
    - name: XCCDF Value sysctl_net_ipv4_conf_all_accept_redirects_value # promote to variable
      set_fact:
        sysctl_net_ipv4_conf_all_accept_redirects_value: !!str 0
      tags:
        - always

    - name: Disable Accepting ICMP Redirects for All IPv4 Interfaces - Set fact for sysctl
        paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_accept_redirects

    - name: Disable Accepting ICMP Redirects for All IPv4 Interfaces - Find all files
        that contain net.ipv4.conf.all.accept_redirects
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.all.accept_redirects\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_accept_redirects

    - name: Disable Accepting ICMP Redirects for All IPv4 Interfaces - Find all files
        that set net.ipv4.conf.all.accept_redirects to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.all.accept_redirects\s*=\s*{{ sysctl_net_ipv4_conf_all_accept_redirects_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_accept_redirects

    - name: Disable Accepting ICMP Redirects for All IPv4 Interfaces - Comment out any
        occurrences of net.ipv4.conf.all.accept_redirects from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.conf.all.accept_redirects
        replace: '#net.ipv4.conf.all.accept_redirects'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_accept_redirects

    - name: Disable Accepting ICMP Redirects for All IPv4 Interfaces - Ensure sysctl net.ipv4.conf.all.accept_redirects
        is set
      ansible.posix.sysctl:
        name: net.ipv4.conf.all.accept_redirects
        value: '{{ sysctl_net_ipv4_conf_all_accept_redirects_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_accept_redirects
#### Rule Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces [ref]
To set the runtime status of the `net.ipv4.conf.all.accept_source_route` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.all.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.all.accept_source_route = 0
Rationale: | Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routerd traffic, such as when IPv4 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_accept_source_route
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cobit5 | APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nist | CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a)
nist-csf | DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R12
cis | 3.3.1
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.conf.all.accept_source_route from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.accept_source_route.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.conf.all.accept_source_route" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_conf_all_accept_source_route_value='0'

    #
    # Set runtime for net.ipv4.conf.all.accept_source_route
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.conf.all.accept_source_route="$sysctl_net_ipv4_conf_all_accept_source_route_value"
    fi

    #
    # If net.ipv4.conf.all.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.conf.all.accept_source_route = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.accept_source_route")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_accept_source_route_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_accept_source_route
    - name: XCCDF Value sysctl_net_ipv4_conf_all_accept_source_route_value # promote to variable
      set_fact:
        sysctl_net_ipv4_conf_all_accept_source_route_value: !!str 0
      tags:
        - always

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
        - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
        - Find all files that contain net.ipv4.conf.all.accept_source_route
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.all.accept_source_route\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
        - Find all files that set net.ipv4.conf.all.accept_source_route to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.all.accept_source_route\s*=\s*{{ sysctl_net_ipv4_conf_all_accept_source_route_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
        - Comment out any occurrences of net.ipv4.conf.all.accept_source_route from config
        files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.conf.all.accept_source_route
        replace: '#net.ipv4.conf.all.accept_source_route'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on all IPv4 Interfaces
        - Ensure sysctl net.ipv4.conf.all.accept_source_route is set
      ansible.posix.sysctl:
        name: net.ipv4.conf.all.accept_source_route
        value: '{{ sysctl_net_ipv4_conf_all_accept_source_route_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_accept_source_route
#### Rule Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces [ref]
To set the runtime status of the `net.ipv4.conf.all.log_martians` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.all.log_martians=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.all.log_martians = 1
Rationale: | The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_log_martians
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9
cobit5 | APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.04, DSS03.05, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.11.2.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.2.1, A.6.2.2, A.9.1.2
nist | CM-7(a), CM-7(b), SC-5(3)(a)
nist-csf | DE.CM-1, PR.AC-3, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
cis | 3.3.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.conf.all.log_martians from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.log_martians.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.conf.all.log_martians" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_conf_all_log_martians_value='1'

    #
    # Set runtime for net.ipv4.conf.all.log_martians
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.conf.all.log_martians="$sysctl_net_ipv4_conf_all_log_martians_value"
    fi

    #
    # If net.ipv4.conf.all.log_martians present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.conf.all.log_martians = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.log_martians")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_log_martians_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.log_martians\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.log_martians\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(3)(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_conf_all_log_martians
      - unknown_severity
    - name: XCCDF Value sysctl_net_ipv4_conf_all_log_martians_value # promote to variable
      set_fact:
        sysctl_net_ipv4_conf_all_log_martians_value: !!str 1
      tags:
        - always

    - name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces - Set
        fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(3)(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_conf_all_log_martians
      - unknown_severity

    - name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces - Find
        all files that contain net.ipv4.conf.all.log_martians
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.all.log_martians\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(3)(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_conf_all_log_martians
      - unknown_severity

    - name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces - Find
        all files that set net.ipv4.conf.all.log_martians to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.all.log_martians\s*=\s*{{ sysctl_net_ipv4_conf_all_log_martians_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(3)(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_conf_all_log_martians
      - unknown_severity

    - name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces - Comment
        out any occurrences of net.ipv4.conf.all.log_martians from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.conf.all.log_martians
        replace: '#net.ipv4.conf.all.log_martians'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(3)(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_conf_all_log_martians
      - unknown_severity

    - name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces - Ensure
        sysctl net.ipv4.conf.all.log_martians is set
      ansible.posix.sysctl:
        name: net.ipv4.conf.all.log_martians
        value: '{{ sysctl_net_ipv4_conf_all_log_martians_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(3)(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_conf_all_log_martians
      - unknown_severity
#### Rule Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces [ref]
To set the runtime status of the `net.ipv4.conf.all.rp_filter` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.all.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.all.rp_filter = 1
Rationale: | Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_rp_filter
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9
cobit5 | APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.4.3.3
isa-62443-2013 | SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-7(a), CM-7(b), CM-6(a), SC-7(a)
nist-csf | DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4
pcidss | Req-1.4.3
os-srg | SRG-OS-000480-GPOS-00227
anssi | R12
cis | 3.3.7
pcidss4 | 1.4.3, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.conf.all.rp_filter from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.rp_filter.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.conf.all.rp_filter" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_conf_all_rp_filter_value='1'

    #
    # Set runtime for net.ipv4.conf.all.rp_filter
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.conf.all.rp_filter="$sysctl_net_ipv4_conf_all_rp_filter_value"
    fi

    #
    # If net.ipv4.conf.all.rp_filter present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.conf.all.rp_filter = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.rp_filter")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_rp_filter_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.rp_filter\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.rp_filter\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_rp_filter
    - name: XCCDF Value sysctl_net_ipv4_conf_all_rp_filter_value # promote to variable
      set_fact:
        sysctl_net_ipv4_conf_all_rp_filter_value: !!str 1
      tags:
        - always

    - name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
        - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_rp_filter

    - name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
        - Find all files that contain net.ipv4.conf.all.rp_filter
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.all.rp_filter\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_rp_filter

    - name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
        - Find all files that set net.ipv4.conf.all.rp_filter to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.all.rp_filter\s*=\s*{{ sysctl_net_ipv4_conf_all_rp_filter_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_rp_filter

    - name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
        - Comment out any occurrences of net.ipv4.conf.all.rp_filter from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.conf.all.rp_filter
        replace: '#net.ipv4.conf.all.rp_filter'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_rp_filter

    - name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
        - Ensure sysctl net.ipv4.conf.all.rp_filter is set
      ansible.posix.sysctl:
        name: net.ipv4.conf.all.rp_filter
        value: '{{ sysctl_net_ipv4_conf_all_rp_filter_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_rp_filter
#### Rule Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces [ref]
To set the runtime status of the `net.ipv4.conf.all.secure_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.all.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.all.secure_redirects = 0
Rationale: | Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_secure_redirects
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cobit5 | APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-7(a), CM-7(b), CM-6(a), SC-7(a)
nist-csf | DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
pcidss | Req-1.4.3
os-srg | SRG-OS-000480-GPOS-00227
anssi | R12
cis | 3.3.3
pcidss4 | 1.4.3, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.conf.all.secure_redirects from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.secure_redirects.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.conf.all.secure_redirects" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_conf_all_secure_redirects_value='0'

    #
    # Set runtime for net.ipv4.conf.all.secure_redirects
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.conf.all.secure_redirects="$sysctl_net_ipv4_conf_all_secure_redirects_value"
    fi

    #
    # If net.ipv4.conf.all.secure_redirects present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.conf.all.secure_redirects = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.secure_redirects")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_all_secure_redirects_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.secure_redirects\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.secure_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_secure_redirects
    - name: XCCDF Value sysctl_net_ipv4_conf_all_secure_redirects_value # promote to variable
      set_fact:
        sysctl_net_ipv4_conf_all_secure_redirects_value: !!str 0
      tags:
        - always

    - name: Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
        - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_secure_redirects

    - name: Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
        - Find all files that contain net.ipv4.conf.all.secure_redirects
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.all.secure_redirects\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_secure_redirects

    - name: Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
        - Find all files that set net.ipv4.conf.all.secure_redirects to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.all.secure_redirects\s*=\s*{{ sysctl_net_ipv4_conf_all_secure_redirects_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_secure_redirects

    - name: Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
        - Comment out any occurrences of net.ipv4.conf.all.secure_redirects from config
        files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.conf.all.secure_redirects
        replace: '#net.ipv4.conf.all.secure_redirects'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_secure_redirects

    - name: Disable Kernel Parameter for Accepting Secure ICMP Redirects on all IPv4 Interfaces
        - Ensure sysctl net.ipv4.conf.all.secure_redirects is set
      ansible.posix.sysctl:
        name: net.ipv4.conf.all.secure_redirects
        value: '{{ sysctl_net_ipv4_conf_all_secure_redirects_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_secure_redirects
#### Rule Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces [ref]
To set the runtime status of the `net.ipv4.conf.default.accept_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.default.accept_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.default.accept_redirects = 0
Rationale: | ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_redirects
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cjis | 5.10.1.1
cobit5 | APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-7(a), CM-7(b), CM-6(a), SC-7(a)
nist-csf | DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
pcidss | Req-1.4.3
os-srg | SRG-OS-000480-GPOS-00227
anssi | R12
cis | 3.3.2
pcidss4 | 1.4.3, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.conf.default.accept_redirects from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.accept_redirects.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.conf.default.accept_redirects" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_conf_default_accept_redirects_value='0'

    #
    # Set runtime for net.ipv4.conf.default.accept_redirects
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.conf.default.accept_redirects="$sysctl_net_ipv4_conf_default_accept_redirects_value"
    fi

    #
    # If net.ipv4.conf.default.accept_redirects present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.conf.default.accept_redirects = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.accept_redirects")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_accept_redirects_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.accept_redirects\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.accept_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_accept_redirects
    - name: XCCDF Value sysctl_net_ipv4_conf_default_accept_redirects_value # promote to variable
      set_fact:
        sysctl_net_ipv4_conf_default_accept_redirects_value: !!str 0
      tags:
        - always

    - name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
        - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_accept_redirects

    - name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
        - Find all files that contain net.ipv4.conf.default.accept_redirects
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.default.accept_redirects\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_accept_redirects

    - name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
        - Find all files that set net.ipv4.conf.default.accept_redirects to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.default.accept_redirects\s*=\s*{{ sysctl_net_ipv4_conf_default_accept_redirects_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_accept_redirects

    - name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
        - Comment out any occurrences of net.ipv4.conf.default.accept_redirects from config
        files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.conf.default.accept_redirects
        replace: '#net.ipv4.conf.default.accept_redirects'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_accept_redirects

    - name: Disable Kernel Parameter for Accepting ICMP Redirects by Default on IPv4 Interfaces
        - Ensure sysctl net.ipv4.conf.default.accept_redirects is set
      ansible.posix.sysctl:
        name: net.ipv4.conf.default.accept_redirects
        value: '{{ sysctl_net_ipv4_conf_default_accept_redirects_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_accept_redirects
#### Rule Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces by Default [ref]
To set the runtime status of the `net.ipv4.conf.default.accept_source_route` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.default.accept_source_route=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.default.accept_source_route = 0
Rationale: | Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It should be disabled unless it is absolutely required, such as when IPv4 forwarding is enabled and the system is legitimately functioning as a router.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_accept_source_route
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cjis | 5.10.1.1
cobit5 | APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nist | CM-7(a), CM-7(b), SC-5, SC-7(a)
nist-csf | DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R12
cis | 3.3.1
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.conf.default.accept_source_route from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.accept_source_route.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.conf.default.accept_source_route" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_conf_default_accept_source_route_value='0'

    #
    # Set runtime for net.ipv4.conf.default.accept_source_route
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.conf.default.accept_source_route="$sysctl_net_ipv4_conf_default_accept_source_route_value"
    fi

    #
    # If net.ipv4.conf.default.accept_source_route present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.conf.default.accept_source_route = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.accept_source_route")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_accept_source_route_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.accept_source_route\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.accept_source_route\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_accept_source_route
    - name: XCCDF Value sysctl_net_ipv4_conf_default_accept_source_route_value # promote to variable
      set_fact:
        sysctl_net_ipv4_conf_default_accept_source_route_value: !!str 0
      tags:
        - always

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces
        by Default - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces
        by Default - Find all files that contain net.ipv4.conf.default.accept_source_route
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.default.accept_source_route\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces
        by Default - Find all files that set net.ipv4.conf.default.accept_source_route
        to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.default.accept_source_route\s*=\s*{{ sysctl_net_ipv4_conf_default_accept_source_route_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces
        by Default - Comment out any occurrences of net.ipv4.conf.default.accept_source_route
        from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.conf.default.accept_source_route
        replace: '#net.ipv4.conf.default.accept_source_route'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_accept_source_route

    - name: Disable Kernel Parameter for Accepting Source-Routed Packets on IPv4 Interfaces
        by Default - Ensure sysctl net.ipv4.conf.default.accept_source_route is set
      ansible.posix.sysctl:
        name: net.ipv4.conf.default.accept_source_route
        value: '{{ sysctl_net_ipv4_conf_default_accept_source_route_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_accept_source_route
#### Rule Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default [ref]
To set the runtime status of the `net.ipv4.conf.default.log_martians` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.default.log_martians=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.default.log_martians = 1
Rationale: | The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_log_martians
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9
cobit5 | APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.04, DSS03.05, DSS05.02, DSS05.03, DSS05.05, DSS05.07, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.11.2.6, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.2.1, A.6.2.2, A.9.1.2
nist | CM-7(a), CM-7(b), SC-5(3)(a)
nist-csf | DE.CM-1, PR.AC-3, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
cis | 3.3.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.conf.default.log_martians from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.log_martians.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.conf.default.log_martians" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_conf_default_log_martians_value='1'

    #
    # Set runtime for net.ipv4.conf.default.log_martians
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.conf.default.log_martians="$sysctl_net_ipv4_conf_default_log_martians_value"
    fi

    #
    # If net.ipv4.conf.default.log_martians present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.conf.default.log_martians = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.log_martians")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_log_martians_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.log_martians\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.log_martians\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(3)(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_conf_default_log_martians
      - unknown_severity
    - name: XCCDF Value sysctl_net_ipv4_conf_default_log_martians_value # promote to variable
      set_fact:
        sysctl_net_ipv4_conf_default_log_martians_value: !!str 1
      tags:
        - always

    - name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
        - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(3)(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_conf_default_log_martians
      - unknown_severity

    - name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
        - Find all files that contain net.ipv4.conf.default.log_martians
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.default.log_martians\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(3)(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_conf_default_log_martians
      - unknown_severity

    - name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
        - Find all files that set net.ipv4.conf.default.log_martians to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.default.log_martians\s*=\s*{{ sysctl_net_ipv4_conf_default_log_martians_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(3)(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_conf_default_log_martians
      - unknown_severity

    - name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
        - Comment out any occurrences of net.ipv4.conf.default.log_martians from config
        files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.conf.default.log_martians
        replace: '#net.ipv4.conf.default.log_martians'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(3)(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_conf_default_log_martians
      - unknown_severity

    - name: Enable Kernel Parameter to Log Martian Packets on all IPv4 Interfaces by Default
        - Ensure sysctl net.ipv4.conf.default.log_martians is set
      ansible.posix.sysctl:
        name: net.ipv4.conf.default.log_martians
        value: '{{ sysctl_net_ipv4_conf_default_log_martians_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(3)(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_conf_default_log_martians
      - unknown_severity
#### Rule Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces by Default [ref]
To set the runtime status of the `net.ipv4.conf.default.rp_filter` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.default.rp_filter=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.default.rp_filter = 1
Rationale: | Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface they were received on. It should not be used on systems which are routers for complicated networks, but is helpful for end hosts and routers serving small networks.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_rp_filter
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9
cobit5 | APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.4.3.3
isa-62443-2013 | SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-7(a), CM-7(b), CM-6(a), SC-7(a)
nist-csf | DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R12
cis | 3.3.7
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.conf.default.rp_filter from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.rp_filter.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.conf.default.rp_filter" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_conf_default_rp_filter_value='1'

    #
    # Set runtime for net.ipv4.conf.default.rp_filter
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.conf.default.rp_filter="$sysctl_net_ipv4_conf_default_rp_filter_value"
    fi

    #
    # If net.ipv4.conf.default.rp_filter present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.conf.default.rp_filter = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.rp_filter")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_rp_filter_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.rp_filter\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.rp_filter\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_rp_filter
    - name: XCCDF Value sysctl_net_ipv4_conf_default_rp_filter_value # promote to variable
      set_fact:
        sysctl_net_ipv4_conf_default_rp_filter_value: !!str 1
      tags:
        - always

    - name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
        by Default - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_rp_filter

    - name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
        by Default - Find all files that contain net.ipv4.conf.default.rp_filter
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.default.rp_filter\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_rp_filter

    - name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
        by Default - Find all files that set net.ipv4.conf.default.rp_filter to correct
        value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.default.rp_filter\s*=\s*{{ sysctl_net_ipv4_conf_default_rp_filter_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_rp_filter

    - name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
        by Default - Comment out any occurrences of net.ipv4.conf.default.rp_filter from
        config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.conf.default.rp_filter
        replace: '#net.ipv4.conf.default.rp_filter'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_rp_filter

    - name: Enable Kernel Parameter to Use Reverse Path Filtering on all IPv4 Interfaces
        by Default - Ensure sysctl net.ipv4.conf.default.rp_filter is set
      ansible.posix.sysctl:
        name: net.ipv4.conf.default.rp_filter
        value: '{{ sysctl_net_ipv4_conf_default_rp_filter_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_rp_filter
#### Rule Configure Kernel Parameter for Accepting Secure Redirects By Default [ref]
To set the runtime status of the `net.ipv4.conf.default.secure_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.default.secure_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.default.secure_redirects = 0
Rationale: | Accepting "secure" ICMP redirects (from those gateways listed as default gateways) has few legitimate uses. It should be disabled unless it is absolutely required.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_secure_redirects
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cobit5 | APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nist | CM-7(a), CM-7(b), SC-5, SC-7(a)
nist-csf | DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R12
cis | 3.3.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.conf.default.secure_redirects from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.secure_redirects.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.conf.default.secure_redirects" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_conf_default_secure_redirects_value='0'

    #
    # Set runtime for net.ipv4.conf.default.secure_redirects
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.conf.default.secure_redirects="$sysctl_net_ipv4_conf_default_secure_redirects_value"
    fi

    #
    # If net.ipv4.conf.default.secure_redirects present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.conf.default.secure_redirects = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.secure_redirects")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_conf_default_secure_redirects_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.secure_redirects\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.secure_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_secure_redirects
    - name: XCCDF Value sysctl_net_ipv4_conf_default_secure_redirects_value # promote to variable
      set_fact:
        sysctl_net_ipv4_conf_default_secure_redirects_value: !!str 0
      tags:
        - always

    - name: Configure Kernel Parameter for Accepting Secure Redirects By Default - Set
        fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_secure_redirects

    - name: Configure Kernel Parameter for Accepting Secure Redirects By Default - Find
        all files that contain net.ipv4.conf.default.secure_redirects
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.default.secure_redirects\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_secure_redirects

    - name: Configure Kernel Parameter for Accepting Secure Redirects By Default - Find
        all files that set net.ipv4.conf.default.secure_redirects to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.default.secure_redirects\s*=\s*{{ sysctl_net_ipv4_conf_default_secure_redirects_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_secure_redirects

    - name: Configure Kernel Parameter for Accepting Secure Redirects By Default - Comment
        out any occurrences of net.ipv4.conf.default.secure_redirects from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.conf.default.secure_redirects
        replace: '#net.ipv4.conf.default.secure_redirects'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_secure_redirects

    - name: Configure Kernel Parameter for Accepting Secure Redirects By Default - Ensure
        sysctl net.ipv4.conf.default.secure_redirects is set
      ansible.posix.sysctl:
        name: net.ipv4.conf.default.secure_redirects
        value: '{{ sysctl_net_ipv4_conf_default_secure_redirects_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_secure_redirects
#### Rule Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces [ref]
To set the runtime status of the `net.ipv4.icmp_echo_ignore_broadcasts` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.icmp_echo_ignore_broadcasts=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.icmp_echo_ignore_broadcasts = 1
Rationale: | Responding to broadcast (ICMP) echoes facilitates network mapping and provides a vector for amplification attacks. Ignoring ICMP echo requests (pings) sent to broadcast or multicast addresses makes the system slightly more difficult to enumerate on the network.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_echo_ignore_broadcasts
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cjis | 5.10.1.1
cobit5 | APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nist | CM-7(a), CM-7(b), SC-5
nist-csf | DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
pcidss | Req-1.4.3
os-srg | SRG-OS-000480-GPOS-00227
cis | 3.3.5
pcidss4 | 1.4.2, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.icmp_echo_ignore_broadcasts from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.icmp_echo_ignore_broadcasts.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.icmp_echo_ignore_broadcasts" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value='1'

    #
    # Set runtime for net.ipv4.icmp_echo_ignore_broadcasts
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.icmp_echo_ignore_broadcasts="$sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value"
    fi

    #
    # If net.ipv4.icmp_echo_ignore_broadcasts present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.icmp_echo_ignore_broadcasts = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.icmp_echo_ignore_broadcasts")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.icmp_echo_ignore_broadcasts\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.icmp_echo_ignore_broadcasts\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_icmp_echo_ignore_broadcasts
    - name: XCCDF Value sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value # promote to variable
      set_fact:
        sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value: !!str 1
      tags:
        - always

    - name: Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
        - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_icmp_echo_ignore_broadcasts

    - name: Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
        - Find all files that contain net.ipv4.icmp_echo_ignore_broadcasts
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.icmp_echo_ignore_broadcasts\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_icmp_echo_ignore_broadcasts

    - name: Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
        - Find all files that set net.ipv4.icmp_echo_ignore_broadcasts to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.icmp_echo_ignore_broadcasts\s*=\s*{{ sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_icmp_echo_ignore_broadcasts

    - name: Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
        - Comment out any occurrences of net.ipv4.icmp_echo_ignore_broadcasts from config
        files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.icmp_echo_ignore_broadcasts
        replace: '#net.ipv4.icmp_echo_ignore_broadcasts'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_icmp_echo_ignore_broadcasts

    - name: Enable Kernel Parameter to Ignore ICMP Broadcast Echo Requests on IPv4 Interfaces
        - Ensure sysctl net.ipv4.icmp_echo_ignore_broadcasts is set
      ansible.posix.sysctl:
        name: net.ipv4.icmp_echo_ignore_broadcasts
        value: '{{ sysctl_net_ipv4_icmp_echo_ignore_broadcasts_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_icmp_echo_ignore_broadcasts
#### Rule Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces [ref]
To set the runtime status of the `net.ipv4.icmp_ignore_bogus_error_responses` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.icmp_ignore_bogus_error_responses=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.icmp_ignore_bogus_error_responses = 1
Rationale: | Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_icmp_ignore_bogus_error_responses
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9
cobit5 | APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2
nerc-cip | CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nist | CM-7(a), CM-7(b), SC-5
nist-csf | DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3
pcidss | Req-1.4.3
os-srg | SRG-OS-000480-GPOS-00227
anssi | R12
cis | 3.3.6
pcidss4 | 1.4.2, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.icmp_ignore_bogus_error_responses from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.icmp_ignore_bogus_error_responses.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.icmp_ignore_bogus_error_responses" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value='1'

    #
    # Set runtime for net.ipv4.icmp_ignore_bogus_error_responses
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.icmp_ignore_bogus_error_responses="$sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value"
    fi

    #
    # If net.ipv4.icmp_ignore_bogus_error_responses present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.icmp_ignore_bogus_error_responses = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.icmp_ignore_bogus_error_responses")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.icmp_ignore_bogus_error_responses\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.icmp_ignore_bogus_error_responses\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
      - unknown_severity
    - name: XCCDF Value sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value # promote to variable
      set_fact:
        sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value: !!str 1
      tags:
        - always

    - name: Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
        - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
      - unknown_severity

    - name: Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
        - Find all files that contain net.ipv4.icmp_ignore_bogus_error_responses
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.icmp_ignore_bogus_error_responses\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
      - unknown_severity

    - name: Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
        - Find all files that set net.ipv4.icmp_ignore_bogus_error_responses to correct
        value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.icmp_ignore_bogus_error_responses\s*=\s*{{ sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
      - unknown_severity

    - name: Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
        - Comment out any occurrences of net.ipv4.icmp_ignore_bogus_error_responses from
        config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.icmp_ignore_bogus_error_responses
        replace: '#net.ipv4.icmp_ignore_bogus_error_responses'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
      - unknown_severity

    - name: Enable Kernel Parameter to Ignore Bogus ICMP Error Responses on IPv4 Interfaces
        - Ensure sysctl net.ipv4.icmp_ignore_bogus_error_responses is set
      ansible.posix.sysctl:
        name: net.ipv4.icmp_ignore_bogus_error_responses
        value: '{{ sysctl_net_ipv4_icmp_ignore_bogus_error_responses_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - PCI-DSS-Req-1.4.3
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - low_complexity
      - medium_disruption
      - reboot_required
      - sysctl_net_ipv4_icmp_ignore_bogus_error_responses
      - unknown_severity
#### Rule Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces [ref]
To set the runtime status of the `net.ipv4.tcp_syncookies` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.tcp_syncookies=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.tcp_syncookies = 1
Rationale: | A TCP SYN flood attack can cause a denial of service by filling a system's TCP connection table with connections in the SYN_RCVD state. Syncookies can be used to track a connection when a subsequent ACK is received, verifying the initiator is attempting a valid connection and is not a flood source. This feature is activated when a flood condition is detected, and enables the system to continue servicing valid connection requests.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_tcp_syncookies
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 18, 2, 4, 6, 7, 8, 9
cjis | 5.10.1.1
cobit5 | APO01.06, APO13.01, BAI04.04, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.07, DSS06.02
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.4.3.3
isa-62443-2013 | SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-7(a), CM-7(b), SC-5(1), SC-5(2), SC-5(3)(a), CM-6(a)
nist-csf | DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.PT-4
pcidss | Req-1.4.1
os-srg | SRG-OS-000480-GPOS-00227, SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00071
anssi | R12
cis | 3.3.8
pcidss4 | 1.4.3, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.tcp_syncookies from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.tcp_syncookies.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.tcp_syncookies" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    sysctl_net_ipv4_tcp_syncookies_value='1'

    #
    # Set runtime for net.ipv4.tcp_syncookies
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.tcp_syncookies="$sysctl_net_ipv4_tcp_syncookies_value"
    fi

    #
    # If net.ipv4.tcp_syncookies present in /etc/sysctl.conf, change value to appropriate value
    #	else, add "net.ipv4.tcp_syncookies = value" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.tcp_syncookies")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$sysctl_net_ipv4_tcp_syncookies_value"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.tcp_syncookies\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.tcp_syncookies\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(1)
      - NIST-800-53-SC-5(2)
      - NIST-800-53-SC-5(3)(a)
      - PCI-DSS-Req-1.4.1
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_tcp_syncookies
    - name: XCCDF Value sysctl_net_ipv4_tcp_syncookies_value # promote to variable
      set_fact:
        sysctl_net_ipv4_tcp_syncookies_value: !!str 1
      tags:
        - always

    - name: Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces - Set
        fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(1)
      - NIST-800-53-SC-5(2)
      - NIST-800-53-SC-5(3)(a)
      - PCI-DSS-Req-1.4.1
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_tcp_syncookies

    - name: Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces - Find
        all files that contain net.ipv4.tcp_syncookies
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.tcp_syncookies\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(1)
      - NIST-800-53-SC-5(2)
      - NIST-800-53-SC-5(3)(a)
      - PCI-DSS-Req-1.4.1
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_tcp_syncookies

    - name: Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces - Find
        all files that set net.ipv4.tcp_syncookies to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.tcp_syncookies\s*=\s*{{ sysctl_net_ipv4_tcp_syncookies_value
          }}$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(1)
      - NIST-800-53-SC-5(2)
      - NIST-800-53-SC-5(3)(a)
      - PCI-DSS-Req-1.4.1
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_tcp_syncookies

    - name: Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces - Comment
        out any occurrences of net.ipv4.tcp_syncookies from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.tcp_syncookies
        replace: '#net.ipv4.tcp_syncookies'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(1)
      - NIST-800-53-SC-5(2)
      - NIST-800-53-SC-5(3)(a)
      - PCI-DSS-Req-1.4.1
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_tcp_syncookies

    - name: Enable Kernel Parameter to Use TCP Syncookies on Network Interfaces - Ensure
        sysctl net.ipv4.tcp_syncookies is set
      ansible.posix.sysctl:
        name: net.ipv4.tcp_syncookies
        value: '{{ sysctl_net_ipv4_tcp_syncookies_value }}'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5(1)
      - NIST-800-53-SC-5(2)
      - NIST-800-53-SC-5(3)(a)
      - PCI-DSS-Req-1.4.1
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_tcp_syncookies
Group Network Parameters for Hosts Only Group contains 3 rules
[ref] If the system is not going to be used as a router, then setting certain kernel parameters ensure that the host will not perform routing of network traffic.
#### Rule Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces [ref]
To set the runtime status of the `net.ipv4.conf.all.send_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.all.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.all.send_redirects = 0
Rationale: | ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology. The ability to send ICMP redirects is only appropriate for systems acting as routers.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_all_send_redirects
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cjis | 5.10.1.1
cobit5 | APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nist | CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a)
nist-csf | DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R12
cis | 3.2.2
pcidss4 | 1.4.5, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.conf.all.send_redirects from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.all.send_redirects.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.conf.all.send_redirects" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    #
    # Set runtime for net.ipv4.conf.all.send_redirects
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.conf.all.send_redirects="0"
    fi

    #
    # If net.ipv4.conf.all.send_redirects present in /etc/sysctl.conf, change value to "0"
    #	else, add "net.ipv4.conf.all.send_redirects = 0" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.all.send_redirects")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "0"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.all.send_redirects\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.all.send_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.5
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_send_redirects

    - name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
        - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.5
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_send_redirects

    - name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
        - Find all files that contain net.ipv4.conf.all.send_redirects
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.all.send_redirects\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.5
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_send_redirects

    - name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
        - Find all files that set net.ipv4.conf.all.send_redirects to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.all.send_redirects\s*=\s*0$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.5
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_send_redirects

    - name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
        - Comment out any occurrences of net.ipv4.conf.all.send_redirects from config
        files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.conf.all.send_redirects
        replace: '#net.ipv4.conf.all.send_redirects'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.5
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_send_redirects

    - name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
        - Ensure sysctl net.ipv4.conf.all.send_redirects is set to 0
      ansible.posix.sysctl:
        name: net.ipv4.conf.all.send_redirects
        value: '0'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.5
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_all_send_redirects
#### Rule Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces by Default [ref]
To set the runtime status of the `net.ipv4.conf.default.send_redirects` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.conf.default.send_redirects=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.conf.default.send_redirects = 0
Rationale: | ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology. The ability to send ICMP redirects is only appropriate for systems acting as routers.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_conf_default_send_redirects
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 2, 3, 4, 6, 7, 8, 9
cjis | 5.10.1.1
cobit5 | APO01.06, APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS01.05, DSS03.01, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.2.3.4, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nist | CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a)
nist-csf | DE.AE-1, DE.CM-1, ID.AM-3, PR.AC-5, PR.DS-4, PR.DS-5, PR.IP-1, PR.PT-3, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R12
cis | 3.2.2
pcidss4 | 1.4.5, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.conf.default.send_redirects from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.conf.default.send_redirects.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.conf.default.send_redirects" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    #
    # Set runtime for net.ipv4.conf.default.send_redirects
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.conf.default.send_redirects="0"
    fi

    #
    # If net.ipv4.conf.default.send_redirects present in /etc/sysctl.conf, change value to "0"
    #	else, add "net.ipv4.conf.default.send_redirects = 0" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.conf.default.send_redirects")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "0"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.conf.default.send_redirects\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.conf.default.send_redirects\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.5
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_send_redirects

    - name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
        by Default - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.5
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_send_redirects

    - name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
        by Default - Find all files that contain net.ipv4.conf.default.send_redirects
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.default.send_redirects\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.5
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_send_redirects

    - name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
        by Default - Find all files that set net.ipv4.conf.default.send_redirects to correct
        value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.conf.default.send_redirects\s*=\s*0$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.5
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_send_redirects

    - name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
        by Default - Comment out any occurrences of net.ipv4.conf.default.send_redirects
        from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.conf.default.send_redirects
        replace: '#net.ipv4.conf.default.send_redirects'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.5
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_send_redirects

    - name: Disable Kernel Parameter for Sending ICMP Redirects on all IPv4 Interfaces
        by Default - Ensure sysctl net.ipv4.conf.default.send_redirects is set to 0
      ansible.posix.sysctl:
        name: net.ipv4.conf.default.send_redirects
        value: '0'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1.1
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.5
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_conf_default_send_redirects
#### Rule Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces [ref]
To set the runtime status of the `net.ipv4.ip_forward` kernel parameter, run the following command:
    $ sudo sysctl -w net.ipv4.ip_forward=0
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    net.ipv4.ip_forward = 0
Warning: Certain technologies such as virtual machines, containers, etc. rely on IPv4 forwarding to enable and use networking. Disabling IPv4 forwarding would cause those technologies to stop working. Therefore, this rule should not be used in profiles or benchmarks that target usage of IPv4 forwarding.
Rationale: | Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this capability is used when not required, system network information may be unnecessarily transmitted across the network.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_net_ipv4_ip_forward
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 2, 3, 7, 8, 9
cobit5 | APO13.01, BAI04.04, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.03, DSS03.05, DSS05.02, DSS05.05, DSS05.07, DSS06.06
cui | 3.1.20
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.2, SR 7.1, SR 7.2, SR 7.6
iso27001-2013 | A.12.1.2, A.12.1.3, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.17.2.1, A.9.1.2
nerc-cip | CIP-007-3 R4, CIP-007-3 R4.1, CIP-007-3 R4.2, CIP-007-3 R5.1
nist | CM-7(a), CM-7(b), SC-5, CM-6(a), SC-7(a)
nist-csf | DE.CM-1, PR.DS-4, PR.IP-1, PR.PT-3, PR.PT-4
pcidss | Req-1.3.1, Req-1.3.2
os-srg | SRG-OS-000480-GPOS-00227
anssi | R12
cis | 3.2.1
pcidss4 | 1.4.3, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of net.ipv4.ip_forward from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*net.ipv4.ip_forward.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "net.ipv4.ip_forward" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    #
    # Set runtime for net.ipv4.ip_forward
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w net.ipv4.ip_forward="0"
    fi

    #
    # If net.ipv4.ip_forward present in /etc/sysctl.conf, change value to "0"
    #	else, add "net.ipv4.ip_forward = 0" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^net.ipv4.ip_forward")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "0"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^net.ipv4.ip_forward\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^net.ipv4.ip_forward\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.3.1
      - PCI-DSS-Req-1.3.2
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_ip_forward

    - name: Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces - Set fact for
        sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.3.1
      - PCI-DSS-Req-1.3.2
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_ip_forward

    - name: Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces - Find all files
        that contain net.ipv4.ip_forward
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.ip_forward\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.3.1
      - PCI-DSS-Req-1.3.2
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_ip_forward

    - name: Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces - Find all files
        that set net.ipv4.ip_forward to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*net.ipv4.ip_forward\s*=\s*0$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.3.1
      - PCI-DSS-Req-1.3.2
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_ip_forward

    - name: Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces - Comment out
        any occurrences of net.ipv4.ip_forward from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*net.ipv4.ip_forward
        replace: '#net.ipv4.ip_forward'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.3.1
      - PCI-DSS-Req-1.3.2
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_ip_forward

    - name: Disable Kernel Parameter for IP Forwarding on IPv4 Interfaces - Ensure sysctl
        net.ipv4.ip_forward is set to 0
      ansible.posix.sysctl:
        name: net.ipv4.ip_forward
        value: '0'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.20
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-SC-5
      - NIST-800-53-SC-7(a)
      - PCI-DSS-Req-1.3.1
      - PCI-DSS-Req-1.3.2
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.3
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_net_ipv4_ip_forward
Group nftables Group contains 3 rules
[ref] `If firewalld or iptables are being used in your environment, please follow the guidance in their respective section and pass-over the guidance in this section.` nftables is a subsystem of the Linux kernel providing filtering and classification of network packets/datagrams/frames and is the successor to iptables. The biggest change with the successor nftables is its simplicity. With iptables, we have to configure every single rule and use the syntax which can be compared with normal commands. With nftables, the simpler syntax, much like BPF (Berkely Packet Filter) means shorter lines and less repetition. Support for nftables should also be compiled into the kernel, together with the related nftables modules. It is available in Linux kernels >= 3.13. Please ensure that your kernel supports nftables before choosing this option.
#### Rule Install nftables Package [ref]
nftables provides a new in-kernel packet classification framework that is based on a network-specific Virtual Machine (VM) and a new nft userspace command line tool. nftables reuses the existing Netfilter subsystems such as the existing hook infrastructure, the connection tracking system, NAT, userspace queuing and logging subsystem. The `nftables` package can be installed with the following command:
    $ sudo dnf install nftables
Rationale: | `nftables` is a subsystem of the Linux kernel that can protect against threats originating from within a corporate network to include malicious mobile code and poorly configured software on a host.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_package_nftables_installed
References: |
cis | 3.4.1.1
pcidss4 | 1.2.1, 1.2
Remediation OSBuild Blueprint snippet ⇲
    [[packages]]
    name = "nftables"
    version = "*"
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if ( ( ! (systemctl is-active iptables &>/dev/null) && ! (systemctl is-active ufw &>/dev/null) && rpm --quiet -q kernel ) ); then

    if ! rpm -q --quiet "nftables" ; then
        dnf install -y "nftables"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    package --add=nftables
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.1
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_nftables_installed

    - name: Ensure nftables is installed
      ansible.builtin.package:
        name: nftables
        state: present
      when: ( "kernel" in ansible_facts.packages )
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.1
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_nftables_installed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include install_nftables

    class install_nftables {
      package { 'nftables':
        ensure => 'installed',
      }
    }
#### Rule Verify nftables Service is Disabled [ref]
nftables is a subsystem of the Linux kernel providing filtering and classification of network packets/datagrams/frames and is the successor to iptables. The `nftables` service can be disabled with the following command:
    systemctl disable nftables
Rationale: | Running both `firewalld` and `nftables` may lead to conflict. `nftables` is actually one of the backends for `firewalld` management tools.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_service_nftables_disabled
References: |
cis | 3.4.1.2
pcidss4 | 1.2.1, 1.2
Remediation OSBuild Blueprint snippet ⇲
    [customizations.services]
    masked = ["nftables"]
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if ( ( rpm --quiet -q firewalld && rpm --quiet -q nftables && rpm --quiet -q kernel ) ); then

    SYSTEMCTL_EXEC='/usr/bin/systemctl'
    if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
      "$SYSTEMCTL_EXEC" stop 'nftables.service'
    fi
    "$SYSTEMCTL_EXEC" disable 'nftables.service'
    "$SYSTEMCTL_EXEC" mask 'nftables.service'
    # Disable socket activation if we have a unit file for it
    if "$SYSTEMCTL_EXEC" -q list-unit-files nftables.socket; then
        if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
          "$SYSTEMCTL_EXEC" stop 'nftables.socket'
        fi
        "$SYSTEMCTL_EXEC" mask 'nftables.socket'
    fi
    # The service may not be running because it has been started and failed,
    # so let's reset the state so OVAL checks pass.
    # Service should be 'inactive', not 'failed' after reboot though.
    "$SYSTEMCTL_EXEC" reset-failed 'nftables.service' || true

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.1
      - disable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_nftables_disabled

    - name: Verify nftables Service is Disabled - Disable service nftables
      block:

      - name: Verify nftables Service is Disabled - Collect systemd Services Present in
          the System
        ansible.builtin.command: systemctl -q list-unit-files --type service
        register: service_exists
        changed_when: false
        failed_when: service_exists.rc not in [0, 1]
        check_mode: false

      - name: Verify nftables Service is Disabled - Ensure nftables.service is Masked
        ansible.builtin.systemd:
          name: nftables.service
          state: stopped
          enabled: false
          masked: true
        when: service_exists.stdout_lines is search("nftables.service", multiline=True)

      - name: Unit Socket Exists - nftables.socket
        ansible.builtin.command: systemctl -q list-unit-files nftables.socket
        register: socket_file_exists
        changed_when: false
        failed_when: socket_file_exists.rc not in [0, 1]
        check_mode: false

      - name: Verify nftables Service is Disabled - Disable Socket nftables
        ansible.builtin.systemd:
          name: nftables.socket
          enabled: false
          state: stopped
          masked: true
        when: socket_file_exists.stdout_lines is search("nftables.socket", multiline=True)
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.1
      - disable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_nftables_disabled
      - special_service_block
      when: ( "firewalld" in ansible_facts.packages and "nftables" in ansible_facts.packages
        and "kernel" in ansible_facts.packages )
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include disable_nftables

    class disable_nftables {
      service {'nftables':
        enable => false,
        ensure => 'stopped',
      }
    }
#### Rule Ensure a Table Exists for Nftables [ref]
Tables in nftables hold chains. Each table only has one address family and only applies to packets of this family. Tables can have one of six families. Warning: Adding or editing rules in a running nftables can cause loss of connectivity to the system. Warning: Both the SCE check and remediation for this rule only consider runtime settings. There is no specific file to check as it depends on each site's policy. Therefore, check and remediation use the nft command directly. The fix is not persistent across system reboots. Warning: SCE check does not support variables, therefore the SCE check in this rule only checks the address family, regardless of the table name.
Rationale: | Nftables doesn't have any default tables. Without a table being built, nftables will not filter network traffic.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_set_nftables_table
References: |
cis | 3.4.2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q nftables; then

    var_nftables_family='inet'

    var_nftables_table='firewalld'

    if ! nft list table $var_nftables_family $var_nftables_table; then
      nft create table "$var_nftables_family" "$var_nftables_table"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - set_nftables_table
    - name: XCCDF Value var_nftables_family # promote to variable
      set_fact:
        var_nftables_family: !!str inet
      tags:
        - always
    - name: XCCDF Value var_nftables_table # promote to variable
      set_fact:
        var_nftables_table: !!str firewalld
      tags:
        - always

    - name: Collect Existing Nftables
      ansible.builtin.command: nft list table {{ var_nftables_family }} {{ var_nftables_table
        }}
      register: result_nftables_table_family
      changed_when: false
      failed_when: result_nftables_table_family.rc not in [0, 1]
      when: '"nftables" in ansible_facts.packages'
      tags:
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - set_nftables_table

    - name: Set Nftable Table
      ansible.builtin.command: nft create table {{ var_nftables_family }} {{ var_nftables_table
        }}
      when:
      - '"nftables" in ansible_facts.packages'
      - result_nftables_table_family is not skipped
      - result_nftables_table_family.rc != 0
      tags:
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - set_nftables_table
Group Uncommon Network Protocols Group contains 4 rules
[ref] The system includes support for several network protocols which are not commonly used. Although security vulnerabilities in kernel networking code are not frequently discovered, the consequences can be dramatic. Ensuring uncommon network protocols are disabled reduces the system's risk to attacks targeted at its implementation of those protocols. Warning: Although these protocols are not commonly used, avoid disruption in your network environment by ensuring they are not needed prior to disabling them.
#### Rule Disable DCCP Support [ref]
The Datagram Congestion Control Protocol (DCCP) is a relatively new transport layer protocol, designed to support streaming media and telephony. To configure the system to prevent the `dccp` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/dccp.conf`:
    install dccp /bin/false
This entry will cause a non-zero return value during a `dccp` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):
    install dccp /bin/true
Rationale: | Disabling DCCP protects the system against exploitation of any flaws in its implementation.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_dccp_disabled
References: |
cis-csc | 11, 14, 3, 9
cjis | 5.10.1
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.4.6
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
pcidss | Req-1.4.2
os-srg | SRG-OS-000096-GPOS-00050, SRG-OS-000378-GPOS-00163
cis | 3.1.2
pcidss4 | 1.4.2, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if LC_ALL=C grep -q -m 1 "^install dccp" /etc/modprobe.d/dccp.conf ; then

    	sed -i 's#^install dccp.*#install dccp /bin/false#g' /etc/modprobe.d/dccp.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/dccp.conf
    	echo "install dccp /bin/false" >> /etc/modprobe.d/dccp.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.1
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.2
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - kernel_module_dccp_disabled
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required

    - name: Ensure kernel module 'dccp' is disabled
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/modprobe.d/dccp.conf
        regexp: install\s+dccp
        line: install dccp /bin/false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.2
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - kernel_module_dccp_disabled
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
#### Rule Disable RDS Support [ref]
The Reliable Datagram Sockets (RDS) protocol is a transport layer protocol designed to provide reliable high-bandwidth, low-latency communications between nodes in a cluster. To configure the system to prevent the `rds` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/rds.conf`:
    install rds /bin/false
This entry will cause a non-zero return value during a `rds` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):
    install rds /bin/true
Rationale: | Disabling RDS protects the system against exploitation of any flaws in its implementation.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_rds_disabled
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 3.1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if LC_ALL=C grep -q -m 1 "^install rds" /etc/modprobe.d/rds.conf ; then

    	sed -i 's#^install rds.*#install rds /bin/false#g' /etc/modprobe.d/rds.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/rds.conf
    	echo "install rds /bin/false" >> /etc/modprobe.d/rds.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_rds_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required

    - name: Ensure kernel module 'rds' is disabled
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/modprobe.d/rds.conf
        regexp: install\s+rds
        line: install rds /bin/false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_rds_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required
#### Rule Disable SCTP Support [ref]
The Stream Control Transmission Protocol (SCTP) is a transport layer protocol, designed to support the idea of message-oriented communication, with several streams of messages within one connection. To configure the system to prevent the `sctp` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/sctp.conf`:
    install sctp /bin/false
This entry will cause a non-zero return value during a `sctp` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):
    install sctp /bin/true
Rationale: | Disabling SCTP protects the system against exploitation of any flaws in its implementation.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_sctp_disabled
References: |
cis-csc | 11, 14, 3, 9
cjis | 5.10.1
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.4.6
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
ospp | FMT_SMF_EXT.1
pcidss | Req-1.4.2
os-srg | SRG-OS-000095-GPOS-00049, SRG-OS-000480-GPOS-00227
cis | 3.1.3
pcidss4 | 1.4.2, 1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if LC_ALL=C grep -q -m 1 "^install sctp" /etc/modprobe.d/sctp.conf ; then

    	sed -i 's#^install sctp.*#install sctp /bin/false#g' /etc/modprobe.d/sctp.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/sctp.conf
    	echo "install sctp /bin/false" >> /etc/modprobe.d/sctp.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.10.1
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.2
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - kernel_module_sctp_disabled
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required

    - name: Ensure kernel module 'sctp' is disabled
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/modprobe.d/sctp.conf
        regexp: install\s+sctp
        line: install sctp /bin/false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.10.1
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-1.4.2
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - disable_strategy
      - kernel_module_sctp_disabled
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
#### Rule Disable TIPC Support [ref]
The Transparent Inter-Process Communication (TIPC) protocol is designed to provide communications between nodes in a cluster. To configure the system to prevent the `tipc` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/tipc.conf`:
    install tipc /bin/false
This entry will cause a non-zero return value during a `tipc` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):
    install tipc /bin/true
Warning: This configuration baseline was created to deploy the base operating system for general purpose workloads. When the operating system is configured for certain purposes, such as a node in High Performance Computing cluster, it is expected that the `tipc` kernel module will be loaded.
Rationale: | Disabling TIPC protects the system against exploitation of any flaws in its implementation.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_tipc_disabled
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
ospp | FMT_SMF_EXT.1
os-srg | SRG-OS-000095-GPOS-00049
cis | 3.1.5
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if LC_ALL=C grep -q -m 1 "^install tipc" /etc/modprobe.d/tipc.conf ; then

    	sed -i 's#^install tipc.*#install tipc /bin/false#g' /etc/modprobe.d/tipc.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/tipc.conf
    	echo "install tipc /bin/false" >> /etc/modprobe.d/tipc.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_tipc_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required

    - name: Ensure kernel module 'tipc' is disabled
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/modprobe.d/tipc.conf
        regexp: install\s+tipc
        line: install tipc /bin/false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_tipc_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required
Group File Permissions and Masks Group contains 7 groups and 59 rules
[ref] Traditional Unix security relies heavily on file and directory permissions to prevent unauthorized users from reading or modifying files to which they should not have access. Several of the commands in this section search filesystems for files or directories with certain characteristics, and are intended to be run on every local partition on a given system. When the variable PART appears in one of the commands below, it means that the command is intended to be run repeatedly, with the name of each local partition substituted for PART in turn. The following command prints a list of all xfs partitions on the local system, which is the default filesystem for Amazon Linux 2023 installations:
    $ mount -t xfs | awk '{print $3}'
For any systems that use a different local filesystem type, modify this command as appropriate.
Group Verify Permissions on Important Files and Directories Group contains 1 group and 28 rules
[ref] Permissions for many files on a system must be set restrictively to ensure sensitive information is properly protected. This section discusses important permission restrictions which can be verified to ensure that no harmful discrepancies have arisen.
Group Verify Permissions on Files with Local Account Information and Credentials Group contains 24 rules
[ref] The default restrictive permissions for files which act as important security databases such as `passwd`, `shadow`, `group`, and `gshadow` files must be maintained. Many utilities need read access to the `passwd` file in order to function properly, but read access to the `shadow` file allows malicious attacks against system passwords, and should never be enabled.
#### Rule Verify Group Who Owns Backup group File [ref]
To properly set the group owner of `/etc/group-`, run the command:
    $ sudo chgrp root /etc/group-
Rationale: | The `/etc/group-` file is a backup file of `/etc/group`, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_group
References: |
nist | AC-6 (1)
pcidss | Req-8.7
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.1.5
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/group-" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/group-
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_groupowner_backup_etc_group_newgroup variable if represented
        by gid
      ansible.builtin.set_fact:
        file_groupowner_backup_etc_group_newgroup: '0'
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_backup_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/group-
      ansible.builtin.stat:
        path: /etc/group-
      register: file_exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_backup_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/group-
      ansible.builtin.file:
        path: /etc/group-
        follow: false
        group: '{{ file_groupowner_backup_etc_group_newgroup }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_backup_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns Backup gshadow File [ref]
To properly set the group owner of `/etc/gshadow-`, run the command:
    $ sudo chgrp root /etc/gshadow-
Rationale: | The `/etc/gshadow-` file is a backup of `/etc/gshadow`, and as such, it contains group password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_gshadow
References: |
nist | AC-6 (1)
pcidss | Req-8.7
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.1.9
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/gshadow-" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/gshadow-
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_groupowner_backup_etc_gshadow_newgroup variable if represented
        by gid
      ansible.builtin.set_fact:
        file_groupowner_backup_etc_gshadow_newgroup: '0'
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7
      - configure_strategy
      - file_groupowner_backup_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/gshadow-
      ansible.builtin.stat:
        path: /etc/gshadow-
      register: file_exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7
      - configure_strategy
      - file_groupowner_backup_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/gshadow-
      ansible.builtin.file:
        path: /etc/gshadow-
        follow: false
        group: '{{ file_groupowner_backup_etc_gshadow_newgroup }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7
      - configure_strategy
      - file_groupowner_backup_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns Backup passwd File [ref]
To properly set the group owner of `/etc/passwd-`, run the command:
    $ sudo chgrp root /etc/passwd-
Rationale: | The `/etc/passwd-` file is a backup file of `/etc/passwd`, and as such, it contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_passwd
References: |
nist | AC-6 (1)
pcidss | Req-8.7
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.1.3
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/passwd-" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/passwd-
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_groupowner_backup_etc_passwd_newgroup variable if represented
        by gid
      ansible.builtin.set_fact:
        file_groupowner_backup_etc_passwd_newgroup: '0'
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_backup_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/passwd-
      ansible.builtin.stat:
        path: /etc/passwd-
      register: file_exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_backup_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/passwd-
      ansible.builtin.file:
        path: /etc/passwd-
        follow: false
        group: '{{ file_groupowner_backup_etc_passwd_newgroup }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_backup_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify User Who Owns Backup shadow File [ref]
To properly set the group owner of `/etc/shadow-`, run the command:
    $ sudo chgrp root /etc/shadow-
Rationale: | The `/etc/shadow-` file is a backup file of `/etc/shadow`, and as such, it contains the list of local system accounts and password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_backup_etc_shadow
References: |
pcidss | Req-8.7
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.1.7
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/shadow-" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/shadow-
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_groupowner_backup_etc_shadow_newgroup variable if represented
        by gid
      ansible.builtin.set_fact:
        file_groupowner_backup_etc_shadow_newgroup: '0'
      tags:
      - PCI-DSS-Req-8.7
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_backup_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/shadow-
      ansible.builtin.stat:
        path: /etc/shadow-
      register: file_exists
      tags:
      - PCI-DSS-Req-8.7
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_backup_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/shadow-
      ansible.builtin.file:
        path: /etc/shadow-
        follow: false
        group: '{{ file_groupowner_backup_etc_shadow_newgroup }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - PCI-DSS-Req-8.7
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_backup_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns group File [ref]
To properly set the group owner of `/etc/group`, run the command:
    $ sudo chgrp root /etc/group
Rationale: | The `/etc/group` file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_etc_group
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.1.4
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/group" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/group
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_groupowner_etc_group_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_etc_group_newgroup: '0'
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/group
      ansible.builtin.stat:
        path: /etc/group
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/group
      ansible.builtin.file:
        path: /etc/group
        follow: false
        group: '{{ file_groupowner_etc_group_newgroup }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns gshadow File [ref]
To properly set the group owner of `/etc/gshadow`, run the command:
    $ sudo chgrp root /etc/gshadow
Rationale: | The `/etc/gshadow` file contains group password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_etc_gshadow
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.1.8
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/gshadow" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/gshadow
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_groupowner_etc_gshadow_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_etc_gshadow_newgroup: '0'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_groupowner_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/gshadow
      ansible.builtin.stat:
        path: /etc/gshadow
      register: file_exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_groupowner_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/gshadow
      ansible.builtin.file:
        path: /etc/gshadow
        follow: false
        group: '{{ file_groupowner_etc_gshadow_newgroup }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_groupowner_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns passwd File [ref]
To properly set the group owner of `/etc/passwd`, run the command:
    $ sudo chgrp root /etc/passwd
Rationale: | The `/etc/passwd` file contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_etc_passwd
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.1.1, 6.1.2
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/passwd" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/passwd
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_groupowner_etc_passwd_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_etc_passwd_newgroup: '0'
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/passwd
      ansible.builtin.stat:
        path: /etc/passwd
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/passwd
      ansible.builtin.file:
        path: /etc/passwd
        follow: false
        group: '{{ file_groupowner_etc_passwd_newgroup }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns shadow File [ref]
To properly set the group owner of `/etc/shadow`, run the command:
    $ sudo chgrp root /etc/shadow
Rationale: | The `/etc/shadow` file stores password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_etc_shadow
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.1.6
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/shadow" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/shadow
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_groupowner_etc_shadow_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_etc_shadow_newgroup: '0'
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/shadow
      ansible.builtin.stat:
        path: /etc/shadow
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/shadow
      ansible.builtin.file:
        path: /etc/shadow
        follow: false
        group: '{{ file_groupowner_etc_shadow_newgroup }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify User Who Owns Backup group File [ref]
To properly set the owner of `/etc/group-`, run the command:
    $ sudo chown root /etc/group-
Rationale: | The `/etc/group-` file is a backup file of `/etc/group`, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_backup_etc_group
References: |
nist | AC-6 (1)
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.1.5
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/group-" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/group-
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_owner_backup_etc_group_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_backup_etc_group_newown: '0'
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_backup_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/group-
      ansible.builtin.stat:
        path: /etc/group-
      register: file_exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_backup_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/group-
      ansible.builtin.file:
        path: /etc/group-
        follow: false
        owner: '{{ file_owner_backup_etc_group_newown }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_backup_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify User Who Owns Backup gshadow File [ref]
To properly set the owner of `/etc/gshadow-`, run the command:
    $ sudo chown root /etc/gshadow-
Rationale: | The `/etc/gshadow-` file is a backup of `/etc/gshadow`, and as such, it contains group password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_backup_etc_gshadow
References: |
nist | AC-6 (1)
pcidss | Req-8.7
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.1.9
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/gshadow-" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/gshadow-
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_owner_backup_etc_gshadow_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_backup_etc_gshadow_newown: '0'
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7
      - configure_strategy
      - file_owner_backup_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/gshadow-
      ansible.builtin.stat:
        path: /etc/gshadow-
      register: file_exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7
      - configure_strategy
      - file_owner_backup_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/gshadow-
      ansible.builtin.file:
        path: /etc/gshadow-
        follow: false
        owner: '{{ file_owner_backup_etc_gshadow_newown }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7
      - configure_strategy
      - file_owner_backup_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify User Who Owns Backup passwd File [ref]
To properly set the owner of `/etc/passwd-`, run the command:
    $ sudo chown root /etc/passwd-
Rationale: | The `/etc/passwd-` file is a backup file of `/etc/passwd`, and as such, it contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_backup_etc_passwd
References: |
nist | AC-6 (1)
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.1.3
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/passwd-" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/passwd-
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_owner_backup_etc_passwd_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_backup_etc_passwd_newown: '0'
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_backup_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/passwd-
      ansible.builtin.stat:
        path: /etc/passwd-
      register: file_exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_backup_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/passwd-
      ansible.builtin.file:
        path: /etc/passwd-
        follow: false
        owner: '{{ file_owner_backup_etc_passwd_newown }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_backup_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns Backup shadow File [ref]
To properly set the owner of `/etc/shadow-`, run the command:
    $ sudo chown root /etc/shadow-
Rationale: | The `/etc/shadow-` file is a backup file of `/etc/shadow`, and as such, it contains the list of local system accounts and password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_backup_etc_shadow
References: |
nist | AC-6 (1)
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.1.7
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/shadow-" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/shadow-
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_owner_backup_etc_shadow_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_backup_etc_shadow_newown: '0'
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_backup_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/shadow-
      ansible.builtin.stat:
        path: /etc/shadow-
      register: file_exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_backup_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/shadow-
      ansible.builtin.file:
        path: /etc/shadow-
        follow: false
        owner: '{{ file_owner_backup_etc_shadow_newown }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_backup_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify User Who Owns group File [ref]
To properly set the owner of `/etc/group`, run the command:
    $ sudo chown root /etc/group
Rationale: | The `/etc/group` file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_etc_group
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.1.4
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/group" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/group
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_owner_etc_group_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_etc_group_newown: '0'
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/group
      ansible.builtin.stat:
        path: /etc/group
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/group
      ansible.builtin.file:
        path: /etc/group
        follow: false
        owner: '{{ file_owner_etc_group_newown }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify User Who Owns gshadow File [ref]
To properly set the owner of `/etc/gshadow`, run the command:
    $ sudo chown root /etc/gshadow
Rationale: | The `/etc/gshadow` file contains group password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_etc_gshadow
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.1.8
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/gshadow" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/gshadow
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_owner_etc_gshadow_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_etc_gshadow_newown: '0'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_owner_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/gshadow
      ansible.builtin.stat:
        path: /etc/gshadow
      register: file_exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_owner_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/gshadow
      ansible.builtin.file:
        path: /etc/gshadow
        follow: false
        owner: '{{ file_owner_etc_gshadow_newown }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_owner_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify User Who Owns passwd File [ref]
To properly set the owner of `/etc/passwd`, run the command:
    $ sudo chown root /etc/passwd
Rationale: | The `/etc/passwd` file contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_etc_passwd
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.1.1, 6.1.2
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/passwd" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/passwd
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_owner_etc_passwd_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_etc_passwd_newown: '0'
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/passwd
      ansible.builtin.stat:
        path: /etc/passwd
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/passwd
      ansible.builtin.file:
        path: /etc/passwd
        follow: false
        owner: '{{ file_owner_etc_passwd_newown }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify User Who Owns shadow File [ref]
To properly set the owner of `/etc/shadow`, run the command:
    $ sudo chown root /etc/shadow
Rationale: | The `/etc/shadow` file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_etc_shadow
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.1.6
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/shadow" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/shadow
    fi

    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Set the file_owner_etc_shadow_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_etc_shadow_newown: '0'
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/shadow
      ansible.builtin.stat:
        path: /etc/shadow
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/shadow
      ansible.builtin.file:
        path: /etc/shadow
        follow: false
        owner: '{{ file_owner_etc_shadow_newown }}'
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on Backup group File [ref]
To properly set the permissions of `/etc/group-`, run the command:
    $ sudo chmod 0644 /etc/group-
Rationale: | The `/etc/group-` file is a backup file of `/etc/group`, and as such, it contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_backup_etc_group
References: |
nist | AC-6 (1)
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.1.5
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    chmod u-xs,g-xws,o-xwt /etc/group-
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Test for existence /etc/group-
      ansible.builtin.stat:
        path: /etc/group-
      register: file_exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_backup_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xws,o-xwt on /etc/group-
      ansible.builtin.file:
        path: /etc/group-
        mode: u-xs,g-xws,o-xwt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_backup_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on Backup gshadow File [ref]
To properly set the permissions of `/etc/gshadow-`, run the command:
    $ sudo chmod 0000 /etc/gshadow-
Rationale: | The `/etc/gshadow-` file is a backup of `/etc/gshadow`, and as such, it contains group password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_backup_etc_gshadow
References: |
nist | AC-6 (1)
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.1.9
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    chmod u-xwrs,g-xwrs,o-xwrt /etc/gshadow-
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Test for existence /etc/gshadow-
      ansible.builtin.stat:
        path: /etc/gshadow-
      register: file_exists
      tags:
      - NIST-800-53-AC-6 (1)
      - configure_strategy
      - file_permissions_backup_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/gshadow-
      ansible.builtin.file:
        path: /etc/gshadow-
        mode: u-xwrs,g-xwrs,o-xwrt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6 (1)
      - configure_strategy
      - file_permissions_backup_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on Backup passwd File [ref]
To properly set the permissions of `/etc/passwd-`, run the command:
    $ sudo chmod 0644 /etc/passwd-
Rationale: | The `/etc/passwd-` file is a backup file of `/etc/passwd`, and as such, it contains information about the users that are configured on the system. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_backup_etc_passwd
References: |
nist | AC-6 (1)
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.1.3
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    chmod u-xs,g-xws,o-xwt /etc/passwd-
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Test for existence /etc/passwd-
      ansible.builtin.stat:
        path: /etc/passwd-
      register: file_exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_backup_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xws,o-xwt on /etc/passwd-
      ansible.builtin.file:
        path: /etc/passwd-
        mode: u-xs,g-xws,o-xwt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_backup_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on Backup shadow File [ref]
To properly set the permissions of `/etc/shadow-`, run the command:
    $ sudo chmod 0000 /etc/shadow-
Rationale: | The `/etc/shadow-` file is a backup file of `/etc/shadow`, and as such, it contains the list of local system accounts and password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_backup_etc_shadow
References: |
nist | AC-6 (1)
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
cis | 6.1.7
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    chmod u-xwrs,g-xwrs,o-xwrt /etc/shadow-
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Test for existence /etc/shadow-
      ansible.builtin.stat:
        path: /etc/shadow-
      register: file_exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_backup_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/shadow-
      ansible.builtin.file:
        path: /etc/shadow-
        mode: u-xwrs,g-xwrs,o-xwrt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6 (1)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_backup_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on group File [ref]
To properly set the permissions of `/etc/group`, run the command:
    $ sudo chmod 0644 /etc/group
Rationale: | The `/etc/group` file contains information regarding groups that are configured on the system. Protection of this file is important for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_etc_group
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.1.4
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    chmod u-xs,g-xws,o-xwt /etc/group
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Test for existence /etc/group
      ansible.builtin.stat:
        path: /etc/group
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xws,o-xwt on /etc/group
      ansible.builtin.file:
        path: /etc/group
        mode: u-xs,g-xws,o-xwt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_etc_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on gshadow File [ref]
To properly set the permissions of `/etc/gshadow`, run the command:
    $ sudo chmod 0000 /etc/gshadow
Rationale: | The `/etc/gshadow` file contains group password hashes. Protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_etc_gshadow
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.1.8
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    chmod u-xwrs,g-xwrs,o-xwrt /etc/gshadow
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Test for existence /etc/gshadow
      ansible.builtin.stat:
        path: /etc/gshadow
      register: file_exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_permissions_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/gshadow
      ansible.builtin.file:
        path: /etc/gshadow
        mode: u-xwrs,g-xwrs,o-xwrt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_permissions_etc_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on passwd File [ref]
To properly set the permissions of `/etc/passwd`, run the command:
    $ sudo chmod 0644 /etc/passwd
Rationale: | If the `/etc/passwd` file is writable by a group-owner or the world the risk of its compromise is increased. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_etc_passwd
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.1.1, 6.1.2
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    chmod u-xs,g-xws,o-xwt /etc/passwd
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Test for existence /etc/passwd
      ansible.builtin.stat:
        path: /etc/passwd
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xws,o-xwt on /etc/passwd
      ansible.builtin.file:
        path: /etc/passwd
        mode: u-xs,g-xws,o-xwt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_etc_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on shadow File [ref]
To properly set the permissions of `/etc/shadow`, run the command:
    $ sudo chmod 0000 /etc/shadow
Rationale: | The `/etc/shadow` file contains the list of local system accounts and stores password hashes. Protection of this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information which could weaken the system security posture.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_etc_shadow
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.2.2
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-8.7.c
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 6.1.6
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    chmod u-xwrs,g-xwrs,o-xwrt /etc/shadow
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Test for existence /etc/shadow
      ansible.builtin.stat:
        path: /etc/shadow
      register: file_exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xwrs,g-xwrs,o-xwrt on /etc/shadow
      ansible.builtin.file:
        path: /etc/shadow
        mode: u-xwrs,g-xwrs,o-xwrt
      when: file_exists.stat is defined and file_exists.stat.exists
      tags:
      - CJIS-5.5.2.2
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-8.7.c
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_etc_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify that All World-Writable Directories Have Sticky Bits Set [ref]
When the so-called 'sticky bit' is set on a directory, only the owner of a given file may remove that file from the directory. Without the sticky bit, any user with write access to a directory may remove any file in the directory. Setting the sticky bit prevents users from removing each other's files. In cases where there is no reason for a directory to be world-writable, a better solution is to remove that permission rather than to set the sticky bit. However, if a directory is used by a particular application, consult that application's documentation instead of blindly changing modes. To set the sticky bit on a world-writable directory DIR, run the following command:
    $ sudo chmod +t DIR
Warning: This rule can take a long time to perform the check and might consume a considerable amount of resources depending on the number of directories present on the system. It is not a problem in most cases, but especially systems with a large number of directories can be affected. See `https://access.redhat.com/articles/6999111`. Warning: Please note that there might be cases where the rule remediation cannot fix directory permissions. This can happen for example when running on a system with some immutable parts. These immutable parts cannot be remediated because they are read-only. Example of such directories can be OStree deployments located at `/sysroot/ostree/deploy`. In such case, it is needed to make modifications to the underlying ostree snapshot and this is out of scope of regular rule remediation.
Rationale: | Failing to set the sticky bit on public directories allows unauthorized users to delete files in the directory structure. The only authorized public directories are those temporary directories supplied with the system, or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system, by users for temporary file storage (such as `/tmp`), and for directories requiring global read/write access.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_dir_perms_world_writable_sticky_bits
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000138-GPOS-00069
anssi | R54
cis | 6.1.11
ism | 1409
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
    df --local -P | awk '{if (NR!=1) print $6}' \
    | xargs -I '$6' find '$6' -xdev -type d \
    \( -perm -0002 -a ! -perm -1000 \) 2>/dev/null \
    -exec chmod a+t {} +
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Verify that All World-Writable Directories Have Sticky Bits Set - Define Excluded
        (Non-Local) File Systems and Paths
      ansible.builtin.set_fact:
        excluded_fstypes:
        - afs
        - autofs
        - ceph
        - cifs
        - smb3
        - smbfs
        - sshfs
        - ncpfs
        - ncp
        - nfs
        - nfs4
        - gfs
        - gfs2
        - glusterfs
        - gpfs
        - pvfs2
        - ocfs2
        - lustre
        - davfs
        - fuse.sshfs
        excluded_paths:
        - dev
        - proc
        - run
        - sys
        search_paths: []
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - dir_perms_world_writable_sticky_bits
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Verify that All World-Writable Directories Have Sticky Bits Set - Find Relevant
        Root Directories Ignoring Pre-Defined Excluded Paths
      ansible.builtin.find:
        paths: /
        file_type: directory
        excludes: '{{ excluded_paths }}'
        hidden: true
        recurse: false
      register: result_relevant_root_dirs
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - dir_perms_world_writable_sticky_bits
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Verify that All World-Writable Directories Have Sticky Bits Set - Include
        Relevant Root Directories in a List of Paths to be Searched
      ansible.builtin.set_fact:
        search_paths: '{{ search_paths | union([item.path]) }}'
      loop: '{{ result_relevant_root_dirs.files }}'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - dir_perms_world_writable_sticky_bits
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Verify that All World-Writable Directories Have Sticky Bits Set - Increment
        Search Paths List with Local Partitions Mount Points
      ansible.builtin.set_fact:
        search_paths: '{{ search_paths | union([item.mount]) }}'
      loop: '{{ ansible_mounts }}'
      when:
      - item.fstype not in excluded_fstypes
      - item.mount != '/'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - dir_perms_world_writable_sticky_bits
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Verify that All World-Writable Directories Have Sticky Bits Set - Increment
        Search Paths List with Local NFS File System Targets
      ansible.builtin.set_fact:
        search_paths: '{{ search_paths | union([item.device.split('':'')[1]]) }}'
      loop: '{{ ansible_mounts }}'
      when: item.device is search("localhost:")
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - dir_perms_world_writable_sticky_bits
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Verify that All World-Writable Directories Have Sticky Bits Set - Define Rule
        Specific Facts
      ansible.builtin.set_fact:
        world_writable_dirs: []
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - dir_perms_world_writable_sticky_bits
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Verify that All World-Writable Directories Have Sticky Bits Set - Find All
        Uncompliant Directories in Local File Systems
      ansible.builtin.command:
        cmd: find {{ item }} -xdev -type d ( -perm -0002 -a ! -perm -1000 )
      loop: '{{ search_paths }}'
      changed_when: false
      register: result_found_dirs
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - dir_perms_world_writable_sticky_bits
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Verify that All World-Writable Directories Have Sticky Bits Set - Create List
        of World Writable Directories Without Sticky Bit
      ansible.builtin.set_fact:
        world_writable_dirs: '{{ world_writable_dirs | union(item.stdout_lines) | list
          }}'
      loop: '{{ result_found_dirs.results }}'
      when: result_found_dirs is not skipped and item is not skipped
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - dir_perms_world_writable_sticky_bits
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Verify that All World-Writable Directories Have Sticky Bits Set - Ensure Sticky
        Bit is Set on Local World Writable Directories
      ansible.builtin.file:
        path: '{{ item }}'
        mode: a+t
      loop: '{{ world_writable_dirs }}'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - dir_perms_world_writable_sticky_bits
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure No World-Writable Files Exist [ref]
It is generally a good idea to remove global (other) write access to a file when it is discovered. However, check with documentation for specific applications before making changes. Also, monitor for recurring world-writable files, as these may be symptoms of a misconfigured application or user account. Finally, this applies to real files and not virtual files that are a part of pseudo file systems such as `sysfs` or `procfs`. Warning: This rule can take a long time to perform the check and might consume a considerable amount of resources depending on the number of files present on the system. It is not a problem in most cases, but especially systems with a large number of files can be affected. See `https://access.redhat.com/articles/6999111`.
Rationale: | Data in world-writable files can be modified by any user on the system. In almost all circumstances, files can be configured using a combination of user and group permissions to support whatever legitimate access is needed without the risk caused by world-writable files.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_unauthorized_world_writable
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
anssi | R54
cis | 6.1.11
ism | 1409
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    FILTER_NODEV=$(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)

    # Do not consider /sysroot partition because it contains only the physical
    # read-only root on bootable containers.
    PARTITIONS=$(findmnt -n -l -k -it $FILTER_NODEV | awk '{ print $1 }' | grep -v "/sysroot")

    for PARTITION in $PARTITIONS; do
      find "${PARTITION}" -xdev -type f -perm -002 -exec chmod o-w {} \; 2>/dev/null
    done

    # Ensure /tmp is also fixed when tmpfs is used.
    if grep "^tmpfs /tmp" /proc/mounts; then
      find /tmp -xdev -type f -perm -002 -exec chmod o-w {} \; 2>/dev/null
    fi
#### Rule Ensure All Files Are Owned by a Group [ref]
If any file is not group-owned by a valid defined group, the cause of the lack of group-ownership must be investigated. Following this, those files should be deleted or assigned to an appropriate group. The groups need to be defined in `/etc/group` or in `/usr/lib/group` if `nss-altfiles` are configured to be used in `/etc/nsswitch.conf`. Locate the mount points related to local devices by the following command:
    $ findmnt -n -l -k -it $(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)
For all mount points listed by the previous command, it is necessary to search for files which do not belong to a valid group using the following command:
    $ sudo find MOUNTPOINT -xdev -nogroup 2>/dev/null
Warning: This rule only considers local groups as valid groups. If you have your groups defined outside `/etc/group` or `/usr/lib/group`, the rule won't consider those. Warning: This rule can take a long time to perform the check and might consume a considerable amount of resources depending on the number of files present on the system. It is not a problem in most cases, but especially systems with a large number of files can be affected. See `https://access.redhat.com/articles/6999111`.
Rationale: | Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account, or other similar cases. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_ungroupowned
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.06, DSS06.10
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, PR.PT-3
os-srg | SRG-OS-000480-GPOS-00227
anssi | R53
cis | 6.1.12
pcidss4 | 2.2.6, 2.2
#### Rule Ensure All Files Are Owned by a User [ref]
If any files are not owned by a user, then the cause of their lack of ownership should be investigated. Following this, the files should be deleted or assigned to an appropriate user. Locate the mount points related to local devices by the following command:
    $ findmnt -n -l -k -it $(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)
For all mount points listed by the previous command, it is necessary to search for files which do not belong to a valid user using the following command:
    $ sudo find MOUNTPOINT -xdev -nouser 2>/dev/null
Warning: For this rule to evaluate centralized user accounts, `getent` must be working properly so that running the command
    getent passwd
returns a list of all users in your organization. If using the System Security Services Daemon (SSSD),
    enumerate = true
must be configured in your organization's domain to return a complete list of users Warning: This rule can take a long time to perform the check and might consume a considerable amount of resources depending on the number of files present on the system. It is not a problem in most cases, but especially systems with a large number of files can be affected. See `https://access.redhat.com/articles/6999111`.
Rationale: | Unowned files do not directly imply a security problem, but they are generally a sign that something is amiss. They may be caused by an intruder, by incorrect software installation or draft software removal, or by failure to remove all files belonging to a deleted account, or other similar cases. The files should be repaired so they will not cause problems when accounts are created in the future, and the cause should be discovered and addressed.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_no_files_unowned_by_user
References: |
cis-csc | 11, 12, 13, 14, 15, 16, 18, 3, 5, 9
cobit5 | APO01.06, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.AC-6, PR.DS-5, PR.IP-1, PR.PT-3
os-srg | SRG-OS-000480-GPOS-00227
anssi | R53
cis | 6.1.12
pcidss4 | 2.2.6, 2.2
Group Restrict Dynamic Mounting and Unmounting of Filesystems Group contains 8 rules
[ref] Linux includes a number of facilities for the automated addition and removal of filesystems on a running system. These facilities may be necessary in many environments, but this capability also carries some risk -- whether direct risk from allowing users to introduce arbitrary filesystems, or risk that software flaws in the automated mount facility itself could allow an attacker to compromise the system. This command can be used to list the types of filesystems that are available to the currently executing kernel:
    $ find /lib/modules/`uname -r`/kernel/fs -type f -name '*.ko'
If these filesystems are not required then they can be explicitly disabled in a configuratio file in `/etc/modprobe.d`.
#### Rule Disable Mounting of cramfs [ref]
To configure the system to prevent the `cramfs` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/cramfs.conf`:
    install cramfs /bin/false
This entry will cause a non-zero return value during a `cramfs` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):
    install cramfs /bin/true
This effectively prevents usage of this uncommon filesystem. The `cramfs` filesystem type is a compressed read-only Linux filesystem embedded in small footprint systems. A `cramfs` image can be used without having to first decompress the image.
Rationale: | Removing support for unneeded filesystem types reduces the local attack surface of the server.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_cramfs_disabled
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.4.6
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
os-srg | SRG-OS-000095-GPOS-00049
cis | 1.1.1.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if LC_ALL=C grep -q -m 1 "^install cramfs" /etc/modprobe.d/cramfs.conf ; then

    	sed -i 's#^install cramfs.*#install cramfs /bin/false#g' /etc/modprobe.d/cramfs.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/cramfs.conf
    	echo "install cramfs /bin/false" >> /etc/modprobe.d/cramfs.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_cramfs_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required

    - name: Ensure kernel module 'cramfs' is disabled
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/modprobe.d/cramfs.conf
        regexp: install\s+cramfs
        line: install cramfs /bin/false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_cramfs_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required
#### Rule Disable Mounting of freevxfs [ref]
To configure the system to prevent the `freevxfs` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/freevxfs.conf`:
    install freevxfs /bin/false
This entry will cause a non-zero return value during a `freevxfs` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):
    install freevxfs /bin/true
This effectively prevents usage of this uncommon filesystem.
Rationale: | Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_freevxfs_disabled
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.4.6
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 1.1.1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if LC_ALL=C grep -q -m 1 "^install freevxfs" /etc/modprobe.d/freevxfs.conf ; then

    	sed -i 's#^install freevxfs.*#install freevxfs /bin/false#g' /etc/modprobe.d/freevxfs.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/freevxfs.conf
    	echo "install freevxfs /bin/false" >> /etc/modprobe.d/freevxfs.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_freevxfs_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required

    - name: Ensure kernel module 'freevxfs' is disabled
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/modprobe.d/freevxfs.conf
        regexp: install\s+freevxfs
        line: install freevxfs /bin/false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_freevxfs_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required
#### Rule Disable Mounting of hfs [ref]
To configure the system to prevent the `hfs` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/hfs.conf`:
    install hfs /bin/false
This entry will cause a non-zero return value during a `hfs` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):
    install hfs /bin/true
This effectively prevents usage of this uncommon filesystem.
Rationale: | Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_hfs_disabled
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.4.6
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 1.1.1.6
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if LC_ALL=C grep -q -m 1 "^install hfs" /etc/modprobe.d/hfs.conf ; then

    	sed -i 's#^install hfs.*#install hfs /bin/false#g' /etc/modprobe.d/hfs.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/hfs.conf
    	echo "install hfs /bin/false" >> /etc/modprobe.d/hfs.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_hfs_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required

    - name: Ensure kernel module 'hfs' is disabled
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/modprobe.d/hfs.conf
        regexp: install\s+hfs
        line: install hfs /bin/false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_hfs_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required
#### Rule Disable Mounting of hfsplus [ref]
To configure the system to prevent the `hfsplus` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/hfsplus.conf`:
    install hfsplus /bin/false
This entry will cause a non-zero return value during a `hfsplus` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):
    install hfsplus /bin/true
This effectively prevents usage of this uncommon filesystem.
Rationale: | Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_hfsplus_disabled
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.4.6
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 1.1.1.7
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if LC_ALL=C grep -q -m 1 "^install hfsplus" /etc/modprobe.d/hfsplus.conf ; then

    	sed -i 's#^install hfsplus.*#install hfsplus /bin/false#g' /etc/modprobe.d/hfsplus.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/hfsplus.conf
    	echo "install hfsplus /bin/false" >> /etc/modprobe.d/hfsplus.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_hfsplus_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required

    - name: Ensure kernel module 'hfsplus' is disabled
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/modprobe.d/hfsplus.conf
        regexp: install\s+hfsplus
        line: install hfsplus /bin/false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_hfsplus_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required
#### Rule Disable Mounting of jffs2 [ref]
To configure the system to prevent the `jffs2` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/jffs2.conf`:
    install jffs2 /bin/false
This entry will cause a non-zero return value during a `jffs2` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):
    install jffs2 /bin/true
This effectively prevents usage of this uncommon filesystem.
Rationale: | Linux kernel modules which implement filesystems that are not needed by the local system should be disabled.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_jffs2_disabled
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.4.6
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 1.1.1.5
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if LC_ALL=C grep -q -m 1 "^install jffs2" /etc/modprobe.d/jffs2.conf ; then

    	sed -i 's#^install jffs2.*#install jffs2 /bin/false#g' /etc/modprobe.d/jffs2.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/jffs2.conf
    	echo "install jffs2 /bin/false" >> /etc/modprobe.d/jffs2.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_jffs2_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required

    - name: Ensure kernel module 'jffs2' is disabled
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/modprobe.d/jffs2.conf
        regexp: install\s+jffs2
        line: install jffs2 /bin/false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_jffs2_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required
#### Rule Disable Mounting of squashfs [ref]
To configure the system to prevent the `squashfs` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/squashfs.conf`:
    install squashfs /bin/false
This entry will cause a non-zero return value during a `squashfs` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):
    install squashfs /bin/true
This effectively prevents usage of this uncommon filesystem. The `squashfs` filesystem type is a compressed read-only Linux filesystem embedded in small footprint systems (similar to `cramfs`). A `squashfs` image can be used without having to first decompress the image.
Rationale: | Removing support for unneeded filesystem types reduces the local attack surface of the system.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_squashfs_disabled
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.4.6
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 1.1.1.1
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if LC_ALL=C grep -q -m 1 "^install squashfs" /etc/modprobe.d/squashfs.conf ; then

    	sed -i 's#^install squashfs.*#install squashfs /bin/false#g' /etc/modprobe.d/squashfs.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/squashfs.conf
    	echo "install squashfs /bin/false" >> /etc/modprobe.d/squashfs.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_squashfs_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required

    - name: Ensure kernel module 'squashfs' is disabled
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/modprobe.d/squashfs.conf
        regexp: install\s+squashfs
        line: install squashfs /bin/false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_squashfs_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required
#### Rule Disable Mounting of udf [ref]
To configure the system to prevent the `udf` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/udf.conf`:
    install udf /bin/false
This entry will cause a non-zero return value during a `udf` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):
    install udf /bin/true
This effectively prevents usage of this uncommon filesystem. The `udf` filesystem type is the universal disk format used to implement the ISO/IEC 13346 and ECMA-167 specifications. This is an open vendor filesystem type for data storage on a broad range of media. This filesystem type is necessary to support writing DVDs and newer optical disc formats.
Rationale: | Removing support for unneeded filesystem types reduces the local attack surface of the system.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_udf_disabled
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
cui | 3.4.6
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 1.1.1.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if LC_ALL=C grep -q -m 1 "^install udf" /etc/modprobe.d/udf.conf ; then

    	sed -i 's#^install udf.*#install udf /bin/false#g' /etc/modprobe.d/udf.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/udf.conf
    	echo "install udf /bin/false" >> /etc/modprobe.d/udf.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_udf_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required

    - name: Ensure kernel module 'udf' is disabled
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/modprobe.d/udf.conf
        regexp: install\s+udf
        line: install udf /bin/false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.4.6
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - kernel_module_udf_disabled
      - low_complexity
      - low_severity
      - medium_disruption
      - reboot_required
#### Rule Disable Modprobe Loading of USB Storage Driver [ref]
To prevent USB storage devices from being used, configure the kernel module loading system to prevent automatic loading of the USB storage driver. To configure the system to prevent the `usb-storage` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/usb-storage.conf`:
    install usb-storage /bin/false
This entry will cause a non-zero return value during a `usb-storage` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):
    install usb-storage /bin/true
This will prevent the `modprobe` program from loading the `usb-storage` module, but will not prevent an administrator (or another program) from using the `insmod` program to load the module manually.
Rationale: | USB storage devices such as thumb drives can be used to introduce malicious software.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_kernel_module_usb-storage_disabled
References: |
cis-csc | 1, 12, 15, 16, 5
cobit5 | APO13.01, DSS01.04, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.1.21
hipaa | 164.308(a)(3)(i), 164.308(a)(3)(ii)(A), 164.310(d)(1), 164.310(d)(2), 164.312(a)(1), 164.312(a)(2)(iv), 164.312(b)
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.6
iso27001-2013 | A.11.2.6, A.13.1.1, A.13.2.1, A.18.1.4, A.6.2.1, A.6.2.2, A.7.1.1, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.2, A.9.4.3
nist | CM-7(a), CM-7(b), CM-6(a), MP-7
nist-csf | PR.AC-1, PR.AC-3, PR.AC-6, PR.AC-7
os-srg | SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000480-GPOS-00227
app-srg-ctr | SRG-APP-000141-CTR-000315
cis | 1.1.9
pcidss4 | 3.4.2, 3.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if LC_ALL=C grep -q -m 1 "^install usb-storage" /etc/modprobe.d/usb-storage.conf ; then

    	sed -i 's#^install usb-storage.*#install usb-storage /bin/false#g' /etc/modprobe.d/usb-storage.conf
    else
    	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/usb-storage.conf
    	echo "install usb-storage /bin/false" >> /etc/modprobe.d/usb-storage.conf
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.21
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - PCI-DSSv4-3.4
      - PCI-DSSv4-3.4.2
      - disable_strategy
      - kernel_module_usb-storage_disabled
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required

    - name: Ensure kernel module 'usb-storage' is disabled
      ansible.builtin.lineinfile:
        create: true
        dest: /etc/modprobe.d/usb-storage.conf
        regexp: install\s+usb-storage
        line: install usb-storage /bin/false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.21
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - PCI-DSSv4-3.4
      - PCI-DSSv4-3.4.2
      - disable_strategy
      - kernel_module_usb-storage_disabled
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
Group Restrict Partition Mount Options Group contains 19 rules
[ref] System partitions can be mounted with certain options that limit what files on those partitions can do. These options are set in the `/etc/fstab` configuration file, and can be used to make certain types of malicious behavior more difficult.
#### Rule Add nodev Option to /dev/shm [ref]
The `nodev` mount option can be used to prevent creation of device files in `/dev/shm`. Legitimate character and block devices should not exist within temporary directories like `/dev/shm`. Add the `nodev` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/dev/shm`.
Rationale: | The only legitimate location for device files is the `/dev` directory located on the root partition. The only exception to this is chroot jails.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_dev_shm_nodev
References: |
cis-csc | 11, 13, 14, 3, 8, 9
cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
os-srg | SRG-OS-000368-GPOS-00154
cis | 1.1.8.2
ism | 1409
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); then

    function perform_remediation {

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /dev/shm)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type="tmpfs"
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo "tmpfs /dev/shm tmpfs defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
        fi

        if mkdir -p "/dev/shm"; then
            if mountpoint -q "/dev/shm"; then
                mount -o remount --target "/dev/shm"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /dev/shm: Check information associated to mountpoint'
      ansible.builtin.command: findmnt  '/dev/shm'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when: ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /dev/shm: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /dev/shm: If /dev/shm not mounted, craft mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /dev/shm
        - tmpfs
        - tmpfs
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - ("" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /dev/shm: Make sure nodev option is part of the to /dev/shm
        options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nodev''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - mount_info is defined and "nodev" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /dev/shm: Ensure /dev/shm is mounted with nodev option'
      ansible.posix.mount:
        path: /dev/shm
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("" |
        length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_nodev
      - no_reboot_needed
#### Rule Add noexec Option to /dev/shm [ref]
The `noexec` mount option can be used to prevent binaries from being executed out of `/dev/shm`. It can be dangerous to allow the execution of binaries from world-writable temporary storage directories such as `/dev/shm`. Add the `noexec` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/dev/shm`.
Rationale: | Allowing users to execute binaries from world-writable directories such as `/dev/shm` can expose the system to potential compromise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_dev_shm_noexec
References: |
cis-csc | 11, 13, 14, 3, 8, 9
cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
os-srg | SRG-OS-000368-GPOS-00154
cis | 1.1.8.3
ism | 1409
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); then

    function perform_remediation {

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /dev/shm)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type="tmpfs"
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo "tmpfs /dev/shm tmpfs defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "noexec"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
        fi

        if mkdir -p "/dev/shm"; then
            if mountpoint -q "/dev/shm"; then
                mount -o remount --target "/dev/shm"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /dev/shm: Check information associated to mountpoint'
      ansible.builtin.command: findmnt  '/dev/shm'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when: ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /dev/shm: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /dev/shm: If /dev/shm not mounted, craft mount_info
        manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /dev/shm
        - tmpfs
        - tmpfs
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - ("" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /dev/shm: Make sure noexec option is part of the to
        /dev/shm options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''noexec''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - mount_info is defined and "noexec" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /dev/shm: Ensure /dev/shm is mounted with noexec option'
      ansible.posix.mount:
        path: /dev/shm
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("" |
        length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_noexec
      - no_reboot_needed
#### Rule Add nosuid Option to /dev/shm [ref]
The `nosuid` mount option can be used to prevent execution of setuid programs in `/dev/shm`. The SUID and SGID permissions should not be required in these world-writable directories. Add the `nosuid` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/dev/shm`.
Rationale: | The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_dev_shm_nosuid
References: |
cis-csc | 11, 13, 14, 3, 8, 9
cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
os-srg | SRG-OS-000368-GPOS-00154
cis | 1.1.8.4
ism | 1409
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ); then

    function perform_remediation {

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /dev/shm)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type="tmpfs"
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo "tmpfs /dev/shm tmpfs defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
        fi

        if mkdir -p "/dev/shm"; then
            if mountpoint -q "/dev/shm"; then
                mount -o remount --target "/dev/shm"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /dev/shm: Check information associated to mountpoint'
      ansible.builtin.command: findmnt  '/dev/shm'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when: ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /dev/shm: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /dev/shm: If /dev/shm not mounted, craft mount_info
        manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /dev/shm
        - tmpfs
        - tmpfs
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - ("" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /dev/shm: Make sure nosuid option is part of the to
        /dev/shm options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nosuid''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - mount_info is defined and "nosuid" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /dev/shm: Ensure /dev/shm is mounted with nosuid option'
      ansible.posix.mount:
        path: /dev/shm
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("" |
        length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_dev_shm_nosuid
      - no_reboot_needed
#### Rule Add nodev Option to /home [ref]
The `nodev` mount option can be used to prevent device files from being created in `/home`. Legitimate character and block devices should exist only in the `/dev` directory on the root partition or within chroot jails built for system services. Add the `nodev` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/home`.
Rationale: | The only legitimate location for device files is the `/dev` directory located on the root partition. The only exception to this is chroot jails.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_home_nodev
References: |
os-srg | SRG-OS-000368-GPOS-00154
cis | 1.1.7.2
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/home" > /dev/null || findmnt --fstab "/home" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /home has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/home")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/home' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /home in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /home)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /home  defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
        fi

        if mkdir -p "/home"; then
            if mountpoint -q "/home"; then
                mount -o remount --target "/home"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /home --mountoptions="nodev"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - mount_option_home_nodev
      - no_reboot_needed
      - unknown_severity

    - name: 'Add nodev Option to /home: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/home'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/home" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - mount_option_home_nodev
      - no_reboot_needed
      - unknown_severity

    - name: 'Add nodev Option to /home: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/home" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - mount_option_home_nodev
      - no_reboot_needed
      - unknown_severity

    - name: 'Add nodev Option to /home: If /home not mounted, craft mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /home
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/home" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - mount_option_home_nodev
      - no_reboot_needed
      - unknown_severity

    - name: 'Add nodev Option to /home: Make sure nodev option is part of the to /home
        options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nodev''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/home" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "nodev" not in (mount_info.options | default(''))
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - mount_option_home_nodev
      - no_reboot_needed
      - unknown_severity

    - name: 'Add nodev Option to /home: Ensure /home is mounted with nodev option'
      ansible.posix.mount:
        path: /home
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/home" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - mount_option_home_nodev
      - no_reboot_needed
      - unknown_severity
#### Rule Add nosuid Option to /home [ref]
The `nosuid` mount option can be used to prevent execution of setuid programs in `/home`. The SUID and SGID permissions should not be required in these user data directories. Add the `nosuid` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/home`.
Rationale: | The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from user home directory partitions.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_home_nosuid
References: |
cis-csc | 11, 13, 14, 3, 8, 9
cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
os-srg | SRG-OS-000368-GPOS-00154, SRG-OS-000480-GPOS-00227
anssi | R28
cis | 1.1.7.3
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/home" > /dev/null || findmnt --fstab "/home" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /home has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/home")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/home' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /home in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /home)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /home  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
        fi

        if mkdir -p "/home"; then
            if mountpoint -q "/home"; then
                mount -o remount --target "/home"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /home --mountoptions="nosuid"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_home_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /home: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/home'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/home" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_home_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /home: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/home" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_home_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /home: If /home not mounted, craft mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /home
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/home" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_home_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /home: Make sure nosuid option is part of the to /home
        options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nosuid''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/home" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "nosuid" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_home_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /home: Ensure /home is mounted with nosuid option'
      ansible.posix.mount:
        path: /home
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/home" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_home_nosuid
      - no_reboot_needed
#### Rule Add nodev Option to /tmp [ref]
The `nodev` mount option can be used to prevent device files from being created in `/tmp`. Legitimate character and block devices should not exist within temporary directories like `/tmp`. Add the `nodev` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/tmp`.
Rationale: | The only legitimate location for device files is the `/dev` directory located on the root partition. The only exception to this is chroot jails.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_tmp_nodev
References: |
cis-csc | 11, 13, 14, 3, 8, 9
cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
os-srg | SRG-OS-000368-GPOS-00154
cis | 1.1.2.2
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/tmp" > /dev/null || findmnt --fstab "/tmp" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /tmp has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/tmp")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /tmp in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /tmp)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /tmp  defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
        fi

        if mkdir -p "/tmp"; then
            if mountpoint -q "/tmp"; then
                mount -o remount --target "/tmp"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /tmp --mountoptions="nodev"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /tmp: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/tmp'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /tmp: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /tmp: If /tmp not mounted, craft mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /tmp
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /tmp: Make sure nodev option is part of the to /tmp options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nodev''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "nodev" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /tmp: Ensure /tmp is mounted with nodev option'
      ansible.posix.mount:
        path: /tmp
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_nodev
      - no_reboot_needed
#### Rule Add noexec Option to /tmp [ref]
The `noexec` mount option can be used to prevent binaries from being executed out of `/tmp`. Add the `noexec` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/tmp`.
Rationale: | Allowing users to execute binaries from world-writable directories such as `/tmp` should never be necessary in normal operation and can expose the system to potential compromise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_tmp_noexec
References: |
cis-csc | 11, 13, 14, 3, 8, 9
cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
os-srg | SRG-OS-000368-GPOS-00154
anssi | R28
cis | 1.1.2.3
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/tmp" > /dev/null || findmnt --fstab "/tmp" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /tmp has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/tmp")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /tmp in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /tmp)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /tmp  defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "noexec"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
        fi

        if mkdir -p "/tmp"; then
            if mountpoint -q "/tmp"; then
                mount -o remount --target "/tmp"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /tmp --mountoptions="noexec"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /tmp: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/tmp'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /tmp: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /tmp: If /tmp not mounted, craft mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /tmp
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /tmp: Make sure noexec option is part of the to /tmp
        options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''noexec''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "noexec" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /tmp: Ensure /tmp is mounted with noexec option'
      ansible.posix.mount:
        path: /tmp
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_noexec
      - no_reboot_needed
#### Rule Add nosuid Option to /tmp [ref]
The `nosuid` mount option can be used to prevent execution of setuid programs in `/tmp`. The SUID and SGID permissions should not be required in these world-writable directories. Add the `nosuid` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/tmp`.
Rationale: | The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_tmp_nosuid
References: |
cis-csc | 11, 13, 14, 3, 8, 9
cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS05.06, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.11.2.9, A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.8.2.1, A.8.2.2, A.8.2.3, A.8.3.1, A.8.3.3, A.9.1.2
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
os-srg | SRG-OS-000368-GPOS-00154
anssi | R28
cis | 1.1.2.4
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/tmp" > /dev/null || findmnt --fstab "/tmp" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /tmp has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/tmp")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /tmp in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /tmp)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /tmp  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
        fi

        if mkdir -p "/tmp"; then
            if mountpoint -q "/tmp"; then
                mount -o remount --target "/tmp"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /tmp --mountoptions="nosuid"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /tmp: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/tmp'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /tmp: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /tmp: If /tmp not mounted, craft mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /tmp
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /tmp: Make sure nosuid option is part of the to /tmp
        options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nosuid''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "nosuid" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /tmp: Ensure /tmp is mounted with nosuid option'
      ansible.posix.mount:
        path: /tmp
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/tmp" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_tmp_nosuid
      - no_reboot_needed
#### Rule Add nodev Option to /var/log/audit [ref]
The `nodev` mount option can be used to prevent device files from being created in `/var/log/audit`. Legitimate character and block devices should exist only in the `/dev` directory on the root partition or within chroot jails built for system services. Add the `nodev` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/var/log/audit`.
Rationale: | The only legitimate location for device files is the `/dev` directory located on the root partition. The only exception to this is chroot jails.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_log_audit_nodev
References: |
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
ospp | FMT_SMF_EXT.1
os-srg | SRG-OS-000368-GPOS-00154
cis | 1.1.6.3
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/var/log/audit" > /dev/null || findmnt --fstab "/var/log/audit" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /var/log/audit has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/log/audit")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/var/log/audit' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /var/log/audit in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/log/audit)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /var/log/audit  defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
        fi

        if mkdir -p "/var/log/audit"; then
            if mountpoint -q "/var/log/audit"; then
                mount -o remount --target "/var/log/audit"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var/log/audit --mountoptions="nodev"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/log/audit: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/var/log/audit'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/log/audit: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/log/audit: If /var/log/audit not mounted, craft
        mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /var/log/audit
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/log/audit: Make sure nodev option is part of the
        to /var/log/audit options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nodev''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "nodev" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/log/audit: Ensure /var/log/audit is mounted with
        nodev option'
      ansible.posix.mount:
        path: /var/log/audit
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_nodev
      - no_reboot_needed
#### Rule Add noexec Option to /var/log/audit [ref]
The `noexec` mount option can be used to prevent binaries from being executed out of `/var/log/audit`. Add the `noexec` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/var/log/audit`.
Rationale: | Allowing users to execute binaries from directories containing audit log files such as `/var/log/audit` should never be necessary in normal operation and can expose the system to potential compromise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_log_audit_noexec
References: |
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
ospp | FMT_SMF_EXT.1
os-srg | SRG-OS-000368-GPOS-00154
cis | 1.1.6.2
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/var/log/audit" > /dev/null || findmnt --fstab "/var/log/audit" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /var/log/audit has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/log/audit")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/var/log/audit' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /var/log/audit in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/log/audit)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /var/log/audit  defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "noexec"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
        fi

        if mkdir -p "/var/log/audit"; then
            if mountpoint -q "/var/log/audit"; then
                mount -o remount --target "/var/log/audit"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var/log/audit --mountoptions="noexec"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/log/audit: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/var/log/audit'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/log/audit: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/log/audit: If /var/log/audit not mounted, craft
        mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /var/log/audit
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/log/audit: Make sure noexec option is part of the
        to /var/log/audit options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''noexec''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "noexec" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/log/audit: Ensure /var/log/audit is mounted with
        noexec option'
      ansible.posix.mount:
        path: /var/log/audit
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_noexec
      - no_reboot_needed
#### Rule Add nosuid Option to /var/log/audit [ref]
The `nosuid` mount option can be used to prevent execution of setuid programs in `/var/log/audit`. The SUID and SGID permissions should not be required in directories containing audit log files. Add the `nosuid` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/var/log/audit`.
Rationale: | The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from partitions designated for audit log files.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_log_audit_nosuid
References: |
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
ospp | FMT_SMF_EXT.1
os-srg | SRG-OS-000368-GPOS-00154
cis | 1.1.6.4
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/var/log/audit" > /dev/null || findmnt --fstab "/var/log/audit" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /var/log/audit has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/log/audit")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/var/log/audit' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /var/log/audit in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/log/audit)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /var/log/audit  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
        fi

        if mkdir -p "/var/log/audit"; then
            if mountpoint -q "/var/log/audit"; then
                mount -o remount --target "/var/log/audit"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var/log/audit --mountoptions="nosuid"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/log/audit: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/var/log/audit'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/log/audit: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/log/audit: If /var/log/audit not mounted, craft
        mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /var/log/audit
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/log/audit: Make sure nosuid option is part of the
        to /var/log/audit options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nosuid''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "nosuid" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/log/audit: Ensure /var/log/audit is mounted with
        nosuid option'
      ansible.posix.mount:
        path: /var/log/audit
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log/audit" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_audit_nosuid
      - no_reboot_needed
#### Rule Add nodev Option to /var/log [ref]
The `nodev` mount option can be used to prevent device files from being created in `/var/log`. Legitimate character and block devices should exist only in the `/dev` directory on the root partition or within chroot jails built for system services. Add the `nodev` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/var/log`.
Rationale: | The only legitimate location for device files is the `/dev` directory located on the root partition. The only exception to this is chroot jails.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_log_nodev
References: |
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
os-srg | SRG-OS-000368-GPOS-00154
cis | 1.1.5.2
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/var/log" > /dev/null || findmnt --fstab "/var/log" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /var/log has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/log")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/var/log' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /var/log in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/log)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /var/log  defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
        fi

        if mkdir -p "/var/log"; then
            if mountpoint -q "/var/log"; then
                mount -o remount --target "/var/log"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var/log --mountoptions="nodev"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/log: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/var/log'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/log: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/log: If /var/log not mounted, craft mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /var/log
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/log: Make sure nodev option is part of the to /var/log
        options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nodev''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "nodev" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/log: Ensure /var/log is mounted with nodev option'
      ansible.posix.mount:
        path: /var/log
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_nodev
      - no_reboot_needed
#### Rule Add noexec Option to /var/log [ref]
The `noexec` mount option can be used to prevent binaries from being executed out of `/var/log`. Add the `noexec` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/var/log`.
Rationale: | Allowing users to execute binaries from directories containing log files such as `/var/log` should never be necessary in normal operation and can expose the system to potential compromise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_log_noexec
References: |
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
os-srg | SRG-OS-000368-GPOS-00154
anssi | R28
cis | 1.1.5.3
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/var/log" > /dev/null || findmnt --fstab "/var/log" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /var/log has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/log")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/var/log' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /var/log in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/log)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /var/log  defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "noexec"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
        fi

        if mkdir -p "/var/log"; then
            if mountpoint -q "/var/log"; then
                mount -o remount --target "/var/log"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var/log --mountoptions="noexec"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/log: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/var/log'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/log: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/log: If /var/log not mounted, craft mount_info
        manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /var/log
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/log: Make sure noexec option is part of the to
        /var/log options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''noexec''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "noexec" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/log: Ensure /var/log is mounted with noexec option'
      ansible.posix.mount:
        path: /var/log
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_noexec
      - no_reboot_needed
#### Rule Add nosuid Option to /var/log [ref]
The `nosuid` mount option can be used to prevent execution of setuid programs in `/var/log`. The SUID and SGID permissions should not be required in directories containing log files. Add the `nosuid` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/var/log`.
Rationale: | The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from partitions designated for log files.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_log_nosuid
References: |
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
os-srg | SRG-OS-000368-GPOS-00154
anssi | R28
cis | 1.1.5.4
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/var/log" > /dev/null || findmnt --fstab "/var/log" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /var/log has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/log")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/var/log' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /var/log in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/log)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /var/log  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
        fi

        if mkdir -p "/var/log"; then
            if mountpoint -q "/var/log"; then
                mount -o remount --target "/var/log"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var/log --mountoptions="nosuid"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/log: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/var/log'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/log: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/log: If /var/log not mounted, craft mount_info
        manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /var/log
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/log: Make sure nosuid option is part of the to
        /var/log options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nosuid''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "nosuid" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/log: Ensure /var/log is mounted with nosuid option'
      ansible.posix.mount:
        path: /var/log
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/log" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_log_nosuid
      - no_reboot_needed
#### Rule Add nodev Option to /var [ref]
The `nodev` mount option can be used to prevent device files from being created in `/var`. Legitimate character and block devices should exist only in the `/dev` directory on the root partition or within chroot jails built for system services. Add the `nodev` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/var`.
Rationale: | The only legitimate location for device files is the `/dev` directory located on the root partition. The only exception to this is chroot jails.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_nodev
References: |
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-6, AC-6(1), MP-7
nist-csf | PR.IP-1, PR.PT-2, PR.PT-3
os-srg | SRG-OS-000368-GPOS-00154
cis | 1.1.3.2
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/var" > /dev/null || findmnt --fstab "/var" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /var has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/var' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /var in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /var  defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
        fi

        if mkdir -p "/var"; then
            if mountpoint -q "/var"; then
                mount -o remount --target "/var"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var --mountoptions="nodev"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/var'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var: If /var not mounted, craft mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /var
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var: Make sure nodev option is part of the to /var options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nodev''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "nodev" not in (mount_info.options | default(''))
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var: Ensure /var is mounted with nodev option'
      ansible.posix.mount:
        path: /var
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - NIST-800-53-AC-6
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-MP-7
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_nodev
      - no_reboot_needed
#### Rule Add nosuid Option to /var [ref]
The `nosuid` mount option can be used to prevent execution of setuid programs in `/var`. The SUID and SGID permissions should not be required for this directory. Add the `nosuid` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/var`.
Rationale: | The presence of SUID and SGID executables should be tightly controlled.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_nosuid
References: |
anssi | R28
cis | 1.1.3.3
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/var" > /dev/null || findmnt --fstab "/var" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /var has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/var' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /var in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /var  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
        fi

        if mkdir -p "/var"; then
            if mountpoint -q "/var"; then
                mount -o remount --target "/var"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var --mountoptions="nosuid"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/var'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var: If /var not mounted, craft mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /var
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var: Make sure nosuid option is part of the to /var
        options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nosuid''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "nosuid" not in (mount_info.options | default(''))
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var: Ensure /var is mounted with nosuid option'
      ansible.posix.mount:
        path: /var
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_nosuid
      - no_reboot_needed
#### Rule Add nodev Option to /var/tmp [ref]
The `nodev` mount option can be used to prevent device files from being created in `/var/tmp`. Legitimate character and block devices should not exist within temporary directories like `/var/tmp`. Add the `nodev` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/var/tmp`.
Rationale: | The only legitimate location for device files is the `/dev` directory located on the root partition. The only exception to this is chroot jails.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_tmp_nodev
References: |
os-srg | SRG-OS-000368-GPOS-00154
cis | 1.1.4.4
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/var/tmp" > /dev/null || findmnt --fstab "/var/tmp" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /var/tmp has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/tmp")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/var/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /var/tmp in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/tmp)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nodev)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /var/tmp  defaults,${previous_mount_opts}nodev 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nodev"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nodev|" /etc/fstab
        fi

        if mkdir -p "/var/tmp"; then
            if mountpoint -q "/var/tmp"; then
                mount -o remount --target "/var/tmp"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var/tmp --mountoptions="nodev"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/tmp: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/var/tmp'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/tmp: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/tmp: If /var/tmp not mounted, craft mount_info manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /var/tmp
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/tmp: Make sure nodev option is part of the to /var/tmp
        options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nodev''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "nodev" not in (mount_info.options | default(''))
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_nodev
      - no_reboot_needed

    - name: 'Add nodev Option to /var/tmp: Ensure /var/tmp is mounted with nodev option'
      ansible.posix.mount:
        path: /var/tmp
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_nodev
      - no_reboot_needed
#### Rule Add noexec Option to /var/tmp [ref]
The `noexec` mount option can be used to prevent binaries from being executed out of `/var/tmp`. Add the `noexec` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/var/tmp`.
Rationale: | Allowing users to execute binaries from world-writable directories such as `/var/tmp` should never be necessary in normal operation and can expose the system to potential compromise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_tmp_noexec
References: |
os-srg | SRG-OS-000368-GPOS-00154
anssi | R28
cis | 1.1.4.2
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/var/tmp" > /dev/null || findmnt --fstab "/var/tmp" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /var/tmp has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/tmp")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/var/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /var/tmp in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/tmp)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|noexec)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /var/tmp  defaults,${previous_mount_opts}noexec 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "noexec"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,noexec|" /etc/fstab
        fi

        if mkdir -p "/var/tmp"; then
            if mountpoint -q "/var/tmp"; then
                mount -o remount --target "/var/tmp"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var/tmp --mountoptions="noexec"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/tmp: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/var/tmp'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/tmp: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/tmp: If /var/tmp not mounted, craft mount_info
        manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /var/tmp
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/tmp: Make sure noexec option is part of the to
        /var/tmp options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''noexec''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "noexec" not in (mount_info.options | default(''))
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_noexec
      - no_reboot_needed

    - name: 'Add noexec Option to /var/tmp: Ensure /var/tmp is mounted with noexec option'
      ansible.posix.mount:
        path: /var/tmp
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_noexec
      - no_reboot_needed
#### Rule Add nosuid Option to /var/tmp [ref]
The `nosuid` mount option can be used to prevent execution of setuid programs in `/var/tmp`. The SUID and SGID permissions should not be required in these world-writable directories. Add the `nosuid` option to the fourth column of `/etc/fstab` for the line which controls mounting of `/var/tmp`.
Rationale: | The presence of SUID and SGID executables should be tightly controlled. Users should not be able to execute SUID or SGID binaries from temporary storage partitions.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_mount_option_var_tmp_nosuid
References: |
os-srg | SRG-OS-000368-GPOS-00154
anssi | R28
cis | 1.1.4.3
Remediation Shell script ⇲
Reboot: | false
    # Remediation is applicable only in certain platforms
    if ( ! ( { rpm --quiet -q kernel ;} && { rpm --quiet -q rpm-ostree ;} && { rpm --quiet -q bootc ;} && { ! rpm --quiet -q openshift-kubelet ;} && ([ -f /run/ostree-booted ] || [ -L /ostree ]) ) && ! ( [ -f /.dockerenv ] || [ -f /run/.containerenv ] ) ) && { ( findmnt --kernel "/var/tmp" > /dev/null || findmnt --fstab "/var/tmp" > /dev/null ); }; then

    function perform_remediation {

            # the mount point /var/tmp has to be defined in /etc/fstab
            # before this remediation can be executed. In case it is not defined, the
            # remediation aborts and no changes regarding the mount point are done.
            mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" "/var/tmp")"

        grep "$mount_point_match_regexp" -q /etc/fstab \
            || { echo "The mount point '/var/tmp' is not even in /etc/fstab, so we can't set up mount options" >&2;
                    echo "Not remediating, because there is no record of /var/tmp in /etc/fstab" >&2; return 1; }

        mount_point_match_regexp="$(printf "^[[:space:]]*[^#].*[[:space:]]%s[[:space:]]" /var/tmp)"

        # If the mount point is not in /etc/fstab, get previous mount options from /etc/mtab
        if ! grep -q "$mount_point_match_regexp" /etc/fstab; then
            # runtime opts without some automatic kernel/userspace-added defaults
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/mtab | head -1 |  awk '{print $4}' \
                        | sed -E "s/(rw|defaults|seclabel|nosuid)(,|$)//g;s/,$//")
            [ "$previous_mount_opts" ] && previous_mount_opts+=","
            # In iso9660 filesystems mtab could describe a "blocksize" value, this should be reflected in
            # fstab as "block".  The next variable is to satisfy shellcheck SC2050.
            fs_type=""
            if [  "$fs_type" == "iso9660" ] ; then
                previous_mount_opts=$(sed 's/blocksize=/block=/' <<< "$previous_mount_opts")
            fi
            echo " /var/tmp  defaults,${previous_mount_opts}nosuid 0 0" >> /etc/fstab
        # If the mount_opt option is not already in the mount point's /etc/fstab entry, add it
        elif ! grep "$mount_point_match_regexp" /etc/fstab | grep -q "nosuid"; then
            previous_mount_opts=$(grep "$mount_point_match_regexp" /etc/fstab | awk '{print $4}')
            sed -i "s|\(${mount_point_match_regexp}.*${previous_mount_opts}\)|\1,nosuid|" /etc/fstab
        fi

        if mkdir -p "/var/tmp"; then
            if mountpoint -q "/var/tmp"; then
                mount -o remount --target "/var/tmp"
            fi
        fi
    }

    perform_remediation

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | enable
    part /var/tmp --mountoptions="nosuid"
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | high
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/tmp: Check information associated to mountpoint'
      ansible.builtin.command: findmnt --fstab '/var/tmp'
      register: device_name
      failed_when: device_name.rc > 1
      changed_when: false
      check_mode: false
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/tmp: Create mount_info dictionary variable'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - '{{ device_name.stdout_lines[0].split() | map(''lower'') | list }}'
      - '{{ device_name.stdout_lines[1].split() | list }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length > 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/tmp: If /var/tmp not mounted, craft mount_info
        manually'
      set_fact:
        mount_info: '{{ mount_info|default({})|combine({item.0: item.1}) }}'
      with_together:
      - - target
        - source
        - fstype
        - options
      - - /var/tmp
        - ''
        - ''
        - defaults
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      - ("--fstab" | length == 0)
      - device_name.stdout is defined and device_name.stdout_lines is defined
      - (device_name.stdout | length == 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/tmp: Make sure nosuid option is part of the to
        /var/tmp options'
      set_fact:
        mount_info: '{{ mount_info | combine( {''options'':''''~(mount_info.options |
          default(''''))~('','' if (mount_info.options | default('''')) else '''')~''nosuid''
          }) }}'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined and "nosuid" not in (mount_info.options | default(''))
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_nosuid
      - no_reboot_needed

    - name: 'Add nosuid Option to /var/tmp: Ensure /var/tmp is mounted with nosuid option'
      ansible.posix.mount:
        path: /var/tmp
        src: '{{ mount_info.source | default('''') }}'
        opts: '{{ mount_info.options | default('''') }}'
        state: mounted
        fstype: '{{ mount_info.fstype | default('''') }}'
      register: mount_result
      failed_when:
      - mount_result is failed
      - '''target is busy'' not in (mount_result.msg | default(''''))'
      - '''already mounted'' not in (mount_result.msg | default(''''))'
      when:
      - ( not ( "kernel" in ansible_facts.packages and "rpm-ostree" in ansible_facts.packages
        and "bootc" in ansible_facts.packages and not "openshift-kubelet" in ansible_facts.packages
        and "ostree" in ansible_proc_cmdline ) and not ( ansible_virtualization_type in
        ["docker", "lxc", "openvz", "podman", "container"] ) )
      - '"/var/tmp" in ansible_mounts | map(attribute="mount") | list'
      - mount_info is defined
      - (device_name.stdout is defined and (device_name.stdout | length > 0)) or ("--fstab"
        | length == 0)
      tags:
      - configure_strategy
      - high_disruption
      - low_complexity
      - medium_severity
      - mount_option_var_tmp_nosuid
      - no_reboot_needed
Group Restrict Programs from Dangerous Execution Patterns Group contains 2 groups and 4 rules
[ref] The recommendations in this section are designed to ensure that the system's features to protect against potentially dangerous program execution are activated. These protections are applied at the system initialization or kernel level, and defend against certain types of badly-configured or compromised programs.
Group Disable Core Dumps Group contains 2 rules
[ref] A core dump file is the memory image of an executable program when it was terminated by the operating system due to errant behavior. In most cases, only software developers legitimately need to access these files. The core dump files may also contain sensitive information, or unnecessarily occupy large amounts of disk space. Once a hard limit is set in `/etc/security/limits.conf`, or to a file within the `/etc/security/limits.d/` directory, a user cannot increase that limit within his or her own session. If access to core dumps is required, consider restricting them to only certain users or groups. See the `limits.conf` man page for more information. The core dumps of setuid programs are further protected. The `sysctl` variable `fs.suid_dumpable` controls whether the kernel allows core dumps from these programs at all. The default value of 0 is recommended.
#### Rule Disable core dump backtraces [ref]
The `ProcessSizeMax` option in `[Coredump]` section of `/etc/systemd/coredump.conf` or in a drop-in file under `/etc/systemd/coredump.conf.d/` specifies the maximum size in bytes of a core which will be processed. Core dumps exceeding this size may be stored, but the backtrace will not be generated. Warning: If the `/etc/systemd/coredump.conf` file or a drop-in file under `/etc/systemd/coredump.conf.d/` does not already contain the `[Coredump]` section, the value will not be configured correctly.
Rationale: | A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended, however there may be overriding operational requirements to enable advanced debugging. Permitting temporary enablement of core dumps during such situations should be reviewed through local needs and policy.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_coredump_disable_backtraces
References: |
nist | CM-6
pcidss | Req-3.2
os-srg | SRG-OS-000480-GPOS-00227
cis | 1.5.4
pcidss4 | 3.3.1.1, 3.3.1, 3.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q systemd; }; then

    found=false

    # set value in all files if they contain section or key
    for f in $(echo -n "/etc/systemd/coredump.conf.d/complianceascode_hardening.conf /etc/systemd/coredump.conf.d/*.conf /etc/systemd/coredump.conf"); do
        if [ ! -e "$f" ]; then
            continue
        fi

        # find key in section and change value
        if grep -qzosP "(?m)^[[:space:]]*\[Coredump\]([^\n\[]*\n+)+?[[:space:]]*ProcessSizeMax" "$f"; then
            if ! grep -qzosP "(?m)^[[:space:]]*ProcessSizeMax[[:space:]]*=[[:space:]]*0" "$f"; then

                sed -i "/^[[:space:]]*ProcessSizeMax/s/\([[:blank:]]*=[[:blank:]]*\).*/\10/" "$f"

            fi

            found=true

        # find section and add key = value to it
        elif grep -qs "^[[:space:]]*\[Coredump\]" "$f"; then

                sed -i "/^[[:space:]]*\[Coredump\]/a ProcessSizeMax=0" "$f"

                found=true
        fi
    done

    # if section not in any file, append section with key = value to FIRST file in files parameter
    if ! $found ; then
        file=$(echo "/etc/systemd/coredump.conf.d/complianceascode_hardening.conf /etc/systemd/coredump.conf.d/*.conf /etc/systemd/coredump.conf" | cut -f1 -d ' ')
        mkdir -p "$(dirname "$file")"

        echo -e "[Coredump]\nProcessSizeMax=0" >> "$file"

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6
      - PCI-DSS-Req-3.2
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - coredump_disable_backtraces
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable core dump backtraces - Search for a section in files
      ansible.builtin.find:
        paths: '{{item.path}}'
        patterns: '{{item.pattern}}'
        contains: ^\s*\[Coredump\]
        read_whole_file: true
        use_regex: true
      register: systemd_dropin_files_with_section
      loop:
      - path: '{{ ''/etc/systemd/coredump.conf'' | dirname }}'
        pattern: '{{ ''/etc/systemd/coredump.conf'' | basename | regex_escape }}'
      - path: /etc/systemd/coredump.conf.d
        pattern: .*\.conf
      when:
      - '"kernel" in ansible_facts.packages'
      - '"systemd" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6
      - PCI-DSS-Req-3.2
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - coredump_disable_backtraces
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable core dump backtraces - Count number of files which contain the correct
        section
      ansible.builtin.set_fact:
        count_of_systemd_dropin_files_with_section: '{{systemd_dropin_files_with_section.results
          | map(attribute=''matched'') | list | map(''int'') | sum}}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"systemd" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6
      - PCI-DSS-Req-3.2
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - coredump_disable_backtraces
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable core dump backtraces - Add missing configuration to correct section
      community.general.ini_file:
        path: '{{item}}'
        section: Coredump
        option: ProcessSizeMax
        value: '0'
        state: present
        no_extra_spaces: true
      when:
      - '"kernel" in ansible_facts.packages'
      - '"systemd" in ansible_facts.packages'
      - count_of_systemd_dropin_files_with_section | int > 0
      loop: '{{systemd_dropin_files_with_section.results | sum(attribute=''files'', start=[])
        | map(attribute=''path'') | list }}'
      tags:
      - NIST-800-53-CM-6
      - PCI-DSS-Req-3.2
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - coredump_disable_backtraces
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable core dump backtraces - Add configuration to new remediation file
      community.general.ini_file:
        path: /etc/systemd/coredump.conf.d/complianceascode_hardening.conf
        section: Coredump
        option: ProcessSizeMax
        value: '0'
        state: present
        no_extra_spaces: true
        create: true
      when:
      - '"kernel" in ansible_facts.packages'
      - '"systemd" in ansible_facts.packages'
      - count_of_systemd_dropin_files_with_section | int == 0
      tags:
      - NIST-800-53-CM-6
      - PCI-DSS-Req-3.2
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - coredump_disable_backtraces
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Disable storing core dump [ref]
The `Storage` option in `[Coredump]` section of `/etc/systemd/coredump.conf` or a drop-in file in `/etc/systemd/coredump.conf.d/*.conf` can be set to `none` to disable storing core dumps permanently. Warning: If the `/etc/systemd/coredump.conf` file or a drop-in file under `/etc/systemd/coredump.conf.d/` does not already contain the `[Coredump]` section, the value will not be configured correctly.
Rationale: | A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended, however there may be overriding operational requirements to enable advanced debugging. Permitting temporary enablement of core dumps during such situations should be reviewed through local needs and policy.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_coredump_disable_storage
References: |
nist | CM-6
pcidss | Req-3.2
os-srg | SRG-OS-000480-GPOS-00227
cis | 1.5.3
pcidss4 | 3.3.1.1, 3.3.1, 3.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q systemd; }; then

    found=false

    # set value in all files if they contain section or key
    for f in $(echo -n "/etc/systemd/coredump.conf.d/complianceascode_hardening.conf /etc/systemd/coredump.conf.d/*.conf /etc/systemd/coredump.conf"); do
        if [ ! -e "$f" ]; then
            continue
        fi

        # find key in section and change value
        if grep -qzosP "(?m)^[[:space:]]*\[Coredump\]([^\n\[]*\n+)+?[[:space:]]*Storage" "$f"; then
            if ! grep -qzosP "(?m)^[[:space:]]*Storage[[:space:]]*=[[:space:]]*none" "$f"; then

                sed -i "/^[[:space:]]*Storage/s/\([[:blank:]]*=[[:blank:]]*\).*/\1none/" "$f"

            fi

            found=true

        # find section and add key = value to it
        elif grep -qs "^[[:space:]]*\[Coredump\]" "$f"; then

                sed -i "/^[[:space:]]*\[Coredump\]/a Storage=none" "$f"

                found=true
        fi
    done

    # if section not in any file, append section with key = value to FIRST file in files parameter
    if ! $found ; then
        file=$(echo "/etc/systemd/coredump.conf.d/complianceascode_hardening.conf /etc/systemd/coredump.conf.d/*.conf /etc/systemd/coredump.conf" | cut -f1 -d ' ')
        mkdir -p "$(dirname "$file")"

        echo -e "[Coredump]\nStorage=none" >> "$file"

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6
      - PCI-DSS-Req-3.2
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - coredump_disable_storage
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable storing core dump - Search for a section in files
      ansible.builtin.find:
        paths: '{{item.path}}'
        patterns: '{{item.pattern}}'
        contains: ^\s*\[Coredump\]
        read_whole_file: true
        use_regex: true
      register: systemd_dropin_files_with_section
      loop:
      - path: '{{ ''/etc/systemd/coredump.conf'' | dirname }}'
        pattern: '{{ ''/etc/systemd/coredump.conf'' | basename | regex_escape }}'
      - path: /etc/systemd/coredump.conf.d
        pattern: .*\.conf
      when:
      - '"kernel" in ansible_facts.packages'
      - '"systemd" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6
      - PCI-DSS-Req-3.2
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - coredump_disable_storage
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable storing core dump - Count number of files which contain the correct
        section
      ansible.builtin.set_fact:
        count_of_systemd_dropin_files_with_section: '{{systemd_dropin_files_with_section.results
          | map(attribute=''matched'') | list | map(''int'') | sum}}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"systemd" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6
      - PCI-DSS-Req-3.2
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - coredump_disable_storage
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable storing core dump - Add missing configuration to correct section
      community.general.ini_file:
        path: '{{item}}'
        section: Coredump
        option: Storage
        value: none
        state: present
        no_extra_spaces: true
      when:
      - '"kernel" in ansible_facts.packages'
      - '"systemd" in ansible_facts.packages'
      - count_of_systemd_dropin_files_with_section | int > 0
      loop: '{{systemd_dropin_files_with_section.results | sum(attribute=''files'', start=[])
        | map(attribute=''path'') | list }}'
      tags:
      - NIST-800-53-CM-6
      - PCI-DSS-Req-3.2
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - coredump_disable_storage
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable storing core dump - Add configuration to new remediation file
      community.general.ini_file:
        path: /etc/systemd/coredump.conf.d/complianceascode_hardening.conf
        section: Coredump
        option: Storage
        value: none
        state: present
        no_extra_spaces: true
        create: true
      when:
      - '"kernel" in ansible_facts.packages'
      - '"systemd" in ansible_facts.packages'
      - count_of_systemd_dropin_files_with_section | int == 0
      tags:
      - NIST-800-53-CM-6
      - PCI-DSS-Req-3.2
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - coredump_disable_storage
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
Group Enable ExecShield Group contains 1 rule
[ref] ExecShield describes kernel features that provide protection against exploitation of memory corruption errors such as buffer overflows. These features include random placement of the stack and other memory regions, prevention of execution in memory that should only hold data, and special handling of text buffers. These protections are enabled by default on 32-bit systems and controlled through `sysctl` variables `kernel.exec-shield` and `kernel.randomize_va_space`. On the latest 64-bit systems, `kernel.exec-shield` cannot be enabled or disabled with `sysctl`.
#### Rule Enable Randomized Layout of Virtual Address Space [ref]
To set the runtime status of the `kernel.randomize_va_space` kernel parameter, run the following command:
    $ sudo sysctl -w kernel.randomize_va_space=2
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    kernel.randomize_va_space = 2
Rationale: | Address space layout randomization (ASLR) makes it more difficult for an attacker to predict the location of attack code they have introduced into a process's address space during an attempt at exploitation. Additionally, ASLR makes it more difficult for an attacker to know the location of existing code in order to re-purpose it using return oriented programming (ROP) techniques.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_kernel_randomize_va_space
References: |
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
nerc-cip | CIP-002-5 R1.1, CIP-002-5 R1.2, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 4.1, CIP-004-6 4.2, CIP-004-6 R2.2.3, CIP-004-6 R2.2.4, CIP-004-6 R2.3, CIP-004-6 R4, CIP-005-6 R1, CIP-005-6 R1.1, CIP-005-6 R1.2, CIP-007-3 R3, CIP-007-3 R3.1, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3, CIP-007-3 R8.4, CIP-009-6 R.1.1, CIP-009-6 R4
nist | SC-30, SC-30(2), CM-6(a)
pcidss | Req-2.2.1
os-srg | SRG-OS-000433-GPOS-00193, SRG-OS-000480-GPOS-00227
app-srg-ctr | SRG-APP-000450-CTR-001105
anssi | R9
cis | 1.5.1
ism | 1409
pcidss4 | 3.3.1.1, 3.3.1, 3.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of kernel.randomize_va_space from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*kernel.randomize_va_space.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "kernel.randomize_va_space" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    #
    # Set runtime for kernel.randomize_va_space
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w kernel.randomize_va_space="2"
    fi

    #
    # If kernel.randomize_va_space present in /etc/sysctl.conf, change value to "2"
    #	else, add "kernel.randomize_va_space = 2" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^kernel.randomize_va_space")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "2"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^kernel.randomize_va_space\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^kernel.randomize_va_space\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-30
      - NIST-800-53-SC-30(2)
      - PCI-DSS-Req-2.2.1
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_kernel_randomize_va_space

    - name: Enable Randomized Layout of Virtual Address Space - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-30
      - NIST-800-53-SC-30(2)
      - PCI-DSS-Req-2.2.1
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_kernel_randomize_va_space

    - name: Enable Randomized Layout of Virtual Address Space - Find all files that contain
        kernel.randomize_va_space
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*kernel.randomize_va_space\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-30
      - NIST-800-53-SC-30(2)
      - PCI-DSS-Req-2.2.1
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_kernel_randomize_va_space

    - name: Enable Randomized Layout of Virtual Address Space - Find all files that set
        kernel.randomize_va_space to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*kernel.randomize_va_space\s*=\s*2$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-30
      - NIST-800-53-SC-30(2)
      - PCI-DSS-Req-2.2.1
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_kernel_randomize_va_space

    - name: Enable Randomized Layout of Virtual Address Space - Comment out any occurrences
        of kernel.randomize_va_space from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*kernel.randomize_va_space
        replace: '#kernel.randomize_va_space'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-30
      - NIST-800-53-SC-30(2)
      - PCI-DSS-Req-2.2.1
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_kernel_randomize_va_space

    - name: Enable Randomized Layout of Virtual Address Space - Ensure sysctl kernel.randomize_va_space
        is set to 2
      ansible.posix.sysctl:
        name: kernel.randomize_va_space
        value: '2'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-30
      - NIST-800-53-SC-30(2)
      - PCI-DSS-Req-2.2.1
      - PCI-DSSv4-3.3
      - PCI-DSSv4-3.3.1
      - PCI-DSSv4-3.3.1.1
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_kernel_randomize_va_space
#### Rule Restrict usage of ptrace to descendant processes [ref]
To set the runtime status of the `kernel.yama.ptrace_scope` kernel parameter, run the following command:
    $ sudo sysctl -w kernel.yama.ptrace_scope=1
To make sure that the setting is persistent, add the following line to a file in the directory `/etc/sysctl.d`:
    kernel.yama.ptrace_scope = 1
Rationale: | Unrestricted usage of ptrace allows compromised binaries to run ptrace on another processes of the user. Like this, the attacker can steal sensitive information from the target processes (e.g. SSH sessions, web browser, ...) without any additional assistance from the user (i.e. without resorting to phishing).
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sysctl_kernel_yama_ptrace_scope
References: |
nist | SC-7(10)
ospp | FMT_SMF_EXT.1
os-srg | SRG-OS-000132-GPOS-00067, SRG-OS-000480-GPOS-00227
anssi | R11
cis | 1.5.2
ism | 1409
Remediation Shell script ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # Comment out any occurrences of kernel.yama.ptrace_scope from /etc/sysctl.d/*.conf files

    for f in /etc/sysctl.d/*.conf /run/sysctl.d/*.conf /usr/local/lib/sysctl.d/*.conf /usr/lib/sysctl.d/*.conf; do

      # skip systemd-sysctl symlink (/etc/sysctl.d/99-sysctl.conf -> /etc/sysctl.conf)
      if [[ "$(readlink -f "$f")" == "/etc/sysctl.conf" ]]; then continue; fi

      matching_list=$(grep -P '^(?!#).*[\s]*kernel.yama.ptrace_scope.*$' $f | uniq )
      if ! test -z "$matching_list"; then
        while IFS= read -r entry; do
          escaped_entry=$(sed -e 's|/|\\/|g' <<< "$entry")
          # comment out "kernel.yama.ptrace_scope" matches to preserve user data
          sed -i --follow-symlinks "s/^${escaped_entry}$/# &/g" $f
        done <<< "$matching_list"
      fi
    done

    #
    # Set sysctl config file which to save the desired value
    #

    SYSCONFIG_FILE="/etc/sysctl.conf"

    #
    # Set runtime for kernel.yama.ptrace_scope
    #
    if ! { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        /sbin/sysctl -q -n -w kernel.yama.ptrace_scope="1"
    fi

    #
    # If kernel.yama.ptrace_scope present in /etc/sysctl.conf, change value to "1"
    #	else, add "kernel.yama.ptrace_scope = 1" to /etc/sysctl.conf
    #

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^kernel.yama.ptrace_scope")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "1"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^kernel.yama.ptrace_scope\\>" "${SYSCONFIG_FILE}"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^kernel.yama.ptrace_scope\\>.*/$escaped_formatted_output/gi" "${SYSCONFIG_FILE}"
    else
        if [[ -s "${SYSCONFIG_FILE}" ]] && [[ -n "$(tail -c 1 -- "${SYSCONFIG_FILE}" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "${SYSCONFIG_FILE}"
        fi
        printf '%s\n' "$formatted_output" >> "${SYSCONFIG_FILE}"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | medium
Reboot: | true
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-SC-7(10)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_kernel_yama_ptrace_scope

    - name: Restrict usage of ptrace to descendant processes - Set fact for sysctl paths
      ansible.builtin.set_fact:
        sysctl_paths:
        - /etc/sysctl.d/
        - /run/sysctl.d/
        - /usr/local/lib/sysctl.d/
        - /usr/lib/sysctl.d/
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-SC-7(10)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_kernel_yama_ptrace_scope

    - name: Restrict usage of ptrace to descendant processes - Find all files that contain
        kernel.yama.ptrace_scope
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*kernel.yama.ptrace_scope\s*=\s*.*$'
      register: find_all_values
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-SC-7(10)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_kernel_yama_ptrace_scope

    - name: Restrict usage of ptrace to descendant processes - Find all files that set
        kernel.yama.ptrace_scope to correct value
      ansible.builtin.shell:
        cmd: find -L {{ sysctl_paths | join(" ") }} -type f -name '*.conf' | xargs grep
          -HP '^\s*kernel.yama.ptrace_scope\s*=\s*1$'
      register: find_correct_value
      check_mode: false
      changed_when: false
      failed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-SC-7(10)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_kernel_yama_ptrace_scope

    - name: Restrict usage of ptrace to descendant processes - Comment out any occurrences
        of kernel.yama.ptrace_scope from config files
      ansible.builtin.replace:
        path: '{{ item | split(":") | first }}'
        regexp: ^[\s]*kernel.yama.ptrace_scope
        replace: '#kernel.yama.ptrace_scope'
      loop: '{{ find_all_values.stdout_lines }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - find_correct_value.stdout_lines | length == 0 or find_all_values.stdout_lines
        | length > find_correct_value.stdout_lines | length
      tags:
      - NIST-800-53-SC-7(10)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_kernel_yama_ptrace_scope

    - name: Restrict usage of ptrace to descendant processes - Ensure sysctl kernel.yama.ptrace_scope
        is set to 1
      ansible.posix.sysctl:
        name: kernel.yama.ptrace_scope
        value: '1'
        sysctl_file: /etc/sysctl.conf
        state: present
        reload: true
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-SC-7(10)
      - disable_strategy
      - low_complexity
      - medium_disruption
      - medium_severity
      - reboot_required
      - sysctl_kernel_yama_ptrace_scope
Group SELinux Group contains 8 rules
[ref] SELinux is a feature of the Linux kernel which can be used to guard against misconfigured or compromised programs. SELinux enforces the idea that programs should be limited in what files they can access and what actions they can take. The default SELinux policy, as configured on Amazon Linux 2023, has been sufficiently developed and debugged that it should be usable on almost any system with minimal configuration and a small amount of system administrator training. This policy prevents system services - including most of the common network-visible services such as mail servers, FTP servers, and DNS servers - from accessing files which those services have no valid reason to access. This action alone prevents a huge amount of possible damage from network attacks against services, from trojaned software, and so forth. This guide recommends that SELinux be enabled using the default (targeted) policy on every Amazon Linux 2023 system, unless that system has unusual requirements which make a stronger policy appropriate.
#### Rule Install libselinux Package [ref]
The `libselinux` package can be installed with the following command:
    $ sudo dnf install libselinux
Rationale: | Security-enhanced Linux is a feature of the Linux kernel and a number of utilities with enhanced security functionality designed to add mandatory access controls to Linux. The `libselinux` package contains the core library of the Security-enhanced Linux system.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_package_libselinux_installed
References: |
cis | 1.6.1.1
pcidss4 | 1.2.6, 1.2
Remediation OSBuild Blueprint snippet ⇲
    [[packages]]
    name = "libselinux"
    version = "*"
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if ! rpm -q --quiet "libselinux" ; then
        dnf install -y "libselinux"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    package --add=libselinux
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - enable_strategy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_libselinux_installed

    - name: Ensure libselinux is installed
      ansible.builtin.package:
        name: libselinux
        state: present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - enable_strategy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_libselinux_installed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include install_libselinux

    class install_libselinux {
      package { 'libselinux':
        ensure => 'installed',
      }
    }
#### Rule Uninstall mcstrans Package [ref]
The `mcstransd` daemon provides category label information to client processes requesting information. The label translations are defined in `/etc/selinux/targeted/setrans.conf`. The `mcstrans` package can be removed with the following command:
    $ sudo dnf remove mcstrans
Rationale: | Since this service is not used very often, disable it to reduce the amount of potentially vulnerable code running on the system.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_package_mcstrans_removed
References: |
cis | 1.6.1.8
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # CAUTION: This remediation script will remove mcstrans
    # from the system, and may remove any packages
    # that depend on mcstrans. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "mcstrans" ; then
    dnf remove -y --noautoremove "mcstrans"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=mcstrans
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - package_mcstrans_removed

    - name: 'Uninstall mcstrans Package: Ensure mcstrans is removed'
      ansible.builtin.package:
        name: mcstrans
        state: absent
      when: '"kernel" in ansible_facts.packages'
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - package_mcstrans_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_mcstrans

    class remove_mcstrans {
      package { 'mcstrans':
        ensure => 'purged',
      }
    }
#### Rule Uninstall setroubleshoot Package [ref]
The SETroubleshoot service notifies desktop users of SELinux denials. The service provides information around configuration errors, unauthorized intrusions, and other potential errors. The `setroubleshoot` package can be removed with the following command:
    $ sudo dnf remove setroubleshoot
Rationale: | The SETroubleshoot service is an unnecessary daemon to have running on a server, especially if X Windows is removed or disabled.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_package_setroubleshoot_removed
References: |
anssi | R49
cis | 1.6.1.7
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    # CAUTION: This remediation script will remove setroubleshoot
    # from the system, and may remove any packages
    # that depend on setroubleshoot. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "setroubleshoot" ; then
    dnf remove -y --noautoremove "setroubleshoot"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=setroubleshoot
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - package_setroubleshoot_removed

    - name: 'Uninstall setroubleshoot Package: Ensure setroubleshoot is removed'
      ansible.builtin.package:
        name: setroubleshoot
        state: absent
      when: '"kernel" in ansible_facts.packages'
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - package_setroubleshoot_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_setroubleshoot

    class remove_setroubleshoot {
      package { 'setroubleshoot':
        ensure => 'purged',
      }
    }
#### Rule Ensure SELinux Not Disabled in /etc/default/grub [ref]
SELinux can be disabled at boot time by an argument in `/etc/default/grub`. Remove any instances of `selinux=0` from the kernel arguments in that file to prevent SELinux from being disabled at boot.
Rationale: | Disabling a major host protection feature, such as SELinux, at boot time prevents it from confining system services at boot time. Further, it increases the chances that it will remain off during system operation.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_grub2_enable_selinux
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9
cobit5 | APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01
cui | 3.1.2, 3.7.2
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
isa-62443-2009 | 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nist | AC-3, AC-3(3)(a)
nist-csf | DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4
cis | 1.6.1.2
pcidss4 | 1.2.6, 1.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q grub2-common; }; then

    sed -i --follow-symlinks "s/selinux=0//gI" /etc/default/grub /etc/grub2.cfg /etc/grub.d/*
    sed -i --follow-symlinks "s/enforcing=0//gI" /etc/default/grub /etc/grub2.cfg /etc/grub.d/*

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - grub2_enable_selinux
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure SELinux Not Disabled in /etc/default/grub - Find /etc/grub.d/ files
      ansible.builtin.find:
        paths:
        - /etc/grub.d/
        follow: true
      register: result_grub_d
      when:
      - '"kernel" in ansible_facts.packages'
      - '"grub2-common" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - grub2_enable_selinux
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure SELinux Not Disabled in /etc/default/grub - Ensure SELinux Not Disabled
        in /etc/grub.d/ files
      ansible.builtin.replace:
        dest: '{{ item.path }}'
        regexp: (selinux|enforcing)=0
      with_items:
      - '{{ result_grub_d.files }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"grub2-common" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - grub2_enable_selinux
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure SELinux Not Disabled in /etc/default/grub - Check if /etc/grub2.cfg
        exists
      ansible.builtin.stat:
        path: /etc/grub2.cfg
      register: result_grub2_cfg_present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"grub2-common" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - grub2_enable_selinux
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure SELinux Not Disabled in /etc/default/grub - Check if /etc/default/grub
        exists
      ansible.builtin.stat:
        path: /etc/default/grub
      register: result_default_grub_present
      when:
      - '"kernel" in ansible_facts.packages'
      - '"grub2-common" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - grub2_enable_selinux
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure SELinux Not Disabled in /etc/default/grub - Ensure SELinux Not Disabled
        in /etc/grub2.cfg
      ansible.builtin.replace:
        dest: /etc/grub2.cfg
        regexp: (selinux|enforcing)=0
      when:
      - '"kernel" in ansible_facts.packages'
      - '"grub2-common" in ansible_facts.packages'
      - result_grub2_cfg_present.stat.exists
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - grub2_enable_selinux
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure SELinux Not Disabled in /etc/default/grub - Ensure SELinux Not Disabled
        in /etc/default/grub
      ansible.builtin.replace:
        dest: /etc/default/grub
        regexp: (selinux|enforcing)=0
      when:
      - '"kernel" in ansible_facts.packages'
      - '"grub2-common" in ansible_facts.packages'
      - result_default_grub_present.stat.exists
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - grub2_enable_selinux
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure No Daemons are Unconfined by SELinux [ref]
Daemons for which the SELinux policy does not contain rules will inherit the context of the parent process. Because daemons are launched during startup and descend from the `init` process, they inherit the `unconfined_service_t` context. To check for unconfined daemons, run the following command:
    $ sudo ps -eZ | grep "unconfined_service_t"
It should produce no output in a well-configured system. Warning: Automatic remediation of this control is not available. Remediation can be achieved by amending SELinux policy or stopping the unconfined daemons as outlined above.
Rationale: | Daemons which run with the `unconfined_service_t` context may cause AVC denials, or allow privileges that the daemon does not require.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_selinux_confinement_of_daemons
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 3, 5, 6, 9
cobit5 | APO01.06, APO11.04, BAI03.05, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.06, MEA02.01
cui | 3.1.2, 3.1.5, 3.7.2
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
isa-62443-2009 | 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 5.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.5.1, A.12.6.2, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-7(a), CM-7(b), CM-6(a), AC-3(3)(a), AC-6
nist-csf | PR.AC-4, PR.DS-5, PR.IP-1, PR.PT-1, PR.PT-3
cis | 1.6.1.6
pcidss4 | 1.2.6, 1.2
#### Rule Ensure SELinux is Not Disabled [ref]
The SELinux state should be set to `enforcing` or `permissive` at system boot time. In the file `/etc/selinux/config`, add or correct the following line to configure the system to boot into enforcing or permissive mode:
    SELINUX=enforcing
OR
    SELINUX=permissive
Ensure that all files have correct SELinux labels by running:
    fixfiles onboot
Then reboot the system. Warning: In case the SELinux is "disabled", the automated remediation will adopt a more conservative approach and set it to "permissive" in order to avoid any system disruption and give the administrator the opportunity to assess the impact and necessary efforts before setting it to "enforcing", which is strongly recommended.
Rationale: | Running SELinux in disabled mode is strongly discouraged. It prevents enforcing the SELinux controls without a system reboot. It also avoids labeling any persistent objects such as files, making it difficult to enable SELinux in the future.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_selinux_not_disabled
References: |
cis | 1.6.1.4
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if [ -e "/etc/selinux/config" ] ; then

        LC_ALL=C sed -i "/^SELINUX=/Id" "/etc/selinux/config"
    else
        touch "/etc/selinux/config"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/selinux/config"

    cp "/etc/selinux/config" "/etc/selinux/config.bak"
    # Insert at the end of the file
    printf '%s\n' "SELINUX=permissive" >> "/etc/selinux/config"
    # Clean up after ourselves.
    rm "/etc/selinux/config.bak"

    fixfiles onboot

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - high_severity
      - low_complexity
      - low_disruption
      - reboot_required
      - restrict_strategy
      - selinux_not_disabled

    - name: Ensure SELinux is Not Disabled - Check current SELinux state
      ansible.builtin.command:
        cmd: getenforce
      register: current_selinux_state
      check_mode: false
      changed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - high_severity
      - low_complexity
      - low_disruption
      - reboot_required
      - restrict_strategy
      - selinux_not_disabled

    - name: Ensure SELinux is Not Disabled
      block:

      - name: Check for duplicate values
        ansible.builtin.lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: (?i)^SELINUX=
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/selinux/config
        ansible.builtin.lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: (?i)^SELINUX=
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/selinux/config
        ansible.builtin.lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: (?i)^SELINUX=
          line: SELINUX=permissive
          state: present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - high_severity
      - low_complexity
      - low_disruption
      - reboot_required
      - restrict_strategy
      - selinux_not_disabled

    - name: Ensure SELinux is Not Disabled - Mark system to relabel SELinux on next boot
      ansible.builtin.file:
        path: /.autorelabel
        state: touch
        access_time: preserve
        modification_time: preserve
      when:
      - '"kernel" in ansible_facts.packages'
      - current_selinux_state.stdout | lower != "permissive"
      tags:
      - high_severity
      - low_complexity
      - low_disruption
      - reboot_required
      - restrict_strategy
      - selinux_not_disabled
#### Rule Configure SELinux Policy [ref]
The SELinux `targeted` policy is appropriate for general-purpose desktops and servers, as well as systems in many other roles. To configure the system to use this policy, add or correct the following line in `/etc/selinux/config`:
    SELINUXTYPE=targeted
Other policies, such as `mls`, provide additional security labeling and greater confinement but are not compatible with many general-purpose use cases.
Rationale: | Setting the SELinux policy to `targeted` or a more specialized policy ensures the system will confine processes that are likely to be targeted for exploitation, such as network or system services. Note: During the development or debugging of SELinux modules, it is common to temporarily place non-production systems in `permissive` mode. In such temporary cases, SELinux policies should be developed, and once work is completed, the system should be reconfigured to `targeted`.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_selinux_policytype
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9
cobit5 | APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01
cui | 3.1.2, 3.7.2
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
isa-62443-2009 | 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-004-6 R3.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CIP-007-3 R6.5
nist | AC-3, AC-3(3)(a), AU-9, SC-7(21)
nist-csf | DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4
ospp | FMT_MOF_EXT.1
os-srg | SRG-OS-000445-GPOS-00199
app-srg-ctr | SRG-APP-000233-CTR-000585
anssi | R46, R64
bsi | APP.4.4.A4, SYS.1.6.A3, SYS.1.6.A18, SYS.1.6.A21
cis | 1.6.1.3
ism | 1409
pcidss4 | 1.2.6, 1.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    var_selinux_policy_name='targeted'

    if [ -e "/etc/selinux/config" ] ; then

        LC_ALL=C sed -i "/^SELINUXTYPE=/Id" "/etc/selinux/config"
    else
        touch "/etc/selinux/config"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/selinux/config"

    cp "/etc/selinux/config" "/etc/selinux/config.bak"
    # Insert at the end of the file
    printf '%s\n' "SELINUXTYPE=$var_selinux_policy_name" >> "/etc/selinux/config"
    # Clean up after ourselves.
    rm "/etc/selinux/config.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - NIST-800-53-AU-9
      - NIST-800-53-SC-7(21)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - selinux_policytype
    - name: XCCDF Value var_selinux_policy_name # promote to variable
      set_fact:
        var_selinux_policy_name: !!str targeted
      tags:
        - always

    - name: Configure SELinux Policy
      block:

      - name: Check for duplicate values
        ansible.builtin.lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: (?i)^SELINUXTYPE=
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/selinux/config
        ansible.builtin.lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: (?i)^SELINUXTYPE=
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/selinux/config
        ansible.builtin.lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: (?i)^SELINUXTYPE=
          line: SELINUXTYPE={{ var_selinux_policy_name }}
          state: present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - NIST-800-53-AU-9
      - NIST-800-53-SC-7(21)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - selinux_policytype
#### Rule Ensure SELinux State is Enforcing [ref]
The SELinux state should be set to `enforcing` at system boot time. In the file `/etc/selinux/config`, add or correct the following line to configure the system to boot into enforcing mode:
    SELINUX=enforcing
Ensure that all files have correct SELinux labels by running:
    fixfiles onboot
Then reboot the system.
Rationale: | Setting the SELinux state to enforcing ensures SELinux is able to confine potentially compromised processes to the security policy, which is designed to prevent them from causing damage to the system or further elevating their privileges.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_selinux_state
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 3, 4, 5, 6, 8, 9
cobit5 | APO01.06, APO11.04, APO13.01, BAI03.05, DSS01.05, DSS03.01, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06, MEA02.01
cui | 3.1.2, 3.7.2
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3), 164.308(a)(4), 164.310(b), 164.310(c), 164.312(a), 164.312(e)
isa-62443-2009 | 4.2.3.4, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.4, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4, 4.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.1, A.12.1.2, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.2, A.13.1.3, A.13.2.1, A.13.2.2, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-004-6 R3.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CIP-007-3 R6.5
nist | AC-3, AC-3(3)(a), AU-9, SC-7(21)
nist-csf | DE.AE-1, ID.AM-3, PR.AC-4, PR.AC-5, PR.AC-6, PR.DS-5, PR.PT-1, PR.PT-3, PR.PT-4
ospp | FMT_MOF_EXT.1
os-srg | SRG-OS-000445-GPOS-00199, SRG-OS-000134-GPOS-00068
anssi | R37, R79
bsi | APP.4.4.A4, SYS.1.6.A3, SYS.1.6.A18, SYS.1.6.A21
cis | 1.6.1.5
ism | 1409
pcidss4 | 1.2.6, 1.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    var_selinux_state='enforcing'

    if [ -e "/etc/selinux/config" ] ; then

        LC_ALL=C sed -i "/^SELINUX=/Id" "/etc/selinux/config"
    else
        touch "/etc/selinux/config"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/selinux/config"

    cp "/etc/selinux/config" "/etc/selinux/config.bak"
    # Insert at the end of the file
    printf '%s\n' "SELINUX=$var_selinux_state" >> "/etc/selinux/config"
    # Clean up after ourselves.
    rm "/etc/selinux/config.bak"

    fixfiles onboot

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - NIST-800-53-AU-9
      - NIST-800-53-SC-7(21)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
      - selinux_state
    - name: XCCDF Value var_selinux_state # promote to variable
      set_fact:
        var_selinux_state: !!str enforcing
      tags:
        - always

    - name: Ensure SELinux State is Enforcing - Check current SELinux state
      ansible.builtin.command:
        cmd: getenforce
      register: current_selinux_state
      check_mode: false
      changed_when: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - NIST-800-53-AU-9
      - NIST-800-53-SC-7(21)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
      - selinux_state

    - name: Ensure SELinux State is Enforcing
      block:

      - name: Check for duplicate values
        ansible.builtin.lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: (?i)^SELINUX=
          state: absent
        check_mode: true
        changed_when: false
        register: dupes

      - name: Deduplicate values from /etc/selinux/config
        ansible.builtin.lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: (?i)^SELINUX=
          state: absent
        when: dupes.found is defined and dupes.found > 1

      - name: Insert correct line to /etc/selinux/config
        ansible.builtin.lineinfile:
          path: /etc/selinux/config
          create: true
          regexp: (?i)^SELINUX=
          line: SELINUX={{ var_selinux_state }}
          state: present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - NIST-800-53-AU-9
      - NIST-800-53-SC-7(21)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
      - selinux_state

    - name: Ensure SELinux State is Enforcing - Mark system to relabel SELinux on next
        boot
      ansible.builtin.file:
        path: /.autorelabel
        state: touch
        access_time: preserve
        modification_time: preserve
      when:
      - '"kernel" in ansible_facts.packages'
      - current_selinux_state.stdout | lower != var_selinux_state
      tags:
      - NIST-800-171-3.1.2
      - NIST-800-171-3.7.2
      - NIST-800-53-AC-3
      - NIST-800-53-AC-3(3)(a)
      - NIST-800-53-AU-9
      - NIST-800-53-SC-7(21)
      - PCI-DSSv4-1.2
      - PCI-DSSv4-1.2.6
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
      - selinux_state
Group Services Group contains 41 groups and 82 rules
[ref] The best protection against vulnerable software is running less software. This section describes how to review the software which Amazon Linux 2023 installs on a system and disable software which is not needed. It then enumerates the software packages installed on a default Amazon Linux 2023 system and provides guidance about which ones can be safely disabled. Amazon Linux 2023 provides a convenient minimal install option that essentially installs the bare necessities for a functional system. When building Amazon Linux 2023 systems, it is highly recommended to select the minimal packages and then build up the system from there.
Group Avahi Server Group contains 1 group and 1 rule
[ref] The Avahi daemon implements the DNS Service Discovery and Multicast DNS protocols, which provide service and host discovery on a network. It allows a system to automatically identify resources on the network, such as printers or web servers. This capability is also known as mDNSresponder and is a major part of Zeroconf networking.
Group Disable Avahi Server if Possible Group contains 1 rule
[ref] Because the Avahi daemon service keeps an open network port, it is subject to network attacks. Disabling it can reduce the system's vulnerability to such attacks.
#### Rule Uninstall avahi Server Package [ref]
If the system does not need to have an Avahi server which implements the DNS Service Discovery and Multicast DNS protocols, the avahi-autoipd and avahi packages can be uninstalled.
Rationale: | Automatic discovery of network services is not normally required for system functionality. It is recommended to remove this package to reduce the potential attack surface.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_package_avahi_removed
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 2.2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove avahi
    # from the system, and may remove any packages
    # that depend on avahi. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "avahi" ; then
    dnf remove -y --noautoremove "avahi"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=avahi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall avahi Server Package: Ensure avahi is removed'
      ansible.builtin.package:
        name: avahi
        state: absent
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_avahi_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_avahi

    class remove_avahi {
      package { 'avahi':
        ensure => 'purged',
      }
    }
Group Cron and At Daemons Group contains 1 group and 28 rules
[ref] The cron and at services are used to allow commands to be executed at a later time. The cron service is required by almost all systems to perform necessary maintenance tasks, while at may or may not be required on a given system. Both daemons should be configured defensively.
Group Restrict at and cron to Authorized Users if Necessary Group contains 9 rules
- [ref] The `/etc/cron.allow` and `/etc/at.allow` files contain lists of users who are allowed to use `cron` and at to delay execution of processes. If these files exist and if the corresponding files `/etc/cron.deny` and `/etc/at.deny` do not exist, then only users listed in the relevant allow files can run the crontab and `at` commands to submit jobs to be run at scheduled intervals. On many systems, only the system administrator needs the ability to schedule jobs. Note that even if a given user is not listed in `cron.allow`, cron jobs can still be run as that user. The `cron.allow` file controls only administrative access to the crontab command for scheduling and modifying cron jobs. To restrict `at` and `cron` to only authorized users: Remove the `cron.deny` file:
      $ sudo rm /etc/cron.deny
- Edit `/etc/cron.allow`, adding one line for each user allowed to use the crontab command to create cron jobs. Remove the `at.deny` file:
      $ sudo rm /etc/at.deny
Edit `/etc/at.allow`, adding one line for each user allowed to use the at command to create at jobs.
#### Rule Ensure that /etc/at.deny does not exist [ref]
The file `/etc/at.deny` should not exist. Use `/etc/at.allow` instead.
Rationale: | Access to `at` should be restricted. It is easier to manage an allow list than a deny list.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_at_deny_not_exist
References: |
cis | 4.1.9
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if [[ -f  /etc/at.deny ]]; then
            rm /etc/at.deny
        fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - disable_strategy
      - file_at_deny_not_exist
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure that /etc/at.deny does not exist - Remove /etc/at.deny
      ansible.builtin.file:
        path: /etc/at.deny
        state: absent
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - disable_strategy
      - file_at_deny_not_exist
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Ensure that /etc/cron.allow exists [ref]
The file `/etc/cron.allow` should exist and should be used instead of `/etc/cron.deny`.
Rationale: | Access to `crontab` should be restricted. It is easier to manage an allow list than a deny list. Therefore, `/etc/cron.allow` needs to be created and used instead of `/etc/cron.deny`. Regardless of the existence of any of these files, the root administrative user is always allowed to setup a crontab.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_cron_allow_exists
References: |
cis | 4.1.8
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    touch /etc/cron.allow
        chown 0 /etc/cron.allow
        chmod 0640 /etc/cron.allow

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - disable_strategy
      - file_cron_allow_exists
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure that /etc/cron.allow exists - Add empty /etc/cron.allow
      ansible.builtin.file:
        path: /etc/cron.allow
        state: touch
        owner: '0'
        mode: '0640'
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - disable_strategy
      - file_cron_allow_exists
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Ensure that /etc/cron.deny does not exist [ref]
The file `/etc/cron.deny` should not exist. Use `/etc/cron.allow` instead.
Rationale: | Access to `cron` should be restricted. It is easier to manage an allow list than a deny list.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_cron_deny_not_exist
References: |
cis | 4.1.8
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if [[ -f  /etc/cron.deny ]]; then
            rm /etc/cron.deny
        fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - disable_strategy
      - file_cron_deny_not_exist
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure that /etc/cron.deny does not exist - Remove /etc/cron.deny
      ansible.builtin.file:
        path: /etc/cron.deny
        state: absent
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - disable_strategy
      - file_cron_deny_not_exist
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns /etc/at.allow file [ref]
If `/etc/at.allow` exists, it must be group-owned by `root`. To properly set the group owner of `/etc/at.allow`, run the command:
    $ sudo chgrp root /etc/at.allow
Rationale: | If the owner of the at.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_at_allow
References: |
cis | 4.1.9
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/at.allow" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/at.allow
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_at_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupowner_at_allow_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_at_allow_newgroup: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_at_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/at.allow
      ansible.builtin.stat:
        path: /etc/at.allow
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_at_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/at.allow
      ansible.builtin.file:
        path: /etc/at.allow
        follow: false
        group: '{{ file_groupowner_at_allow_newgroup }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_at_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns /etc/cron.allow file [ref]
If `/etc/cron.allow` exists, it must be group-owned by `root`. To properly set the group owner of `/etc/cron.allow`, run the command:
    $ sudo chgrp root /etc/cron.allow
Rationale: | If the owner of the cron.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_cron_allow
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.8
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/cron.allow" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/cron.allow
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupowner_cron_allow_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_cron_allow_newgroup: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/cron.allow
      ansible.builtin.stat:
        path: /etc/cron.allow
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/cron.allow
      ansible.builtin.file:
        path: /etc/cron.allow
        follow: false
        group: '{{ file_groupowner_cron_allow_newgroup }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify User Who Owns /etc/at.allow file [ref]
If `/etc/at.allow` exists, it must be owned by `root`. To properly set the owner of `/etc/at.allow`, run the command:
    $ sudo chown root /etc/at.allow
Rationale: | If the owner of the at.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_at_allow
References: |
cis | 4.1.9
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/at.allow" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/at.allow
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_at_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_owner_at_allow_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_at_allow_newown: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_at_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/at.allow
      ansible.builtin.stat:
        path: /etc/at.allow
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_at_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/at.allow
      ansible.builtin.file:
        path: /etc/at.allow
        follow: false
        owner: '{{ file_owner_at_allow_newown }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_at_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify User Who Owns /etc/cron.allow file [ref]
If `/etc/cron.allow` exists, it must be owned by `root`. To properly set the owner of `/etc/cron.allow`, run the command:
    $ sudo chown root /etc/cron.allow
Rationale: | If the owner of the cron.allow file is not set to root, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_cron_allow
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.8
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/cron.allow" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/cron.allow
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_owner_cron_allow_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_cron_allow_newown: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/cron.allow
      ansible.builtin.stat:
        path: /etc/cron.allow
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/cron.allow
      ansible.builtin.file:
        path: /etc/cron.allow
        follow: false
        owner: '{{ file_owner_cron_allow_newown }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on /etc/at.allow file [ref]
If `/etc/at.allow` exists, it must have permissions `0640` or more restrictive. To properly set the permissions of `/etc/at.allow`, run the command:
    $ sudo chmod 0640 /etc/at.allow
Rationale: | If the permissions of the at.allow file are not set to 0640 or more restrictive, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_at_allow
References: |
cis | 4.1.9
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    chmod u-xs,g-xws,o-xwrt /etc/at.allow

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_at_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/at.allow
      ansible.builtin.stat:
        path: /etc/at.allow
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_at_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xws,o-xwrt on /etc/at.allow
      ansible.builtin.file:
        path: /etc/at.allow
        mode: u-xs,g-xws,o-xwrt
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_at_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on /etc/cron.allow file [ref]
If `/etc/cron.allow` exists, it must have permissions `0640` or more restrictive. To properly set the permissions of `/etc/cron.allow`, run the command:
    $ sudo chmod 0640 /etc/cron.allow
Rationale: | If the permissions of the cron.allow file are not set to 0640 or more restrictive, the possibility exists for an unauthorized user to view or edit sensitive information.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_cron_allow
References: |
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.8
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    chmod u-xs,g-xws,o-xwrt /etc/cron.allow

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/cron.allow
      ansible.builtin.stat:
        path: /etc/cron.allow
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xws,o-xwrt on /etc/cron.allow
      ansible.builtin.file:
        path: /etc/cron.allow
        mode: u-xs,g-xws,o-xwrt
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_allow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Enable cron Service [ref]
The `crond` service is used to execute commands at preconfigured times. It is required by almost all systems to perform necessary maintenance tasks, such as notifying root of system activity. The `crond` service can be enabled with the following command:
    $ sudo systemctl enable crond.service
Rationale: | Due to its usage for maintenance and security-supporting tasks, enabling the cron daemon is essential.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_service_crond_enabled
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 4.1.1
Remediation OSBuild Blueprint snippet ⇲
    [customizations.services]
    enabled = ["crond"]
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    SYSTEMCTL_EXEC='/usr/bin/systemctl'
    "$SYSTEMCTL_EXEC" unmask 'crond.service'
    if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
      "$SYSTEMCTL_EXEC" start 'crond.service'
    fi
    "$SYSTEMCTL_EXEC" enable 'crond.service'

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_crond_enabled

    - name: Enable cron Service - Enable service crond
      block:

      - name: Gather the package facts
        ansible.builtin.package_facts:
          manager: auto

      - name: Enable cron Service - Enable Service crond
        ansible.builtin.systemd:
          name: crond
          enabled: true
          state: started
          masked: false
        when:
        - '"cronie" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_crond_enabled
      - special_service_block
      when: '"kernel" in ansible_facts.packages'
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include enable_crond

    class enable_crond {
      service {'crond':
        enable => true,
        ensure => 'running',
      }
    }
#### Rule Verify Group Who Owns cron.d [ref]
To properly set the group owner of `/etc/cron.d`, run the command:
    $ sudo chgrp root /etc/cron.d
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_cron_d
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.7
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    find -P /etc/cron.d/ -maxdepth 0 -type d  ! -group 0 -exec chgrp --no-dereference "$newgroup" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_d
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupowner_cron_d_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_cron_d_newgroup: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_d
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/cron.d/
      ansible.builtin.file:
        path: /etc/cron.d/
        follow: false
        state: directory
        group: '{{ file_groupowner_cron_d_newgroup }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_d
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns cron.daily [ref]
To properly set the group owner of `/etc/cron.daily`, run the command:
    $ sudo chgrp root /etc/cron.daily
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_cron_daily
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.4
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    find -P /etc/cron.daily/ -maxdepth 0 -type d  ! -group 0 -exec chgrp --no-dereference "$newgroup" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_daily
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupowner_cron_daily_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_cron_daily_newgroup: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_daily
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/cron.daily/
      ansible.builtin.file:
        path: /etc/cron.daily/
        follow: false
        state: directory
        group: '{{ file_groupowner_cron_daily_newgroup }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_daily
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns cron.hourly [ref]
To properly set the group owner of `/etc/cron.hourly`, run the command:
    $ sudo chgrp root /etc/cron.hourly
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_cron_hourly
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.3
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    find -P /etc/cron.hourly/ -maxdepth 0 -type d  ! -group 0 -exec chgrp --no-dereference "$newgroup" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_hourly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupowner_cron_hourly_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_cron_hourly_newgroup: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_hourly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/cron.hourly/
      ansible.builtin.file:
        path: /etc/cron.hourly/
        follow: false
        state: directory
        group: '{{ file_groupowner_cron_hourly_newgroup }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_hourly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns cron.monthly [ref]
To properly set the group owner of `/etc/cron.monthly`, run the command:
    $ sudo chgrp root /etc/cron.monthly
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_cron_monthly
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.6
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    find -P /etc/cron.monthly/ -maxdepth 0 -type d  ! -group 0 -exec chgrp --no-dereference "$newgroup" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_monthly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupowner_cron_monthly_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_cron_monthly_newgroup: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_monthly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/cron.monthly/
      ansible.builtin.file:
        path: /etc/cron.monthly/
        follow: false
        state: directory
        group: '{{ file_groupowner_cron_monthly_newgroup }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_monthly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns cron.weekly [ref]
To properly set the group owner of `/etc/cron.weekly`, run the command:
    $ sudo chgrp root /etc/cron.weekly
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_cron_weekly
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.5
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    find -P /etc/cron.weekly/ -maxdepth 0 -type d  ! -group 0 -exec chgrp --no-dereference "$newgroup" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_weekly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupowner_cron_weekly_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_cron_weekly_newgroup: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_weekly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/cron.weekly/
      ansible.builtin.file:
        path: /etc/cron.weekly/
        follow: false
        state: directory
        group: '{{ file_groupowner_cron_weekly_newgroup }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_cron_weekly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Who Owns Crontab [ref]
To properly set the group owner of `/etc/crontab`, run the command:
    $ sudo chgrp root /etc/crontab
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_crontab
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.2
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/crontab" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/crontab
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_crontab
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupowner_crontab_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_crontab_newgroup: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_crontab
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/crontab
      ansible.builtin.stat:
        path: /etc/crontab
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_crontab
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/crontab
      ansible.builtin.file:
        path: /etc/crontab
        follow: false
        group: '{{ file_groupowner_crontab_newgroup }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_groupowner_crontab
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Owner on cron.d [ref]
To properly set the owner of `/etc/cron.d`, run the command:
    $ sudo chown root /etc/cron.d
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_cron_d
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.7
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    find -P /etc/cron.d/ -maxdepth 0 -type d  ! -user 0 -exec chown --no-dereference "$newown" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_d
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_owner_cron_d_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_cron_d_newown: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_d
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on directory /etc/cron.d/
      ansible.builtin.file:
        path: /etc/cron.d/
        follow: false
        state: directory
        owner: '{{ file_owner_cron_d_newown }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_d
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Owner on cron.daily [ref]
To properly set the owner of `/etc/cron.daily`, run the command:
    $ sudo chown root /etc/cron.daily
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_cron_daily
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.4
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    find -P /etc/cron.daily/ -maxdepth 0 -type d  ! -user 0 -exec chown --no-dereference "$newown" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_daily
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_owner_cron_daily_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_cron_daily_newown: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_daily
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on directory /etc/cron.daily/
      ansible.builtin.file:
        path: /etc/cron.daily/
        follow: false
        state: directory
        owner: '{{ file_owner_cron_daily_newown }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_daily
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Owner on cron.hourly [ref]
To properly set the owner of `/etc/cron.hourly`, run the command:
    $ sudo chown root /etc/cron.hourly
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_cron_hourly
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.3
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    find -P /etc/cron.hourly/ -maxdepth 0 -type d  ! -user 0 -exec chown --no-dereference "$newown" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_hourly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_owner_cron_hourly_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_cron_hourly_newown: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_hourly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on directory /etc/cron.hourly/
      ansible.builtin.file:
        path: /etc/cron.hourly/
        follow: false
        state: directory
        owner: '{{ file_owner_cron_hourly_newown }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_hourly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Owner on cron.monthly [ref]
To properly set the owner of `/etc/cron.monthly`, run the command:
    $ sudo chown root /etc/cron.monthly
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_cron_monthly
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.6
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    find -P /etc/cron.monthly/ -maxdepth 0 -type d  ! -user 0 -exec chown --no-dereference "$newown" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_monthly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_owner_cron_monthly_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_cron_monthly_newown: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_monthly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on directory /etc/cron.monthly/
      ansible.builtin.file:
        path: /etc/cron.monthly/
        follow: false
        state: directory
        owner: '{{ file_owner_cron_monthly_newown }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_monthly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Owner on cron.weekly [ref]
To properly set the owner of `/etc/cron.weekly`, run the command:
    $ sudo chown root /etc/cron.weekly
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_cron_weekly
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.5
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    find -P /etc/cron.weekly/ -maxdepth 0 -type d  ! -user 0 -exec chown --no-dereference "$newown" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_weekly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_owner_cron_weekly_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_cron_weekly_newown: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_weekly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on directory /etc/cron.weekly/
      ansible.builtin.file:
        path: /etc/cron.weekly/
        follow: false
        state: directory
        owner: '{{ file_owner_cron_weekly_newown }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_cron_weekly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Owner on crontab [ref]
To properly set the owner of `/etc/crontab`, run the command:
    $ sudo chown root /etc/crontab
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct user to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_crontab
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.2
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/crontab" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/crontab
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_crontab
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_owner_crontab_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_crontab_newown: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_crontab
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/crontab
      ansible.builtin.stat:
        path: /etc/crontab
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_crontab
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/crontab
      ansible.builtin.file:
        path: /etc/crontab
        follow: false
        owner: '{{ file_owner_crontab_newown }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_owner_crontab
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on cron.d [ref]
To properly set the permissions of `/etc/cron.d`, run the command:
    $ sudo chmod 0700 /etc/cron.d
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_cron_d
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.7
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    find -H /etc/cron.d/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_d
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/cron.d/ file(s)
      ansible.builtin.command: 'find -P /etc/cron.d/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt  -type
        d '
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_d
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for /etc/cron.d/ file(s)
      ansible.builtin.file:
        path: '{{ item }}'
        mode: u-s,g-xwrs,o-xwrt
        state: directory
      with_items:
      - '{{ files_found.stdout_lines }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_d
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on cron.daily [ref]
To properly set the permissions of `/etc/cron.daily`, run the command:
    $ sudo chmod 0700 /etc/cron.daily
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_cron_daily
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.4
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    find -H /etc/cron.daily/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_daily
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/cron.daily/ file(s)
      ansible.builtin.command: 'find -P /etc/cron.daily/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt  -type
        d '
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_daily
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for /etc/cron.daily/ file(s)
      ansible.builtin.file:
        path: '{{ item }}'
        mode: u-s,g-xwrs,o-xwrt
        state: directory
      with_items:
      - '{{ files_found.stdout_lines }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_daily
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on cron.hourly [ref]
To properly set the permissions of `/etc/cron.hourly`, run the command:
    $ sudo chmod 0700 /etc/cron.hourly
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_cron_hourly
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.3
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    find -H /etc/cron.hourly/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_hourly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/cron.hourly/ file(s)
      ansible.builtin.command: 'find -P /etc/cron.hourly/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt  -type
        d '
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_hourly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for /etc/cron.hourly/ file(s)
      ansible.builtin.file:
        path: '{{ item }}'
        mode: u-s,g-xwrs,o-xwrt
        state: directory
      with_items:
      - '{{ files_found.stdout_lines }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_hourly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on cron.monthly [ref]
To properly set the permissions of `/etc/cron.monthly`, run the command:
    $ sudo chmod 0700 /etc/cron.monthly
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_cron_monthly
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.6
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    find -H /etc/cron.monthly/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_monthly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/cron.monthly/ file(s)
      ansible.builtin.command: 'find -P /etc/cron.monthly/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt  -type
        d '
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_monthly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for /etc/cron.monthly/ file(s)
      ansible.builtin.file:
        path: '{{ item }}'
        mode: u-s,g-xwrs,o-xwrt
        state: directory
      with_items:
      - '{{ files_found.stdout_lines }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_monthly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on cron.weekly [ref]
To properly set the permissions of `/etc/cron.weekly`, run the command:
    $ sudo chmod 0700 /etc/cron.weekly
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_cron_weekly
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.5
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    find -H /etc/cron.weekly/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt -type d -exec chmod u-s,g-xwrs,o-xwrt {} \;

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_weekly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/cron.weekly/ file(s)
      ansible.builtin.command: 'find -P /etc/cron.weekly/ -maxdepth 0 -perm /u+s,g+xwrs,o+xwrt  -type
        d '
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_weekly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for /etc/cron.weekly/ file(s)
      ansible.builtin.file:
        path: '{{ item }}'
        mode: u-s,g-xwrs,o-xwrt
        state: directory
      with_items:
      - '{{ files_found.stdout_lines }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_cron_weekly
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on crontab [ref]
To properly set the permissions of `/etc/crontab`, run the command:
    $ sudo chmod 0600 /etc/crontab
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_crontab
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.1.2
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    chmod u-xs,g-xwrs,o-xwrt /etc/crontab

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_crontab
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/crontab
      ansible.builtin.stat:
        path: /etc/crontab
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_crontab
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xwrs,o-xwrt on /etc/crontab
      ansible.builtin.file:
        path: /etc/crontab
        mode: u-xs,g-xwrs,o-xwrt
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_crontab
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
Group DHCP Group contains 1 group and 1 rule
[ref] The Dynamic Host Configuration Protocol (DHCP) allows systems to request and obtain an IP address and other configuration parameters from a server. This guide recommends configuring networking on clients by manually editing the appropriate files under `/etc/sysconfig`. Use of DHCP can make client systems vulnerable to compromise by rogue DHCP servers, and should be avoided unless necessary. If using DHCP is necessary, however, there are best practices that should be followed to minimize security risk.
Group Disable DHCP Server Group contains 1 rule
[ref] The DHCP server `dhcpd` is not installed or activated by default. If the software was installed and activated, but the system does not need to act as a DHCP server, it should be disabled and removed.
#### Rule Uninstall DHCP Server Package [ref]
If the system does not need to act as a DHCP server, the dhcp package can be uninstalled. The `dhcp` package can be removed with the following command:
    $ sudo dnf remove dhcp
Rationale: | Removing the DHCP server ensures that it cannot be easily or accidentally reactivated and disrupt network operation.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_package_dhcp_removed
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
anssi | R62
cis | 2.2.4
pcidss4 | 2.2.4, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove dhcp
    # from the system, and may remove any packages
    # that depend on dhcp. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "dhcp" ; then
    dnf remove -y --noautoremove "dhcp"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=dhcp
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall DHCP Server Package: Ensure dhcp is removed'
      ansible.builtin.package:
        name: dhcp
        state: absent
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.4
      - disable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_dhcp_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_dhcp

    class remove_dhcp {
      package { 'dhcp':
        ensure => 'purged',
      }
    }
Group DNS Server Group contains 1 group and 2 rules
[ref] Most organizations have an operational need to run at least one nameserver. However, there are many common attacks involving DNS server software, and this server software should be disabled on any system on which it is not needed.
Group Disable DNS Server Group contains 1 rule
[ref] DNS software should be disabled on any systems which does not need to be a nameserver. Note that the BIND DNS server software is not installed on Amazon Linux 2023 by default. The remainder of this section discusses secure configuration of systems which must be nameservers.
#### Rule Uninstall bind Package [ref]
The `named` service is provided by the `bind` package. The `bind` package can be removed with the following command:
    $ sudo dnf remove bind
Rationale: | If there is no need to make DNS server software available, removing it provides a safeguard against its activation.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_package_bind_removed
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 2.2.5
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove bind
    # from the system, and may remove any packages
    # that depend on bind. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "bind" ; then
    dnf remove -y --noautoremove "bind"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=bind
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall bind Package: Ensure bind is removed'
      ansible.builtin.package:
        name: bind
        state: absent
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - package_bind_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_bind

    class remove_bind {
      package { 'bind':
        ensure => 'purged',
      }
    }
#### Rule Uninstall dnsmasq Package [ref]
dnsmasq is a lightweight tool that provides DNS caching, DNS forwarding and DHCP (Dynamic Host Configuration Protocol) services. The `dnsmasq` package can be removed with the following command:
    $ sudo dnf remove dnsmasq
Rationale: | Unless a system is specifically designated to act as a DNS caching, DNS forwarding and/or DHCP server, it is recommended that the package be removed to reduce the potential attack surface.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_package_dnsmasq_removed
References: |
cis | 2.2.14
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove dnsmasq
    # from the system, and may remove any packages
    # that depend on dnsmasq. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "dnsmasq" ; then
    dnf remove -y --noautoremove "dnsmasq"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=dnsmasq
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall dnsmasq Package: Ensure dnsmasq is removed'
      ansible.builtin.package:
        name: dnsmasq
        state: absent
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - package_dnsmasq_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_dnsmasq

    class remove_dnsmasq {
      package { 'dnsmasq':
        ensure => 'purged',
      }
    }
Group FTP Server Group contains 1 group and 2 rules
[ref] FTP is a common method for allowing remote access to files. Like telnet, the FTP protocol is unencrypted, which means that passwords and other data transmitted during the session can be captured and that the session is vulnerable to hijacking. Therefore, running the FTP server software is not recommended. However, there are some FTP server configurations which may be appropriate for some environments, particularly those which allow only read-only anonymous access as a means of downloading data available to the public.
Group Disable vsftpd if Possible Group contains 1 rule
[ref] To minimize attack surface, disable vsftpd if at all possible.
#### Rule Uninstall vsftpd Package [ref]
The `vsftpd` package can be removed with the following command:
     $ sudo dnf remove vsftpd
Rationale: | Removing the `vsftpd` package decreases the risk of its accidental activation.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_package_vsftpd_removed
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a), IA-5(1)(c), IA-5(1).1(v), CM-7, CM-7.1(ii)
nist-csf | PR.IP-1, PR.PT-3
os-srg | SRG-OS-000074-GPOS-00042, SRG-OS-000095-GPOS-00049, SRG-OS-000480-GPOS-00227
cis | 2.2.6
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove vsftpd
    # from the system, and may remove any packages
    # that depend on vsftpd. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "vsftpd" ; then
    dnf remove -y --noautoremove "vsftpd"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=vsftpd
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall vsftpd Package: Ensure vsftpd is removed'
      ansible.builtin.package:
        name: vsftpd
        state: absent
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-CM-7.1(ii)
      - NIST-800-53-IA-5(1)(c)
      - NIST-800-53-IA-5(1).1(v)
      - disable_strategy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_vsftpd_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_vsftpd

    class remove_vsftpd {
      package { 'vsftpd':
        ensure => 'purged',
      }
    }
#### Rule Remove ftp Package [ref]
FTP (File Transfer Protocol) is a traditional and widely used standard tool for transferring files between a server and clients over a network, especially where no authentication is necessary (permits anonymous users to connect to a server). The `ftp` package can be removed with the following command:
    $ sudo dnf remove ftp
Rationale: | FTP does not protect the confidentiality of data or authentication credentials. It is recommended SFTP be used if file transfer is required. Unless there is a need to run the system as a FTP server (for example, to allow anonymous downloads), it is recommended that the package be removed to reduce the potential attack surface.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_package_ftp_removed
References: |
cis | 2.3.3
pcidss4 | 2.2.4, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove ftp
    # from the system, and may remove any packages
    # that depend on ftp. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "ftp" ; then
    dnf remove -y --noautoremove "ftp"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=ftp
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Remove ftp Package: Ensure ftp is removed'
      ansible.builtin.package:
        name: ftp
        state: absent
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.4
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - package_ftp_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_ftp

    class remove_ftp {
      package { 'ftp':
        ensure => 'purged',
      }
    }
Group Web Server Group contains 2 groups and 2 rules
[ref] The web server is responsible for providing access to content via the HTTP protocol. Web servers represent a significant security risk because: The HTTP port is commonly probed by malicious sources Web server software is very complex, and includes a long history of vulnerabilities The HTTP protocol is unencrypted and vulnerable to passive monitoring The system's default web server software is Apache 2 and is provided in the RPM package `httpd`.
Group Disable Apache if Possible Group contains 1 rule
[ref] If Apache was installed and activated, but the system does not need to act as a web server, then it should be disabled and removed from the system.
#### Rule Uninstall httpd Package [ref]
The `httpd` package can be removed with the following command:
    $ sudo dnf remove httpd
Rationale: | If there is no need to make the web server software available, removing it provides a safeguard against its activation.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_package_httpd_removed
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 2.2.8
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove httpd
    # from the system, and may remove any packages
    # that depend on httpd. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "httpd" ; then
    dnf remove -y --noautoremove "httpd"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=httpd
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall httpd Package: Ensure httpd is removed'
      ansible.builtin.package:
        name: httpd
        state: absent
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_httpd_removed
      - unknown_severity
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_httpd

    class remove_httpd {
      package { 'httpd':
        ensure => 'purged',
      }
    }
Group Disable NGINX if Possible Group contains 1 rule
[ref] If NGINX was installed and activated, but the system does not need to act as a web server, then it should be removed from the system.
#### Rule Uninstall nginx Package [ref]
The `nginx` package can be removed with the following command:
    $ sudo dnf remove nginx
Rationale: | If there is no need to make the web server software available, removing it provides a safeguard against its activation.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_package_nginx_removed
References: |
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 2.2.8
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove nginx
    # from the system, and may remove any packages
    # that depend on nginx. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "nginx" ; then
    dnf remove -y --noautoremove "nginx"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=nginx
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall nginx Package: Ensure nginx is removed'
      ansible.builtin.package:
        name: nginx
        state: absent
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_nginx_removed
      - unknown_severity
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_nginx

    class remove_nginx {
      package { 'nginx':
        ensure => 'purged',
      }
    }
Group IMAP and POP3 Server Group contains 2 groups and 2 rules
[ref] Dovecot provides IMAP and POP3 services. It is not installed by default. The project page at http://www.dovecot.org contains more detailed information about Dovecot configuration.
Group Disable Cyrus IMAP Group contains 1 rule
[ref] If the system does not need to operate as an IMAP or POP3 server, the Cyrus IMAP software should be removed.
#### Rule Uninstall cyrus-imapd Package [ref]
The `cyrus-imapd` package can be removed with the following command:
    $ sudo dnf remove cyrus-imapd
Rationale: | If there is no need to make the cyrus-imapd software available, removing it provides a safeguard against its activation.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_package_cyrus-imapd_removed
References: |
cis | 2.2.9
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove cyrus-imapd
    # from the system, and may remove any packages
    # that depend on cyrus-imapd. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "cyrus-imapd" ; then
    dnf remove -y --noautoremove "cyrus-imapd"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=cyrus-imapd
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall cyrus-imapd Package: Ensure cyrus-imapd is removed'
      ansible.builtin.package:
        name: cyrus-imapd
        state: absent
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_cyrus-imapd_removed
      - unknown_severity
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_cyrus-imapd

    class remove_cyrus-imapd {
      package { 'cyrus-imapd':
        ensure => 'purged',
      }
    }
Group Disable Dovecot Group contains 1 rule
[ref] If the system does not need to operate as an IMAP or POP3 server, the dovecot software should be disabled and removed.
#### Rule Uninstall dovecot Package [ref]
The `dovecot` package can be removed with the following command:
    $ sudo dnf remove dovecot
Rationale: | If there is no need to make the Dovecot software available, removing it provides a safeguard against its activation.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_package_dovecot_removed
References: |
cis | 2.2.9
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove dovecot
    # from the system, and may remove any packages
    # that depend on dovecot. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "dovecot" ; then
    dnf remove -y --noautoremove "dovecot"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=dovecot
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall dovecot Package: Ensure dovecot is removed'
      ansible.builtin.package:
        name: dovecot
        state: absent
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_dovecot_removed
      - unknown_severity
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_dovecot

    class remove_dovecot {
      package { 'dovecot':
        ensure => 'purged',
      }
    }
Group LDAP Group contains 1 group and 1 rule
[ref] LDAP is a popular directory service, that is, a standardized way of looking up information from a central database. Amazon Linux 2023 includes software that enables a system to act as both an LDAP client and server.
Group Configure OpenLDAP Clients Group contains 1 rule
[ref] This section provides information on which security settings are important to configure in OpenLDAP clients by manually editing the appropriate configuration files. Amazon Linux 2023 provides an automated configuration tool called authconfig and a graphical wrapper for authconfig called `system-config-authentication`. However, these tools do not provide as much control over configuration as manual editing of configuration files. The authconfig tools do not allow you to specify locations of SSL certificate files, which is useful when trying to use SSL cleanly across several protocols. Installation and configuration of OpenLDAP on Amazon Linux 2023 is available at Warning: Before configuring any system to be an LDAP client, ensure that a working LDAP server is present on the network.
#### Rule Ensure LDAP client is not installed [ref]
The Lightweight Directory Access Protocol (LDAP) is a service that provides a method for looking up information from a central database. The `openldap-clients` package can be removed with the following command:
    $ sudo dnf remove openldap-clients
Rationale: | If the system does not need to act as an LDAP client, it is recommended that the software is removed to reduce the potential attack surface.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_package_openldap-clients_removed
References: |
cis | 2.3.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove openldap-clients
    # from the system, and may remove any packages
    # that depend on openldap-clients. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "openldap-clients" ; then
    dnf remove -y --noautoremove "openldap-clients"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=openldap-clients
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Ensure LDAP client is not installed: Ensure openldap-clients is removed'
      ansible.builtin.package:
        name: openldap-clients
        state: absent
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - package_openldap-clients_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_openldap-clients

    class remove_openldap-clients {
      package { 'openldap-clients':
        ensure => 'purged',
      }
    }
Group Mail Server Software Group contains 1 group and 2 rules
[ref] Mail servers are used to send and receive email over the network. Mail is a very common service, and Mail Transfer Agents (MTAs) are obvious targets of network attack. Ensure that systems are not running MTAs unnecessarily, and configure needed MTAs as defensively as possible. Very few systems at any site should be configured to directly receive email over the network. Users should instead use mail client programs to retrieve email from a central server that supports protocols such as IMAP or POP3. However, it is normal for most systems to be independently capable of sending email, for instance so that cron jobs can report output to an administrator. Most MTAs, including Postfix, support a submission-only mode in which mail can be sent from the local system to a central site MTA (or directly delivered to a local account), but the system still cannot receive mail directly over a network. The `alternatives` program in Amazon Linux 2023 permits selection of other mail server software (such as Sendmail), but Postfix is the default and is preferred. Postfix was coded with security in mind and can also be more effectively contained by SELinux as its modular design has resulted in separate processes performing specific actions. More information is available on its website, http://www.postfix.org.
Group Configure SMTP For Mail Clients Group contains 1 rule
[ref] This section discusses settings for Postfix in a submission-only e-mail configuration.
#### Rule Disable Postfix Network Listening [ref]
Edit the file `/etc/postfix/main.cf` to ensure that only the following `inet_interfaces` line appears:
    inet_interfaces = loopback-only
Rationale: | This ensures `postfix` accepts mail messages (such as cron job reports) from the local system only, and not from the network, which protects it from network attack.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_postfix_network_listening_disabled
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
anssi | R74
cis | 2.2.15
pcidss4 | 1.4.2, 1.4
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q postfix; }; then

    var_postfix_inet_interfaces='loopback-only'

    if [ -e "/etc/postfix/main.cf" ] ; then

        LC_ALL=C sed -i "/^\s*inet_interfaces\s\+=\s\+/Id" "/etc/postfix/main.cf"
    else
        touch "/etc/postfix/main.cf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/postfix/main.cf"

    cp "/etc/postfix/main.cf" "/etc/postfix/main.cf.bak"
    # Insert at the end of the file
    printf '%s\n' "inet_interfaces=$var_postfix_inet_interfaces" >> "/etc/postfix/main.cf"
    # Clean up after ourselves.
    rm "/etc/postfix/main.cf.bak"

    systemctl restart postfix

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - postfix_network_listening_disabled
      - restrict_strategy
    - name: XCCDF Value var_postfix_inet_interfaces # promote to variable
      set_fact:
        var_postfix_inet_interfaces: !!str loopback-only
      tags:
        - always

    - name: Gather list of packages
      ansible.builtin.package_facts:
        manager: auto
      when:
      - '"kernel" in ansible_facts.packages'
      - '"postfix" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - postfix_network_listening_disabled
      - restrict_strategy

    - name: Make changes to Postfix configuration file
      ansible.builtin.lineinfile:
        path: /etc/postfix/main.cf
        create: false
        regexp: (?i)^inet_interfaces\s*=\s.*
        line: inet_interfaces = {{ var_postfix_inet_interfaces }}
        state: present
        insertafter: ^inet_interfaces\s*=\s.*
      when:
      - '"kernel" in ansible_facts.packages'
      - '"postfix" in ansible_facts.packages'
      - '"postfix" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-1.4
      - PCI-DSSv4-1.4.2
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - postfix_network_listening_disabled
      - restrict_strategy
#### Rule Ensure Mail Transfer Agent is not Listening on any non-loopback Address [ref]
Mail Transfer Agents (MTA), such as sendmail and Postfix, are used to listen for incoming mail and transfer the messages to the appropriate user or mail server. If the system is not intended to be a mail server, it is recommended that the MTA be configured to only process local mail.
Rationale: | The software for all Mail Transfer Agents is complex and most have a long history of security issues. While it is important to ensure that the system can process local mail messages, it is not necessary to have the MTA's daemon listening on a port unless the server is intended to be a mail server that receives and processes mail from other systems.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_has_nonlocal_mta
References: |
cis | 2.2.15
Group NFS and RPC Group contains 4 groups and 2 rules
[ref] The Network File System is a popular distributed filesystem for the Unix environment, and is very widely deployed. This section discusses the circumstances under which it is possible to disable NFS and its dependencies, and then details steps which should be taken to secure NFS's configuration. This section is relevant to systems operating as NFS clients, as well as to those operating as NFS servers.
Group Disable All NFS Services if Possible Group contains 1 group and 1 rule
[ref] If there is not a reason for the system to operate as either an NFS client or an NFS server, follow all instructions in this section to disable subsystems required by NFS. Warning: The steps in this section will prevent a system from operating as either an NFS client or an NFS server. Only perform these steps on systems which do not need NFS at all.
Group Disable Services Used Only by NFS Group contains 1 rule
[ref] If NFS is not needed, disable the NFS client daemons nfslock, rpcgssd, and rpcidmapd. All of these daemons run with elevated privileges, and many listen for network connections. If they are not needed, they should be disabled to improve system security posture.
#### Rule Disable rpcbind Service [ref]
The rpcbind utility maps RPC services to the ports on which they listen. RPC processes notify rpcbind when they start, registering the ports they are listening on and the RPC program numbers they expect to serve. The rpcbind service redirects the client to the proper port number so it can communicate with the requested service. If the system does not require RPC (such as for NFS servers) then this service should be disabled. The `rpcbind` service can be disabled with the following command:
    $ sudo systemctl mask --now rpcbind.service
Rationale: | If the system does not require rpc based services, it is recommended that rpcbind be disabled to reduce the attack surface.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_service_rpcbind_disabled
References: |
cis | 2.2.17
pcidss4 | 2.2.4, 2.2
Remediation OSBuild Blueprint snippet ⇲
    [customizations.services]
    masked = ["rpcbind"]
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    SYSTEMCTL_EXEC='/usr/bin/systemctl'
    if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
      "$SYSTEMCTL_EXEC" stop 'rpcbind.service'
    fi
    "$SYSTEMCTL_EXEC" disable 'rpcbind.service'
    "$SYSTEMCTL_EXEC" mask 'rpcbind.service'
    # Disable socket activation if we have a unit file for it
    if "$SYSTEMCTL_EXEC" -q list-unit-files rpcbind.socket; then
        if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
          "$SYSTEMCTL_EXEC" stop 'rpcbind.socket'
        fi
        "$SYSTEMCTL_EXEC" mask 'rpcbind.socket'
    fi
    # The service may not be running because it has been started and failed,
    # so let's reset the state so OVAL checks pass.
    # Service should be 'inactive', not 'failed' after reboot though.
    "$SYSTEMCTL_EXEC" reset-failed 'rpcbind.service' || true

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.4
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - service_rpcbind_disabled

    - name: Disable rpcbind Service - Disable service rpcbind
      block:

      - name: Disable rpcbind Service - Collect systemd Services Present in the System
        ansible.builtin.command: systemctl -q list-unit-files --type service
        register: service_exists
        changed_when: false
        failed_when: service_exists.rc not in [0, 1]
        check_mode: false

      - name: Disable rpcbind Service - Ensure rpcbind.service is Masked
        ansible.builtin.systemd:
          name: rpcbind.service
          state: stopped
          enabled: false
          masked: true
        when: service_exists.stdout_lines is search("rpcbind.service", multiline=True)

      - name: Unit Socket Exists - rpcbind.socket
        ansible.builtin.command: systemctl -q list-unit-files rpcbind.socket
        register: socket_file_exists
        changed_when: false
        failed_when: socket_file_exists.rc not in [0, 1]
        check_mode: false

      - name: Disable rpcbind Service - Disable Socket rpcbind
        ansible.builtin.systemd:
          name: rpcbind.socket
          enabled: false
          state: stopped
          masked: true
        when: socket_file_exists.stdout_lines is search("rpcbind.socket", multiline=True)
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.4
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - service_rpcbind_disabled
      - special_service_block
      when: '"kernel" in ansible_facts.packages'
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include disable_rpcbind

    class disable_rpcbind {
      service {'rpcbind':
        enable => false,
        ensure => 'stopped',
      }
    }
Group Configure NFS Clients Group contains 1 group and 1 rule
[ref] The steps in this section are appropriate for systems which operate as NFS clients.
Group Disable NFS Server Daemons Group contains 1 rule
[ref] There is no need to run the NFS server daemons `nfs` and `rpcsvcgssd` except on a small number of properly secured systems designated as NFS servers. Ensure that these daemons are turned off on clients.
#### Rule Disable Network File System (nfs) [ref]
The Network File System (NFS) service allows remote hosts to mount and interact with shared filesystems on the local system. If the local system is not designated as a NFS server then this service should be disabled. The `nfs-server` service can be disabled with the following command:
    $ sudo systemctl mask --now nfs-server.service
Rationale: | Unnecessary services should be disabled to decrease the attack surface of the system.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_service_nfs_disabled
References: |
cis-csc | 11, 12, 14, 15, 16, 18, 3, 5
cobit5 | DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7
iso27001-2013 | A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.AC-4, PR.AC-6, PR.PT-3
cis | 2.2.16
Remediation OSBuild Blueprint snippet ⇲
    [customizations.services]
    masked = ["nfs-server"]
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    SYSTEMCTL_EXEC='/usr/bin/systemctl'
    if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
      "$SYSTEMCTL_EXEC" stop 'nfs-server.service'
    fi
    "$SYSTEMCTL_EXEC" disable 'nfs-server.service'
    "$SYSTEMCTL_EXEC" mask 'nfs-server.service'
    # Disable socket activation if we have a unit file for it
    if "$SYSTEMCTL_EXEC" -q list-unit-files nfs-server.socket; then
        if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
          "$SYSTEMCTL_EXEC" stop 'nfs-server.socket'
        fi
        "$SYSTEMCTL_EXEC" mask 'nfs-server.socket'
    fi
    # The service may not be running because it has been started and failed,
    # so let's reset the state so OVAL checks pass.
    # Service should be 'inactive', not 'failed' after reboot though.
    "$SYSTEMCTL_EXEC" reset-failed 'nfs-server.service' || true

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - service_nfs_disabled
      - unknown_severity

    - name: Disable Network File System (nfs) - Disable service nfs-server
      block:

      - name: Disable Network File System (nfs) - Collect systemd Services Present in
          the System
        ansible.builtin.command: systemctl -q list-unit-files --type service
        register: service_exists
        changed_when: false
        failed_when: service_exists.rc not in [0, 1]
        check_mode: false

      - name: Disable Network File System (nfs) - Ensure nfs-server.service is Masked
        ansible.builtin.systemd:
          name: nfs-server.service
          state: stopped
          enabled: false
          masked: true
        when: service_exists.stdout_lines is search("nfs-server.service", multiline=True)

      - name: Unit Socket Exists - nfs-server.socket
        ansible.builtin.command: systemctl -q list-unit-files nfs-server.socket
        register: socket_file_exists
        changed_when: false
        failed_when: socket_file_exists.rc not in [0, 1]
        check_mode: false

      - name: Disable Network File System (nfs) - Disable Socket nfs-server
        ansible.builtin.systemd:
          name: nfs-server.socket
          enabled: false
          state: stopped
          masked: true
        when: socket_file_exists.stdout_lines is search("nfs-server.socket", multiline=True)
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - service_nfs_disabled
      - special_service_block
      - unknown_severity
      when: '"kernel" in ansible_facts.packages'
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include disable_nfs-server

    class disable_nfs-server {
      service {'nfs-server':
        enable => false,
        ensure => 'stopped',
      }
    }
Group Network Time Protocol Group contains 2 rules
[ref] The Network Time Protocol is used to manage the system clock over a network. Computer clocks are not very accurate, so time will drift unpredictably on unmanaged systems. Central time protocols can be used both to ensure that time is consistent among a network of systems, and that their time is consistent with the outside world. If every system on a network reliably reports the same time, then it is much easier to correlate log messages in case of an attack. In addition, a number of cryptographic protocols (such as Kerberos) use timestamps to prevent certain types of attacks. If your network does not have synchronized time, these protocols may be unreliable or even unusable. Depending on the specifics of the network, global time accuracy may be just as important as local synchronization, or not very important at all. If your network is connected to the Internet, using a public timeserver (or one provided by your enterprise) provides globally accurate timestamps which may be essential in investigating or responding to an attack which originated outside of your network. A typical network setup involves a small number of internal systems operating as NTP servers, and the remainder obtaining time information from those internal servers. There is a choice between the daemons `ntpd` and `chronyd`, which are available from the repositories in the `ntp` and `chrony` packages respectively. The default `chronyd` daemon can work well when external time references are only intermittently accessible, can perform well even when the network is congested for longer periods of time, can usually synchronize the clock faster and with better time accuracy, and quickly adapts to sudden changes in the rate of the clock, for example, due to changes in the temperature of the crystal oscillator. `Chronyd` should be considered for all systems which are frequently suspended or otherwise intermittently disconnected and reconnected to a network. Mobile and virtual systems for example. The `ntpd` NTP daemon fully supports NTP protocol version 4 (RFC 5905), including broadcast, multicast, manycast clients and servers, and the orphan mode. It also supports extra authentication schemes based on public-key cryptography (RFC 5906). The NTP daemon (`ntpd`) should be considered for systems which are normally kept permanently on. Systems which are required to use broadcast or multicast IP, or to perform authentication of packets with the `Autokey` protocol, should consider using `ntpd`. Refer to https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/set-time.html for more detailed comparison of features of `chronyd` and `ntpd` daemon features respectively, and for further guidance how to choose between the two NTP daemons. The upstream manual pages at https://chrony-project.org/documentation.html for `chronyd` and http://www.ntp.org for `ntpd` provide additional information on the capabilities and configuration of each of the NTP daemons.
#### Rule A remote time server for Chrony is configured [ref]
`Chrony` is a daemon which implements the Network Time Protocol (NTP). It is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More information on `chrony` can be found at https://chrony-project.org/. `Chrony` can be configured to be a client and/or a server. Add or edit server or pool lines to `/etc/chrony.conf` as appropriate:
    server <remote-server>
Alternatively, server or pool directives can be specified in files included via `sourcedir` or `confdir` directives in `/etc/chrony.conf`. When using `sourcedir`, create `.sources` files in the specified directory:
    # In /etc/chrony.conf:
    sourcedir /etc/chrony/sources.d

    # In /etc/chrony/sources.d/ntp.sources:
    server 0.pool.ntp.org
When using `confdir`, create `.conf` files in the specified directory:
    # In /etc/chrony.conf:
    confdir /etc/chrony/conf.d

    # In /etc/chrony/conf.d/ntp-servers.conf:
    pool 1.pool.ntp.org
Multiple servers may be configured.
Rationale: | If `chrony` is in use on the system proper configuration is vital to ensuring time synchronization is working properly.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_chronyd_specify_remote_server
References: |
nist | CM-6(a), AU-8(1)(a)
pcidss | Req-10.4.3
os-srg | SRG-OS-000355-GPOS-00143
anssi | R71
cis | 2.1.2
ism | 0988, 1405
pcidss4 | 10.6.2, 10.6
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q chrony; }; then

    var_multiple_time_servers='0.rhel.pool.ntp.org,1.rhel.pool.ntp.org,2.rhel.pool.ntp.org,3.rhel.pool.ntp.org'

    config_file="/etc/chrony.conf"

    if ! grep -q '^[[:space:]]*\(server\|pool\)[[:space:]]\+[[:graph:]]\+' "$config_file" ; then
      if ! grep -q '#[[:space:]]*server' "$config_file" ; then
        for server in $(echo "$var_multiple_time_servers" | tr ',' '\n') ; do
          printf '\nserver %s' "$server" >> "$config_file"
        done
      else
        sed -i 's/#[ \t]*server/server/g' "$config_file"
      fi
      if [[ -s "$config_file" ]] && [[ -n "$(tail -c 1 -- "$config_file" || true)" ]]; then
          LC_ALL=C sed -i --follow-symlinks '$a'\\ "$config_file"
      fi
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AU-8(1)(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.3
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.2
      - chronyd_specify_remote_server
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
    - name: XCCDF Value var_multiple_time_servers # promote to variable
      set_fact:
        var_multiple_time_servers: !!str 0.rhel.pool.ntp.org,1.rhel.pool.ntp.org,2.rhel.pool.ntp.org,3.rhel.pool.ntp.org
      tags:
        - always

    - name: Check if chrony main config has active server/pool entries
      ansible.builtin.command:
        cmd: grep -q '^[[:space:]]*\(server\|pool\)[[:space:]]\+[[:graph:]]\+' /etc/chrony.conf
      register: chrony_conf_has_servers
      changed_when: false
      failed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      tags:
      - NIST-800-53-AU-8(1)(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.3
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.2
      - chronyd_specify_remote_server
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Extract sourcedir paths from chrony configuration
      ansible.builtin.shell:
        cmd: grep '^[[:space:]]*sourcedir[[:space:]]\+' /etc/chrony.conf | awk '{print
          $2}'
      register: chrony_sourcedir_paths
      changed_when: false
      failed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      - chrony_conf_has_servers.rc != 0
      tags:
      - NIST-800-53-AU-8(1)(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.3
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.2
      - chronyd_specify_remote_server
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Check for server/pool entries in sourcedir .sources files
      ansible.builtin.shell:
        cmd: |
          for dir in {{ chrony_sourcedir_paths.stdout_lines | join(' ') }}; do
            if [ -d "$dir" ]; then
              grep -q '^[[:space:]]*\(server\|pool\)[[:space:]]\+[[:graph:]]\+' "$dir"/*.sources 2>/dev/null && exit 0
            fi
          done
          exit 1
      register: chrony_sourcedir_has_servers
      changed_when: false
      failed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      - chrony_conf_has_servers.rc != 0
      - chrony_sourcedir_paths.stdout_lines | length > 0
      tags:
      - NIST-800-53-AU-8(1)(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.3
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.2
      - chronyd_specify_remote_server
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Extract confdir paths from chrony configuration
      ansible.builtin.shell:
        cmd: grep '^[[:space:]]*confdir[[:space:]]\+' /etc/chrony.conf | awk '{print $2}'
      register: chrony_confdir_paths
      changed_when: false
      failed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      - chrony_conf_has_servers.rc != 0
      - (chrony_sourcedir_paths.stdout_lines | default([]) | length == 0 or chrony_sourcedir_has_servers.rc
        != 0)
      tags:
      - NIST-800-53-AU-8(1)(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.3
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.2
      - chronyd_specify_remote_server
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Check for server/pool entries in confdir .conf files
      ansible.builtin.shell:
        cmd: |
          for dir in {{ chrony_confdir_paths.stdout_lines | join(' ') }}; do
            if [ -d "$dir" ]; then
              grep -q '^[[:space:]]*\(server\|pool\)[[:space:]]\+[[:graph:]]\+' "$dir"/*.conf 2>/dev/null && exit 0
            fi
          done
          exit 1
      register: chrony_confdir_has_servers
      changed_when: false
      failed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      - chrony_conf_has_servers.rc != 0
      - chrony_confdir_paths.stdout_lines | default([]) | length > 0
      - (chrony_sourcedir_paths.stdout_lines | default([]) | length == 0 or chrony_sourcedir_has_servers.rc
        != 0)
      tags:
      - NIST-800-53-AU-8(1)(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.3
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.2
      - chronyd_specify_remote_server
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Create sourcedir directory if needed
      ansible.builtin.file:
        path: '{{ chrony_sourcedir_paths.stdout_lines[0] }}'
        state: directory
        mode: '0755'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      - chrony_conf_has_servers.rc != 0
      - chrony_sourcedir_paths.stdout_lines | default([]) | length > 0
      - chrony_sourcedir_has_servers.rc != 0
      tags:
      - NIST-800-53-AU-8(1)(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.3
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.2
      - chronyd_specify_remote_server
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Add remote time servers to sourcedir .sources file
      ansible.builtin.lineinfile:
        path: '{{ chrony_sourcedir_paths.stdout_lines[0] }}/ntp-servers.sources'
        line: server {{ item }}
        state: present
        create: true
        mode: '0644'
      loop: '{{ var_multiple_time_servers.split(",") }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      - chrony_conf_has_servers.rc != 0
      - chrony_sourcedir_paths.stdout_lines | default([]) | length > 0
      - chrony_sourcedir_has_servers.rc != 0
      tags:
      - NIST-800-53-AU-8(1)(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.3
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.2
      - chronyd_specify_remote_server
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Create confdir directory if needed
      ansible.builtin.file:
        path: '{{ chrony_confdir_paths.stdout_lines[0] }}'
        state: directory
        mode: '0755'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      - chrony_conf_has_servers.rc != 0
      - (chrony_sourcedir_paths.stdout_lines | default([]) | length == 0 or chrony_sourcedir_has_servers.rc
        != 0)
      - chrony_confdir_paths.stdout_lines | default([]) | length > 0
      - chrony_confdir_has_servers.rc != 0
      tags:
      - NIST-800-53-AU-8(1)(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.3
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.2
      - chronyd_specify_remote_server
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Add remote time servers to confdir .conf file
      ansible.builtin.lineinfile:
        path: '{{ chrony_confdir_paths.stdout_lines[0] }}/ntp-servers.conf'
        line: server {{ item }}
        state: present
        create: true
        mode: '0644'
      loop: '{{ var_multiple_time_servers.split(",") }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      - chrony_conf_has_servers.rc != 0
      - (chrony_sourcedir_paths.stdout_lines | default([]) | length == 0 or chrony_sourcedir_has_servers.rc
        != 0)
      - chrony_confdir_paths.stdout_lines | default([]) | length > 0
      - chrony_confdir_has_servers.rc != 0
      tags:
      - NIST-800-53-AU-8(1)(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.3
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.2
      - chronyd_specify_remote_server
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Add remote time servers to main chrony configuration
      ansible.builtin.lineinfile:
        path: /etc/chrony.conf
        line: server {{ item }}
        state: present
        create: true
      loop: '{{ var_multiple_time_servers.split(",") }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      - chrony_conf_has_servers.rc != 0
      - (chrony_sourcedir_paths.stdout_lines | default([]) | length == 0 or chrony_sourcedir_has_servers.rc
        != 0)
      - (chrony_confdir_paths.stdout_lines | default([]) | length == 0 or chrony_confdir_has_servers.rc
        != 0)
      tags:
      - NIST-800-53-AU-8(1)(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.3
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.2
      - chronyd_specify_remote_server
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Ensure that chronyd is running under chrony user account [ref]
chrony is a daemon which implements the Network Time Protocol (NTP). It is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More information on chrony can be found at https://chrony-project.org/. Chrony can be configured to be a client and/or a server. To ensure that chronyd is running under chrony user account, add or edit the `OPTIONS` variable in `/etc/sysconfig/chronyd` to include `-u chrony`:
    OPTIONS="-u chrony"
This recommendation only applies if chrony is in use on the system.
Rationale: | If chrony is in use on the system proper configuration is vital to ensuring time synchronization is working properly.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_chronyd_run_as_chrony_user
References: |
cis | 2.1.2
pcidss4 | 10.6.3, 10.6
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q chrony; }; then

    if grep -q 'OPTIONS=.*' /etc/sysconfig/chronyd; then
    	# trying to solve cases where the parameter after OPTIONS
    	#may or may not be enclosed in quotes
    	sed -i -E -e 's/\s*-u\s*\w+\s*/ /' -e 's/^([\s]*OPTIONS=["]?[^"]*)("?)/\1 -u chrony\2/' /etc/sysconfig/chronyd
    else
    	echo 'OPTIONS="-u chrony"' >> /etc/sysconfig/chronyd
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - chronyd_run_as_chrony_user
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Detect if file /etc/sysconfig/chronyd is not empty or missing
      ansible.builtin.find:
        path: /etc/sysconfig/
        patterns: chronyd
        contains: ^([\s]*OPTIONS=["]?[^"]*)("?)
      register: chronyd_file
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - chronyd_run_as_chrony_user
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Remove any previous configuration of user used to run chronyd process
      ansible.builtin.replace:
        path: /etc/sysconfig/chronyd
        regexp: \s*-u\s*\w+\s*
        replace: ' '
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      - chronyd_file is defined and chronyd_file.matched > 0
      tags:
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - chronyd_run_as_chrony_user
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Correct existing line in /etc/sysconfig/chronyd to run chronyd as chrony user
      ansible.builtin.lineinfile:
        path: /etc/sysconfig/chronyd
        regexp: ^([\s]*OPTIONS=["]?[^"]*)("?)
        line: \1 -u chrony\2
        state: present
        backrefs: true
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      - chronyd_file is defined and chronyd_file.matched > 0
      tags:
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - chronyd_run_as_chrony_user
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Insert correct line into /etc/sysconfig/chronyd ensuring chronyd runs as chrony
        user
      ansible.builtin.lineinfile:
        path: /etc/sysconfig/chronyd
        line: OPTIONS="-u chrony"
        state: present
        create: true
      when:
      - '"kernel" in ansible_facts.packages'
      - '"chrony" in ansible_facts.packages'
      - chronyd_file is defined and chronyd_file.matched == 0
      tags:
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - chronyd_run_as_chrony_user
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
Group Obsolete Services Group contains 3 groups and 5 rules
[ref] This section discusses a number of network-visible services which have historically caused problems for system security, and for which disabling or severely limiting the service has been the best available guidance for some time. As a result of this, many of these services are not installed as part of Amazon Linux 2023 by default. Organizations which are running these services should switch to more secure equivalents as soon as possible. If it remains absolutely necessary to run one of these services for legacy reasons, care should be taken to restrict the service as much as possible, for instance by configuring host firewall software such as `iptables` to restrict access to the vulnerable service to only those remote hosts which have a known need to use it.
Group Rlogin, Rsh, and Rexec Group contains 1 rule
[ref] The Berkeley r-commands are legacy services which allow cleartext remote access and have an insecure trust model.
#### Rule Remove Rsh Trust Files [ref]
The files `/etc/hosts.equiv` and `~/.rhosts` (in each user's home directory) list remote hosts and users that are trusted by the local system when using the rshd daemon. To remove these files, run the following command to delete them from any location:
    $ sudo rm /etc/hosts.equiv
    $ rm ~/.rhosts
Rationale: | This action is only meaningful if `.rhosts` support is permitted through PAM. Trust files are convenient, but when used in conjunction with the R-services, they can allow unauthenticated access to a system.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_no_rsh_trust_files
References: |
cis-csc | 11, 12, 14, 15, 3, 8, 9
cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06
hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4
cis | 6.2.11
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q rsh-server; then

    find /root -xdev -type f -name ".rhosts" -exec rm -f {} \;
    find /home -maxdepth 2 -xdev -type f -name ".rhosts" -exec rm -f {} \;
    rm -f /etc/hosts.equiv

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - no_rsh_trust_files
      - restrict_strategy

    - name: Detect .rhosts files in users home directories
      ansible.builtin.find:
        paths:
        - /root
        - /home
        recurse: true
        patterns: .rhosts
        hidden: true
        file_type: file
      check_mode: false
      register: rhosts_locations
      when: '"rsh-server" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - no_rsh_trust_files
      - restrict_strategy

    - name: Remove .rhosts files
      ansible.builtin.file:
        path: '{{ item }}'
        state: absent
      with_items: '{{ rhosts_locations.files | map(attribute=''path'') | list }}'
      when:
      - '"rsh-server" in ansible_facts.packages'
      - rhosts_locations is success
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - no_rsh_trust_files
      - restrict_strategy

    - name: Remove /etc/hosts.equiv file
      ansible.builtin.file:
        path: /etc/hosts.equiv
        state: absent
      when: '"rsh-server" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - no_rsh_trust_files
      - restrict_strategy
Group Telnet Group contains 2 rules
[ref] The telnet protocol does not provide confidentiality or integrity for information transmitted on the network. This includes authentication information such as passwords. Organizations which use telnet should be actively working to migrate to a more secure protocol.
#### Rule Uninstall telnet-server Package [ref]
The `telnet-server` package can be removed with the following command:
    $ sudo dnf remove telnet-server
Rationale: | It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities are often overlooked and therefore may remain insecure. They increase the risk to the platform by providing additional attack vectors. The telnet service provides an unencrypted remote access service which does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to login using this service, the privileged user password could be compromised. Removing the `telnet-server` package decreases the risk of the telnet service's accidental (or intentional) activation.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_package_telnet-server_removed
References: |
cis-csc | 11, 12, 14, 15, 3, 8, 9
cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06
hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4
pcidss | Req-2.2.2
os-srg | SRG-OS-000095-GPOS-00049
anssi | R62
cis | 2.2.13
ism | 1409
pcidss4 | 2.2.4, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove telnet-server
    # from the system, and may remove any packages
    # that depend on telnet-server. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "telnet-server" ; then
    dnf remove -y --noautoremove "telnet-server"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=telnet-server
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall telnet-server Package: Ensure telnet-server is removed'
      ansible.builtin.package:
        name: telnet-server
        state: absent
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.2
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.4
      - disable_strategy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_telnet-server_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_telnet-server

    class remove_telnet-server {
      package { 'telnet-server':
        ensure => 'purged',
      }
    }
#### Rule Remove telnet Clients [ref]
The telnet client allows users to start connections to other systems via the telnet protocol.
Rationale: | The `telnet` protocol is insecure and unencrypted. The use of an unencrypted transmission medium could allow an unauthorized user to steal credentials. The `ssh` package provides an encrypted session and stronger security and is included in Amazon Linux 2023.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_package_telnet_removed
References: |
cui | 3.1.13
hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
iso27001-2013 | A.8.2.3, A.13.1.1, A.13.2.1, A.13.2.3, A.14.1.2, A.14.1.3
anssi | R62
cis | 2.3.1
ism | 1409
pcidss4 | 2.2.4, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove telnet
    # from the system, and may remove any packages
    # that depend on telnet. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "telnet" ; then
    dnf remove -y --noautoremove "telnet"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=telnet
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Remove telnet Clients: Ensure telnet is removed'
      ansible.builtin.package:
        name: telnet
        state: absent
      tags:
      - NIST-800-171-3.1.13
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.4
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - package_telnet_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_telnet

    class remove_telnet {
      package { 'telnet':
        ensure => 'purged',
      }
    }
Group TFTP Server Group contains 1 rule
[ref] TFTP is a lightweight version of the FTP protocol which has traditionally been used to configure networking equipment. However, TFTP provides little security, and modern versions of networking operating systems frequently support configuration via SSH or other more secure protocols. A TFTP server should be run only if no more secure method of supporting existing equipment can be found.
#### Rule Uninstall tftp-server Package [ref]
The `tftp-server` package can be removed with the following command:
     $ sudo dnf remove tftp-server
Rationale: | Removing the `tftp-server` package decreases the risk of the accidental (or intentional) activation of tftp services. If TFTP is required for operational support (such as transmission of router configurations), its use must be documented with the Information Systems Security Manager (ISSM), restricted to only authorized personnel, and have access control rules established.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_package_tftp-server_removed
References: |
cis-csc | 11, 12, 14, 15, 3, 8, 9
cobit5 | APO13.01, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS01.04, DSS05.02, DSS05.03, DSS05.05, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.2.1, A.6.2.2, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.AC-3, PR.IP-1, PR.PT-3, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R62
cis | 2.2.7
pcidss4 | 2.2.4, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove tftp-server
    # from the system, and may remove any packages
    # that depend on tftp-server. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "tftp-server" ; then
    dnf remove -y --noautoremove "tftp-server"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=tftp-server
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall tftp-server Package: Ensure tftp-server is removed'
      ansible.builtin.package:
        name: tftp-server
        state: absent
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.4
      - disable_strategy
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_tftp-server_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_tftp-server

    class remove_tftp-server {
      package { 'tftp-server':
        ensure => 'purged',
      }
    }
#### Rule Uninstall rsync Package [ref]
The rsyncd service can be used to synchronize files between systems over network links. The `rsync` package can be removed with the following command:
    $ sudo dnf remove rsync
Rationale: | The rsyncd service presents a security risk as it uses unencrypted protocols for communication.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_package_rsync_removed
References: |
cis | 2.2.18
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove rsync
    # from the system, and may remove any packages
    # that depend on rsync. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "rsync" ; then
    dnf remove -y --noautoremove "rsync"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=rsync
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall rsync Package: Ensure rsync is removed'
      ansible.builtin.package:
        name: rsync
        state: absent
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_rsync_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_rsync

    class remove_rsync {
      package { 'rsync':
        ensure => 'purged',
      }
    }
Group Print Support Group contains 1 rule
[ref] The Common Unix Printing System (CUPS) service provides both local and network printing support. A system running the CUPS service can accept print jobs from other systems, process them, and send them to the appropriate printer. It also provides an interface for remote administration through a web browser. The CUPS service is installed and activated by default. The project homepage and more detailed documentation are available at http://www.cups.org.
#### Rule Uninstall CUPS Package [ref]
The `cups` package can be removed with the following command:
    $ sudo dnf remove cups
Rationale: | If the system does not need to print jobs or accept print jobs from other systems, it is recommended that CUPS be removed to reduce the potential attack surface.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_package_cups_removed
References: |
cis-csc | 11, 14, 3, 9
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.05, DSS06.06
isa-62443-2009 | 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.9.1.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1, PR.PT-3
cis | 2.2.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove cups
    # from the system, and may remove any packages
    # that depend on cups. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "cups" ; then
    dnf remove -y --noautoremove "cups"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=cups
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall CUPS Package: Ensure cups is removed'
      ansible.builtin.package:
        name: cups
        state: absent
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_cups_removed
      - unknown_severity
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_cups

    class remove_cups {
      package { 'cups':
        ensure => 'purged',
      }
    }
Group Proxy Server Group contains 1 group and 1 rule
[ref] A proxy server is a very desirable target for a potential adversary because much (or all) sensitive data for a given infrastructure may flow through it. Therefore, if one is required, the system acting as a proxy server should be dedicated to that purpose alone and be stored in a physically secure location. The system's default proxy server software is Squid, and provided in an RPM package of the same name.
Group Disable Squid if Possible Group contains 1 rule
[ref] If Squid was installed and activated, but the system does not need to act as a proxy server, then it should be disabled and removed.
#### Rule Uninstall squid Package [ref]
The `squid` package can be removed with the following command:
     $ sudo dnf remove squid
Rationale: | If there is no need to make the proxy server software available, removing it provides a safeguard against its activation.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_package_squid_removed
References: |
cis | 2.2.11
ism | 1409
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove squid
    # from the system, and may remove any packages
    # that depend on squid. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "squid" ; then
    dnf remove -y --noautoremove "squid"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=squid
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall squid Package: Ensure squid is removed'
      ansible.builtin.package:
        name: squid
        state: absent
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_squid_removed
      - unknown_severity
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_squid

    class remove_squid {
      package { 'squid':
        ensure => 'purged',
      }
    }
Group Samba(SMB) Microsoft Windows File Sharing Server Group contains 1 group and 1 rule
[ref] When properly configured, the Samba service allows Linux systems to provide file and print sharing to Microsoft Windows systems. There are two software packages that provide Samba support. The first, `samba-client`, provides a series of command line tools that enable a client system to access Samba shares. The second, simply labeled `samba`, provides the Samba service. It is this second package that allows a Linux system to act as an Active Directory server, a domain controller, or as a domain member. Only the `samba-client` package is installed by default.
Group Disable Samba if Possible Group contains 1 rule
[ref] Even after the Samba server package has been installed, it will remain disabled. Do not enable this service unless it is absolutely necessary to provide Microsoft Windows file and print sharing functionality.
#### Rule Uninstall Samba Package [ref]
The `samba` package can be removed with the following command:
     $ sudo dnf remove samba
Rationale: | If there is no need to make the Samba software available, removing it provides a safeguard against its activation.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_package_samba_removed
References: |
cis | 2.2.10
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove samba
    # from the system, and may remove any packages
    # that depend on samba. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "samba" ; then
    dnf remove -y --noautoremove "samba"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=samba
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall Samba Package: Ensure samba is removed'
      ansible.builtin.package:
        name: samba
        state: absent
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_samba_removed
      - unknown_severity
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_samba

    class remove_samba {
      package { 'samba':
        ensure => 'purged',
      }
    }
Group SNMP Server Group contains 1 group and 2 rules
[ref] The Simple Network Management Protocol allows administrators to monitor the state of network devices, including computers. Older versions of SNMP were well-known for weak security, such as plaintext transmission of the community string (used for authentication) and usage of easily-guessable choices for the community string.
Group Disable SNMP Server if Possible Group contains 2 rules
[ref] The system includes an SNMP daemon that allows for its remote monitoring, though it not installed by default. If it was installed and activated but is not needed, the software should be disabled and removed.
#### Rule Uninstall net-snmp Package [ref]
The `net-snmp` package provides the snmpd service. The `net-snmp` package can be removed with the following command:
    $ sudo dnf remove net-snmp
Rationale: | If there is no need to run SNMP server software, removing the package provides a safeguard against its activation.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_package_net-snmp_removed
References: |
cis | 2.2.12
pcidss4 | 2.2.4, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove net-snmp
    # from the system, and may remove any packages
    # that depend on net-snmp. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "net-snmp" ; then
    dnf remove -y --noautoremove "net-snmp"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=net-snmp
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Uninstall net-snmp Package: Ensure net-snmp is removed'
      ansible.builtin.package:
        name: net-snmp
        state: absent
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.4
      - disable_strategy
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - package_net-snmp_removed
      - unknown_severity
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_net-snmp

    class remove_net-snmp {
      package { 'net-snmp':
        ensure => 'purged',
      }
    }
#### Rule Disable snmpd Service [ref]
The `snmpd` service can be disabled with the following command:
    $ sudo systemctl mask --now snmpd.service
Rationale: | Running SNMP software provides a network-based avenue of attack, and should be disabled if not needed.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_service_snmpd_disabled
References: |
cis | 2.2.12
ism | 1311
Remediation OSBuild Blueprint snippet ⇲
    [customizations.services]
    masked = ["snmpd"]
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # Remediation is applicable only in certain platforms
    if ( ( rpm --quiet -q net-snmp && rpm --quiet -q kernel ) ); then

    SYSTEMCTL_EXEC='/usr/bin/systemctl'
    if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
      "$SYSTEMCTL_EXEC" stop 'snmpd.service'
    fi
    "$SYSTEMCTL_EXEC" disable 'snmpd.service'
    "$SYSTEMCTL_EXEC" mask 'snmpd.service'
    # Disable socket activation if we have a unit file for it
    if "$SYSTEMCTL_EXEC" -q list-unit-files snmpd.socket; then
        if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
          "$SYSTEMCTL_EXEC" stop 'snmpd.socket'
        fi
        "$SYSTEMCTL_EXEC" mask 'snmpd.socket'
    fi
    # The service may not be running because it has been started and failed,
    # so let's reset the state so OVAL checks pass.
    # Service should be 'inactive', not 'failed' after reboot though.
    "$SYSTEMCTL_EXEC" reset-failed 'snmpd.service' || true

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - service_snmpd_disabled

    - name: Disable snmpd Service - Disable service snmpd
      block:

      - name: Disable snmpd Service - Collect systemd Services Present in the System
        ansible.builtin.command: systemctl -q list-unit-files --type service
        register: service_exists
        changed_when: false
        failed_when: service_exists.rc not in [0, 1]
        check_mode: false

      - name: Disable snmpd Service - Ensure snmpd.service is Masked
        ansible.builtin.systemd:
          name: snmpd.service
          state: stopped
          enabled: false
          masked: true
        when: service_exists.stdout_lines is search("snmpd.service", multiline=True)

      - name: Unit Socket Exists - snmpd.socket
        ansible.builtin.command: systemctl -q list-unit-files snmpd.socket
        register: socket_file_exists
        changed_when: false
        failed_when: socket_file_exists.rc not in [0, 1]
        check_mode: false

      - name: Disable snmpd Service - Disable Socket snmpd
        ansible.builtin.systemd:
          name: snmpd.socket
          enabled: false
          state: stopped
          masked: true
        when: socket_file_exists.stdout_lines is search("snmpd.socket", multiline=True)
      tags:
      - disable_strategy
      - low_complexity
      - low_disruption
      - low_severity
      - no_reboot_needed
      - service_snmpd_disabled
      - special_service_block
      when: ( "net-snmp" in ansible_facts.packages and "kernel" in ansible_facts.packages
        )
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include disable_snmpd

    class disable_snmpd {
      service {'snmpd':
        enable => false,
        ensure => 'stopped',
      }
    }
Group SSH Server Group contains 1 group and 26 rules
[ref] The SSH protocol is recommended for remote login and remote file transfer. SSH provides confidentiality and integrity for data exchanged between two systems, as well as server authentication, through the use of public key cryptography. The implementation included with the system is called OpenSSH, and more detailed documentation is available from its website, https://www.openssh.com. Its server program is called `sshd` and provided by the RPM package `openssh-server`.
Group Configure OpenSSH Server if Necessary Group contains 17 rules
[ref] If the system needs to act as an SSH server, then certain changes should be made to the OpenSSH daemon configuration file `/etc/ssh/sshd_config`. The following recommendations can be applied to this file. See the `sshd_config(5)` man page for more detailed information.
#### Rule Set SSH Client Alive Count Max [ref]
The SSH server sends at most `ClientAliveCountMax` messages during a SSH session and waits for a response from the SSH client. The option `ClientAliveInterval` configures timeout after each `ClientAliveCountMax` message. If the SSH server does not receive a response from the client, then the connection is considered unresponsive and terminated. For SSH earlier than v8.2, a `ClientAliveCountMax` value of `0` causes a timeout precisely when the `ClientAliveInterval` is set. Starting with v8.2, a value of `0` disables the timeout functionality completely. If the option is set to a number greater than `0`, then the session will be disconnected after `ClientAliveInterval * ClientAliveCountMax` seconds without receiving a keep alive message.
Rationale: | This ensures a user login will be terminated as soon as the `ClientAliveInterval` is reached.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_set_keepalive
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8
cjis | 5.5.6
cobit5 | APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.1.11
hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2
iso27001-2013 | A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nerc-cip | CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nist | AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a)
nist-csf | DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2
pcidss | Req-8.1.8
os-srg | SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109
cis | 4.2.20
pcidss4 | 8.2.8, 8.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    var_sshd_set_keepalive='1'

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    chmod 0600 /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

    LC_ALL=C sed -i "/^\s*ClientAliveCountMax\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*ClientAliveCountMax\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then

        LC_ALL=C sed -i "/^\s*ClientAliveCountMax\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    else
        touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

    cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "ClientAliveCountMax $var_sshd_set_keepalive" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    cat "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSS-Req-8.1.8
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.8
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_keepalive
    - name: XCCDF Value var_sshd_set_keepalive # promote to variable
      set_fact:
        var_sshd_set_keepalive: !!str 1
      tags:
        - always

    - name: Set SSH Client Alive Count Max - Check if the parameter ClientAliveCountMax
        is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "ClientAliveCountMax"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSS-Req-8.1.8
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.8
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_keepalive

    - name: Set SSH Client Alive Count Max - Check if the parameter ClientAliveCountMax
        is configured correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "ClientAliveCountMax"| regex_escape }}\s+{{ var_sshd_set_keepalive
          }}$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSS-Req-8.1.8
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.8
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_keepalive

    - name: Set SSH Client Alive Count Max
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "ClientAliveCountMax"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter ClientAliveCountMax is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "ClientAliveCountMax"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "ClientAliveCountMax"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "ClientAliveCountMax"| regex_escape }}\s+
          line: ClientAliveCountMax {{ var_sshd_set_keepalive }}
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSS-Req-8.1.8
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.8
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_keepalive

    - name: Set SSH Client Alive Count Max - set file mode for /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSS-Req-8.1.8
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.8
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_keepalive
#### Rule Set SSH Client Alive Interval [ref]
SSH allows administrators to set a network responsiveness timeout interval. After this interval has passed, the unresponsive client will be automatically logged out. To set this timeout interval, edit the following line in `/etc/ssh/sshd_config` as follows:
    ClientAliveInterval 900
The timeout interval is given in seconds. For example, have a timeout of 10 minutes, set interval to 600. If a shorter timeout has already been set for the login shell, that value will preempt any SSH setting made in `/etc/ssh/sshd_config`. Keep in mind that some processes may stop SSH from correctly detecting that the user is idle. Warning: SSH disconnecting unresponsive clients will not have desired effect without also configuring ClientAliveCountMax in the SSH service configuration. Warning: Following conditions may prevent the SSH session to time out: Remote processes on the remote machine generates output. As the output has to be transferred over the network to the client, the timeout is reset every time such transfer happens. Any `scp` or `sftp` activity by the same user to the host resets the timeout.
Rationale: | Terminating an idle ssh session within a short time period reduces the window of opportunity for unauthorized personnel to take control of a management session enabled on the console or console port that has been let unattended.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_set_idle_timeout
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 18, 3, 5, 7, 8
cjis | 5.5.6
cobit5 | APO13.01, BAI03.01, BAI03.02, BAI03.03, DSS01.03, DSS03.05, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.03, DSS06.10
cui | 3.1.11
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 6.2
iso27001-2013 | A.12.4.1, A.12.4.3, A.14.1.1, A.14.2.1, A.14.2.5, A.18.1.4, A.6.1.2, A.6.1.5, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nerc-cip | CIP-004-6 R2.2.3, CIP-007-3 R5.1, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nist | CM-6(a), AC-17(a), AC-2(5), AC-12, AC-17(a), SC-10, CM-6(a)
nist-csf | DE.CM-1, DE.CM-3, PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.IP-2
pcidss | Req-8.1.8
os-srg | SRG-OS-000126-GPOS-00066, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109, SRG-OS-000395-GPOS-00175
cis | 4.2.20
pcidss4 | 8.2.8, 8.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    sshd_idle_timeout_value='900'

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    chmod 0600 /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

    LC_ALL=C sed -i "/^\s*ClientAliveInterval\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*ClientAliveInterval\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then

        LC_ALL=C sed -i "/^\s*ClientAliveInterval\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    else
        touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

    cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "ClientAliveInterval $sshd_idle_timeout_value" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    cat "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSS-Req-8.1.8
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.8
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_idle_timeout
    - name: XCCDF Value sshd_idle_timeout_value # promote to variable
      set_fact:
        sshd_idle_timeout_value: !!str 900
      tags:
        - always

    - name: Set SSH Client Alive Interval - Check if the parameter ClientAliveInterval
        is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "ClientAliveInterval"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSS-Req-8.1.8
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.8
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_idle_timeout

    - name: Set SSH Client Alive Interval - Check if the parameter ClientAliveInterval
        is configured correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "ClientAliveInterval"| regex_escape }}\s+{{ sshd_idle_timeout_value
          }}$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSS-Req-8.1.8
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.8
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_idle_timeout

    - name: Set SSH Client Alive Interval
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "ClientAliveInterval"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter ClientAliveInterval is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "ClientAliveInterval"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "ClientAliveInterval"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "ClientAliveInterval"| regex_escape }}\s+
          line: ClientAliveInterval {{ sshd_idle_timeout_value }}
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSS-Req-8.1.8
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.8
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_idle_timeout

    - name: Set SSH Client Alive Interval - set file mode for /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.11
      - NIST-800-53-AC-12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-2(5)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SC-10
      - PCI-DSS-Req-8.1.8
      - PCI-DSSv4-8.2
      - PCI-DSSv4-8.2.8
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_idle_timeout
#### Rule Disable Host-Based Authentication [ref]
SSH's cryptographic host-based authentication is more secure than `.rhosts` authentication. However, it is not recommended that hosts unilaterally trust one another, even within an organization. The default SSH configuration disables host-based authentication. The appropriate configuration is used if no value is set for `HostbasedAuthentication`. To explicitly disable host-based authentication, add or correct the following line in `/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf`:
    HostbasedAuthentication no
Rationale: | SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_disable_host_auth
References: |
cis-csc | 11, 12, 14, 15, 16, 18, 3, 5, 9
cjis | 5.5.6
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06
cui | 3.1.12
hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nist | AC-3, AC-17(a), CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.AC-4, PR.AC-6, PR.IP-1, PR.PT-3
ospp | FIA_UAU.1
os-srg | SRG-OS-000480-GPOS-00229
cis | 4.2.8
ism | 0421, 0422, 0484, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561
pcidss4 | 8.3.1, 8.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    chmod 0600 /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

    LC_ALL=C sed -i "/^\s*HostbasedAuthentication\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*HostbasedAuthentication\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then

        LC_ALL=C sed -i "/^\s*HostbasedAuthentication\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    else
        touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

    cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "HostbasedAuthentication no" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    cat "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.1
      - disable_host_auth
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable Host-Based Authentication - Check if the parameter HostbasedAuthentication
        is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "HostbasedAuthentication"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.1
      - disable_host_auth
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable Host-Based Authentication - Check if the parameter HostbasedAuthentication
        is configured correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "HostbasedAuthentication"| regex_escape }}\s+no$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.1
      - disable_host_auth
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable Host-Based Authentication
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "HostbasedAuthentication"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter HostbasedAuthentication is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "HostbasedAuthentication"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "HostbasedAuthentication"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "HostbasedAuthentication"| regex_escape }}\s+
          line: HostbasedAuthentication no
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.1
      - disable_host_auth
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Disable Host-Based Authentication - set file mode for /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-8.3
      - PCI-DSSv4-8.3.1
      - disable_host_auth
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Disable SSH Access via Empty Passwords [ref]
Disallow SSH login with empty passwords. The default SSH configuration disables logins with empty passwords. The appropriate configuration is used if no value is set for `PermitEmptyPasswords`. To explicitly disallow SSH login from accounts with empty passwords, add or correct the following line in `/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf`:
    PermitEmptyPasswords no
Any accounts with empty passwords should be disabled immediately, and PAM configuration should prevent users from being able to assign themselves empty passwords.
Rationale: | Configuring this setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere.
Severity: | high
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_disable_empty_passwords
References: |
cis-csc | 11, 12, 13, 14, 15, 16, 18, 3, 5, 9
cjis | 5.5.6
cobit5 | APO01.06, BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.02, DSS06.03, DSS06.06
cui | 3.1.1, 3.1.5
hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2, SR 7.6
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.1.2, A.12.5.1, A.12.6.2, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | AC-17(a), CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.AC-4, PR.AC-6, PR.DS-5, PR.IP-1, PR.PT-3
ospp | FIA_UAU.1
pcidss | Req-2.2.4
os-srg | SRG-OS-000106-GPOS-00053, SRG-OS-000480-GPOS-00229, SRG-OS-000480-GPOS-00227
cis | 4.2.9
ism | 1546
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    chmod 0600 /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

    LC_ALL=C sed -i "/^\s*PermitEmptyPasswords\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*PermitEmptyPasswords\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then

        LC_ALL=C sed -i "/^\s*PermitEmptyPasswords\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    else
        touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

    cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "PermitEmptyPasswords no" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    cat "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_empty_passwords

    - name: Disable SSH Access via Empty Passwords - Check if the parameter PermitEmptyPasswords
        is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "PermitEmptyPasswords"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_empty_passwords

    - name: Disable SSH Access via Empty Passwords - Check if the parameter PermitEmptyPasswords
        is configured correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "PermitEmptyPasswords"| regex_escape }}\s+no$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_empty_passwords

    - name: Disable SSH Access via Empty Passwords
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "PermitEmptyPasswords"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter PermitEmptyPasswords is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "PermitEmptyPasswords"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "PermitEmptyPasswords"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "PermitEmptyPasswords"| regex_escape }}\s+
          line: PermitEmptyPasswords no
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_empty_passwords

    - name: Disable SSH Access via Empty Passwords - set file mode for /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - high_severity
      - low_complexity
      - low_disruption
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_empty_passwords
#### Rule Disable SSH Support for .rhosts Files [ref]
SSH can emulate the behavior of the obsolete rsh command in allowing users to enable insecure access to their accounts via `.rhosts` files. The default SSH configuration disables support for `.rhosts`. The appropriate configuration is used if no value is set for `IgnoreRhosts`. To explicitly disable support for .rhosts files, add or correct the following line in `/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf`:
    IgnoreRhosts yes
Rationale: | SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_disable_rhosts
References: |
cis-csc | 11, 12, 14, 15, 16, 18, 3, 5, 9
cjis | 5.5.6
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06
cui | 3.1.12
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4, A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | AC-17(a), CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.AC-4, PR.AC-6, PR.IP-1, PR.PT-3
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.2.11
ism | 1546
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    chmod 0600 /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

    LC_ALL=C sed -i "/^\s*IgnoreRhosts\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*IgnoreRhosts\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then

        LC_ALL=C sed -i "/^\s*IgnoreRhosts\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    else
        touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

    cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "IgnoreRhosts yes" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    cat "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_rhosts

    - name: Disable SSH Support for .rhosts Files - Check if the parameter IgnoreRhosts
        is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "IgnoreRhosts"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_rhosts

    - name: Disable SSH Support for .rhosts Files - Check if the parameter IgnoreRhosts
        is configured correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "IgnoreRhosts"| regex_escape }}\s+yes$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_rhosts

    - name: Disable SSH Support for .rhosts Files
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "IgnoreRhosts"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter IgnoreRhosts is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "IgnoreRhosts"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "IgnoreRhosts"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "IgnoreRhosts"| regex_escape }}\s+
          line: IgnoreRhosts yes
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_rhosts

    - name: Disable SSH Support for .rhosts Files - set file mode for /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_rhosts
#### Rule Disable SSH Root Login [ref]
The root user should never be allowed to login to a system directly over a network. To disable root login via SSH, add or correct the following line in `/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf`:
    PermitRootLogin no
Rationale: | Even though the communications channel may be encrypted, an additional layer of security is gained by extending the policy of not logging directly on as root. In addition, logging in with a user-specific account provides individual accountability of actions performed on the system and also helps to minimize direct attack attempts on root's password.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_disable_root_login
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 3, 5
cjis | 5.5.6
cobit5 | APO01.06, DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS05.10, DSS06.02, DSS06.03, DSS06.06, DSS06.10
cui | 3.1.1, 3.1.5
hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.18.1.4, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nist | AC-6(2), AC-17(a), IA-2, IA-2(5), CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.AC-1, PR.AC-4, PR.AC-6, PR.AC-7, PR.DS-5, PR.PT-3
ospp | FAU_GEN.1
pcidss | Req-2.2.4
os-srg | SRG-OS-000109-GPOS-00056, SRG-OS-000480-GPOS-00227
app-srg-ctr | SRG-APP-000148-CTR-000335, SRG-APP-000190-CTR-000500
anssi | R33
cis | 4.2.7
ism | 1546
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    chmod 0600 /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

    LC_ALL=C sed -i "/^\s*PermitRootLogin\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*PermitRootLogin\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then

        LC_ALL=C sed -i "/^\s*PermitRootLogin\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    else
        touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

    cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "PermitRootLogin no" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    cat "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(2)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-IA-2
      - NIST-800-53-IA-2(5)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_root_login

    - name: Disable SSH Root Login - Check if the parameter PermitRootLogin is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "PermitRootLogin"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(2)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-IA-2
      - NIST-800-53-IA-2(5)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_root_login

    - name: Disable SSH Root Login - Check if the parameter PermitRootLogin is configured
        correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "PermitRootLogin"| regex_escape }}\s+no$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(2)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-IA-2
      - NIST-800-53-IA-2(5)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_root_login

    - name: Disable SSH Root Login
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "PermitRootLogin"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter PermitRootLogin is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "PermitRootLogin"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "PermitRootLogin"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "PermitRootLogin"| regex_escape }}\s+
          line: PermitRootLogin no
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(2)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-IA-2
      - NIST-800-53-IA-2(5)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_root_login

    - name: Disable SSH Root Login - set file mode for /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.1
      - NIST-800-171-3.1.5
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(2)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - NIST-800-53-IA-2
      - NIST-800-53-IA-2(5)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_root_login
#### Rule Disable SSH TCP Forwarding [ref]
The `AllowTcpForwarding` parameter specifies whether TCP forwarding is permitted. To disable TCP forwarding, add or correct the following line in `/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf`:
    AllowTcpForwarding no
Rationale: | Leaving port forwarding enabled can expose the organization to security risks and back-doors.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_disable_tcp_forwarding
References: |
cis | 4.2.13
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    chmod 0600 /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

    LC_ALL=C sed -i "/^\s*AllowTcpForwarding\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*AllowTcpForwarding\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then

        LC_ALL=C sed -i "/^\s*AllowTcpForwarding\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    else
        touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

    cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "AllowTcpForwarding no" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    cat "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_tcp_forwarding

    - name: Disable SSH TCP Forwarding - Check if the parameter AllowTcpForwarding is
        configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "AllowTcpForwarding"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_tcp_forwarding

    - name: Disable SSH TCP Forwarding - Check if the parameter AllowTcpForwarding is
        configured correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "AllowTcpForwarding"| regex_escape }}\s+no$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_tcp_forwarding

    - name: Disable SSH TCP Forwarding
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "AllowTcpForwarding"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter AllowTcpForwarding is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "AllowTcpForwarding"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "AllowTcpForwarding"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "AllowTcpForwarding"| regex_escape }}\s+
          line: AllowTcpForwarding no
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_tcp_forwarding

    - name: Disable SSH TCP Forwarding - set file mode for /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_tcp_forwarding
#### Rule Disable X11 Forwarding [ref]
The X11Forwarding parameter provides the ability to tunnel X11 traffic through the connection to enable remote graphic connections. SSH has the capability to encrypt remote X11 connections when SSH's `X11Forwarding` option is enabled. The default SSH configuration disables X11Forwarding. The appropriate configuration is used if no value is set for `X11Forwarding`. To explicitly disable X11 Forwarding, add or correct the following line in `/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf`:
    X11Forwarding no
Rationale: | Disable X11 forwarding unless there is an operational requirement to use X11 applications directly. There is a small risk that the remote X11 servers of users who are logged in via SSH with X11 forwarding could be compromised by other users on the X11 server. Note that even if X11 forwarding is disabled, users can always install their own forwarders.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_disable_x11_forwarding
References: |
nist | CM-6(b)
os-srg | SRG-OS-000480-GPOS-00227
cis | 4.2.12
ism | 0484
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    chmod 0600 /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

    LC_ALL=C sed -i "/^\s*X11Forwarding\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*X11Forwarding\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then

        LC_ALL=C sed -i "/^\s*X11Forwarding\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    else
        touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

    cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "X11Forwarding no" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    cat "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(b)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_x11_forwarding

    - name: Disable X11 Forwarding - Check if the parameter X11Forwarding is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "X11Forwarding"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(b)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_x11_forwarding

    - name: Disable X11 Forwarding - Check if the parameter X11Forwarding is configured
        correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "X11Forwarding"| regex_escape }}\s+no$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(b)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_x11_forwarding

    - name: Disable X11 Forwarding
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "X11Forwarding"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter X11Forwarding is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "X11Forwarding"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "X11Forwarding"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "X11Forwarding"| regex_escape }}\s+
          line: X11Forwarding no
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - NIST-800-53-CM-6(b)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_x11_forwarding

    - name: Disable X11 Forwarding - set file mode for /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(b)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_disable_x11_forwarding
#### Rule Do Not Allow SSH Environment Options [ref]
Ensure that users are not able to override environment variables of the SSH daemon. The default SSH configuration disables environment processing. The appropriate configuration is used if no value is set for `PermitUserEnvironment`. To explicitly disable Environment options, add or correct the following `/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf`:
    PermitUserEnvironment no
Rationale: | SSH environment options potentially allow users to bypass access restriction in some configurations.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_do_not_permit_user_env
References: |
cis-csc | 11, 3, 9
cjis | 5.5.6
cobit5 | BAI10.01, BAI10.02, BAI10.03, BAI10.05
cui | 3.1.12
hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-2009 | 4.3.4.3.2, 4.3.4.3.3
isa-62443-2013 | SR 7.6
iso27001-2013 | A.12.1.2, A.12.5.1, A.12.6.2, A.14.2.2, A.14.2.3, A.14.2.4
nist | AC-17(a), CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.IP-1
pcidss | Req-2.2.4
os-srg | SRG-OS-000480-GPOS-00229
cis | 4.2.10
ism | 1546
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
    chmod 0600 /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf

    LC_ALL=C sed -i "/^\s*PermitUserEnvironment\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*PermitUserEnvironment\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" ] ; then

        LC_ALL=C sed -i "/^\s*PermitUserEnvironment\s\+/Id" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    else
        touch "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"

    cp "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf" "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "PermitUserEnvironment no" > "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    cat "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak" >> "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_do_not_permit_user_env

    - name: Do Not Allow SSH Environment Options - Check if the parameter PermitUserEnvironment
        is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "PermitUserEnvironment"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_do_not_permit_user_env

    - name: Do Not Allow SSH Environment Options - Check if the parameter PermitUserEnvironment
        is configured correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "PermitUserEnvironment"| regex_escape }}\s+no$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_do_not_permit_user_env

    - name: Do Not Allow SSH Environment Options
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "PermitUserEnvironment"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter PermitUserEnvironment is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "PermitUserEnvironment"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "PermitUserEnvironment"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "PermitUserEnvironment"| regex_escape }}\s+
          line: PermitUserEnvironment no
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_do_not_permit_user_env

    - name: Do Not Allow SSH Environment Options - set file mode for /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/01-complianceascode-reinforce-os-defaults.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.12
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_do_not_permit_user_env
#### Rule Enable PAM [ref]
UsePAM Enables the Pluggable Authentication Module interface. If set to “yes” this will enable PAM authentication using ChallengeResponseAuthentication and PasswordAuthentication in addition to PAM account and session module processing for all authentication types. To enable PAM authentication, add or correct the following line in `/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf`:
    UsePAM yes
Rationale: | When UsePAM is set to yes, PAM runs through account and session types properly. This is important if you want to restrict access to services based off of IP, time or other factors of the account. Additionally, you can make sure users inherit certain environment variables on login or disallow access to the server.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_enable_pam
References: |
os-srg | SRG-OS-000125-GPOS-00065
cis | 4.2.6
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    chmod 0600 /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

    LC_ALL=C sed -i "/^\s*UsePAM\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*UsePAM\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then

        LC_ALL=C sed -i "/^\s*UsePAM\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    else
        touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

    cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "UsePAM yes" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    cat "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_enable_pam

    - name: Enable PAM - Check if the parameter UsePAM is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "UsePAM"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_enable_pam

    - name: Enable PAM - Check if the parameter UsePAM is configured correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "UsePAM"| regex_escape }}\s+yes$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_enable_pam

    - name: Enable PAM
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "UsePAM"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter UsePAM is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "UsePAM"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "UsePAM"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "UsePAM"| regex_escape }}\s+
          line: UsePAM yes
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_enable_pam

    - name: Enable PAM - set file mode for /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_enable_pam
#### Rule Enable SSH Warning Banner [ref]
To enable the warning banner and ensure it is consistent across the system, add or correct the following line in `/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf`:
    Banner /etc/issue.net
Another section contains information on how to create an appropriate system-wide warning banner.
Rationale: | The warning message reinforces policy awareness during the logon process and facilitates possible legal action against attackers. Alternatively, systems whose ownership should not be obvious should ensure usage of a banner that does not provide easy attribution.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_enable_warning_banner_net
References: |
cjis | 5.5.6
cobit5 | DSS05.04, DSS05.10, DSS06.10
cui | 3.1.9
hipaa | 164.308(a)(4)(i), 164.308(b)(1), 164.308(b)(3), 164.310(b), 164.312(e)(1), 164.312(e)(2)(ii)
isa-62443-2009 | 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.2, SR 1.5, SR 1.7, SR 1.8, SR 1.9
iso27001-2013 | A.18.1.4, A.9.2.1, A.9.2.4, A.9.3.1, A.9.4.2, A.9.4.3
nist | AC-8(a), AC-8(c), AC-17(a), CM-6(a)
nist-csf | PR.AC-7
os-srg | SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088
cis | 4.2.15
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    chmod 0600 /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

    LC_ALL=C sed -i "/^\s*Banner\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*Banner\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then

        LC_ALL=C sed -i "/^\s*Banner\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    else
        touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

    cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "Banner /etc/issue.net" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    cat "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.9
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-8(a)
      - NIST-800-53-AC-8(c)
      - NIST-800-53-CM-6(a)
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_enable_warning_banner_net

    - name: Enable SSH Warning Banner - Check if the parameter Banner is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "Banner"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.9
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-8(a)
      - NIST-800-53-AC-8(c)
      - NIST-800-53-CM-6(a)
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_enable_warning_banner_net

    - name: Enable SSH Warning Banner - Check if the parameter Banner is configured correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "Banner"| regex_escape }}\s+/etc/issue.net$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.9
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-8(a)
      - NIST-800-53-AC-8(c)
      - NIST-800-53-CM-6(a)
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_enable_warning_banner_net

    - name: Enable SSH Warning Banner
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "Banner"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter Banner is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "Banner"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "Banner"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "Banner"| regex_escape }}\s+
          line: Banner /etc/issue.net
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.9
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-8(a)
      - NIST-800-53-AC-8(c)
      - NIST-800-53-CM-6(a)
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_enable_warning_banner_net

    - name: Enable SSH Warning Banner - set file mode for /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.5.6
      - NIST-800-171-3.1.9
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-8(a)
      - NIST-800-53-AC-8(c)
      - NIST-800-53-CM-6(a)
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_enable_warning_banner_net
#### Rule Limit Users' SSH Access [ref]
By default, the SSH configuration allows any user with an account to access the system. There are several options available to limit which users and group can access the system via SSH. It is recommended that at least one of the following options be leveraged: - AllowUsers variable gives the system administrator the option of allowing specific users to ssh into the system. The list consists of space separated user names. Numeric user IDs are not recognized with this variable. If a system administrator wants to restrict user access further by specifically allowing a user's access only from a particular host, the entry can be specified in the form of user@host. - AllowGroups variable gives the system administrator the option of allowing specific groups of users to ssh into the system. The list consists of space separated group names. Numeric group IDs are not recognized with this variable. - DenyUsers variable gives the system administrator the option of denying specific users to ssh into the system. The list consists of space separated user names. Numeric user IDs are not recognized with this variable. If a system administrator wants to restrict user access further by specifically denying a user's access from a particular host, the entry can be specified in the form of user@host. - DenyGroups variable gives the system administrator the option of denying specific groups of users to ssh into the system. The list consists of space separated group names. Numeric group IDs are not recognized with this variable. Warning: Automated remediation is not available for this configuration check because each system has unique user names and group names.
Rationale: | Specifying which accounts are allowed SSH access into the system reduces the possibility of unauthorized access to the system.
Severity: | unknown
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_limit_user_access
References: |
cis-csc | 11, 12, 14, 15, 16, 18, 3, 5
cobit5 | DSS05.02, DSS05.04, DSS05.05, DSS05.07, DSS06.03, DSS06.06
cui | 3.1.12
isa-62443-2009 | 4.3.3.2.2, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.3, 4.3.3.5.4, 4.3.3.5.5, 4.3.3.5.6, 4.3.3.5.7, 4.3.3.5.8, 4.3.3.6.1, 4.3.3.6.2, 4.3.3.6.3, 4.3.3.6.4, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.3.6.9, 4.3.3.7.1, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4
isa-62443-2013 | SR 1.1, SR 1.10, SR 1.11, SR 1.12, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.6, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.2, SR 2.3, SR 2.4, SR 2.5, SR 2.6, SR 2.7
iso27001-2013 | A.6.1.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nist | AC-3, CM-6(a)
nist-csf | PR.AC-4, PR.AC-6, PR.PT-3
pcidss | Req-2.2.4
cis | 4.2.4
pcidss4 | 2.2.6, 2.2
#### Rule Ensure SSH LoginGraceTime is configured [ref]
The `LoginGraceTime` parameter to the SSH server specifies the time allowed for successful authentication to the SSH server. The longer the Grace period is the more open unauthenticated connections can exist. Like other session controls in this session the Grace Period should be limited to appropriate limits to ensure the service is available for needed access.
Rationale: | Setting the `LoginGraceTime` parameter to a low number will minimize the risk of successful brute force attacks to the SSH server. It will also limit the number of concurrent unauthenticated connections.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_set_login_grace_time
References: |
cis | 4.2.19
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    var_sshd_set_login_grace_time='60'

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    chmod 0600 /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

    LC_ALL=C sed -i "/^\s*LoginGraceTime\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*LoginGraceTime\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then

        LC_ALL=C sed -i "/^\s*LoginGraceTime\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    else
        touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

    cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "LoginGraceTime $var_sshd_set_login_grace_time" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    cat "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_login_grace_time
    - name: XCCDF Value var_sshd_set_login_grace_time # promote to variable
      set_fact:
        var_sshd_set_login_grace_time: !!str 60
      tags:
        - always

    - name: Ensure SSH LoginGraceTime is configured - Check if the parameter LoginGraceTime
        is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "LoginGraceTime"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_login_grace_time

    - name: Ensure SSH LoginGraceTime is configured - Check if the parameter LoginGraceTime
        is configured correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "LoginGraceTime"| regex_escape }}\s+{{ var_sshd_set_login_grace_time
          }}$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_login_grace_time

    - name: Ensure SSH LoginGraceTime is configured
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "LoginGraceTime"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter LoginGraceTime is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "LoginGraceTime"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "LoginGraceTime"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "LoginGraceTime"| regex_escape }}\s+
          line: LoginGraceTime {{ var_sshd_set_login_grace_time }}
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_login_grace_time

    - name: Ensure SSH LoginGraceTime is configured - set file mode for /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_login_grace_time
#### Rule Set SSH Daemon LogLevel to VERBOSE [ref]
The `VERBOSE` parameter configures the SSH daemon to record login and logout activity. To specify the log level in SSH, add or correct the following line in `/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf`:
    LogLevel VERBOSE
Rationale: | SSH provides several logging levels with varying amounts of verbosity. `DEBUG` is specifically not recommended other than strictly for debugging SSH communications since it provides so much data that it is difficult to identify important security information. `INFO` or `VERBOSE` level is the basic level that only records login activity of SSH users. In many situations, such as Incident Response, it is important to determine when a particular user was active on a system. The logout record can eliminate those users who disconnected, which helps narrow the field.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_set_loglevel_verbose
References: |
nerc-cip | CIP-007-3 R7.1
nist | AC-17(a), AC-17(1), CM-6(a)
pcidss | Req-2.2.4
os-srg | SRG-OS-000032-GPOS-00013
cis | 4.2.5
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    chmod 0600 /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

    LC_ALL=C sed -i "/^\s*LogLevel\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*LogLevel\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then

        LC_ALL=C sed -i "/^\s*LogLevel\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    else
        touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

    cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "LogLevel VERBOSE" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    cat "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-17(1)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_loglevel_verbose

    - name: Set SSH Daemon LogLevel to VERBOSE - Check if the parameter LogLevel is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "LogLevel"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-17(1)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_loglevel_verbose

    - name: Set SSH Daemon LogLevel to VERBOSE - Check if the parameter LogLevel is configured
        correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "LogLevel"| regex_escape }}\s+VERBOSE$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-17(1)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_loglevel_verbose

    - name: Set SSH Daemon LogLevel to VERBOSE
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "LogLevel"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter LogLevel is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "LogLevel"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "LogLevel"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "LogLevel"| regex_escape }}\s+
          line: LogLevel VERBOSE
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - NIST-800-53-AC-17(1)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_loglevel_verbose

    - name: Set SSH Daemon LogLevel to VERBOSE - set file mode for /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-17(1)
      - NIST-800-53-AC-17(a)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_loglevel_verbose
#### Rule Set SSH authentication attempt limit [ref]
The `MaxAuthTries` parameter specifies the maximum number of authentication attempts permitted per connection. Once the number of failures reaches half this value, additional failures are logged. to set MaxAUthTries edit `/etc/ssh/sshd_config` as follows:
    MaxAuthTries 4
Rationale: | Setting the MaxAuthTries parameter to a low number will minimize the risk of successful brute force attacks to the SSH server.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_set_max_auth_tries
References: |
cis | 4.2.16
ism | 0421, 0422, 0974, 1173, 1401, 1504, 1505, 1546, 1557, 1558, 1559, 1560, 1561
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    sshd_max_auth_tries_value='4'

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    chmod 0600 /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

    LC_ALL=C sed -i "/^\s*MaxAuthTries\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*MaxAuthTries\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then

        LC_ALL=C sed -i "/^\s*MaxAuthTries\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    else
        touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

    cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "MaxAuthTries $sshd_max_auth_tries_value" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    cat "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_max_auth_tries
    - name: XCCDF Value sshd_max_auth_tries_value # promote to variable
      set_fact:
        sshd_max_auth_tries_value: !!str 4
      tags:
        - always

    - name: Set SSH authentication attempt limit - Check if the parameter MaxAuthTries
        is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "MaxAuthTries"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_max_auth_tries

    - name: Set SSH authentication attempt limit - Check if the parameter MaxAuthTries
        is configured correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "MaxAuthTries"| regex_escape }}\s+{{ sshd_max_auth_tries_value
          }}$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_max_auth_tries

    - name: Set SSH authentication attempt limit
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "MaxAuthTries"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter MaxAuthTries is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "MaxAuthTries"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "MaxAuthTries"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "MaxAuthTries"| regex_escape }}\s+
          line: MaxAuthTries {{ sshd_max_auth_tries_value }}
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_max_auth_tries

    - name: Set SSH authentication attempt limit - set file mode for /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_max_auth_tries
#### Rule Set SSH MaxSessions limit [ref]
The `MaxSessions` parameter specifies the maximum number of open sessions permitted from a given connection. To set MaxSessions edit `/etc/ssh/sshd_config` as follows:
    MaxSessions 10
Rationale: | To protect a system from denial of service due to a large number of concurrent sessions, use the rate limiting function of MaxSessions to protect availability of sshd logins and prevent overwhelming the daemon.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_set_max_sessions
References: |
cis | 4.2.18
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    var_sshd_max_sessions='10'

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    chmod 0600 /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

    LC_ALL=C sed -i "/^\s*MaxSessions\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*MaxSessions\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then

        LC_ALL=C sed -i "/^\s*MaxSessions\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    else
        touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

    cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "MaxSessions $var_sshd_max_sessions" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    cat "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_max_sessions
    - name: XCCDF Value var_sshd_max_sessions # promote to variable
      set_fact:
        var_sshd_max_sessions: !!str 10
      tags:
        - always

    - name: Set SSH MaxSessions limit - Check if the parameter MaxSessions is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "MaxSessions"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_max_sessions

    - name: Set SSH MaxSessions limit - Check if the parameter MaxSessions is configured
        correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "MaxSessions"| regex_escape }}\s+{{ var_sshd_max_sessions
          }}$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_max_sessions

    - name: Set SSH MaxSessions limit
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "MaxSessions"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter MaxSessions is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "MaxSessions"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "MaxSessions"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "MaxSessions"| regex_escape }}\s+
          line: MaxSessions {{ var_sshd_max_sessions }}
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_max_sessions

    - name: Set SSH MaxSessions limit - set file mode for /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_max_sessions
#### Rule Ensure SSH MaxStartups is configured [ref]
The MaxStartups parameter specifies the maximum number of concurrent unauthenticated connections to the SSH daemon. Additional connections will be dropped until authentication succeeds or the LoginGraceTime expires for a connection. To configure MaxStartups, you should add or edit the following line in the `/etc/ssh/sshd_config` file:
    MaxStartups 10:30:60
Rationale: | To protect a system from denial of service due to a large number of pending authentication connection attempts, use the rate limiting function of MaxStartups to protect availability of sshd logins and prevent overwhelming the daemon.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_sshd_set_maxstartups
References: |
cis | 4.2.17
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    var_sshd_set_maxstartups='10:30:60'

    mkdir -p /etc/ssh/sshd_config.d
    touch /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
    chmod 0600 /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf

    LC_ALL=C sed -i "/^\s*MaxStartups\s\+/Id" "/etc/ssh/sshd_config"
    LC_ALL=C sed -i "/^\s*MaxStartups\s\+/Id" "/etc/ssh/sshd_config.d"/*.conf
    if [ -e "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" ] ; then

        LC_ALL=C sed -i "/^\s*MaxStartups\s\+/Id" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    else
        touch "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    fi
    # make sure file has newline at the end
    sed -i -e '$a\' "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"

    cp "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf" "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"
    # Insert at the beginning of the file
    printf '%s\n' "MaxStartups $var_sshd_set_maxstartups" > "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    cat "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak" >> "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf"
    # Clean up after ourselves.
    rm "/etc/ssh/sshd_config.d/00-complianceascode-hardening.conf.bak"

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_maxstartups
    - name: XCCDF Value var_sshd_set_maxstartups # promote to variable
      set_fact:
        var_sshd_set_maxstartups: !!str 10:30:60
      tags:
        - always

    - name: Ensure SSH MaxStartups is configured - Check if the parameter MaxStartups
        is configured
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "MaxStartups"| regex_escape }}\s+
      register: _sshd_config_has_parameter
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_maxstartups

    - name: Ensure SSH MaxStartups is configured - Check if the parameter MaxStartups
        is configured correctly
      ansible.builtin.find:
        paths:
        - /etc/ssh/sshd_config
        - /etc/ssh/sshd_config.d
        contains: (?i)^\s*{{ "MaxStartups"| regex_escape }}\s+{{ var_sshd_set_maxstartups
          }}$
      register: _sshd_config_correctly
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_maxstartups

    - name: Ensure SSH MaxStartups is configured
      block:

      - name: Deduplicate values from /etc/ssh/sshd_config
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config
          create: false
          regexp: (?i)(?i)^\s*{{ "MaxStartups"| regex_escape }}\s+
          state: absent

      - name: Check if /etc/ssh/sshd_config.d exists
        ansible.builtin.stat:
          path: /etc/ssh/sshd_config.d
        register: _etc_ssh_sshd_config_d_exists

      - name: Check if the parameter MaxStartups is present in /etc/ssh/sshd_config.d
        ansible.builtin.find:
          paths: /etc/ssh/sshd_config.d
          recurse: 'yes'
          follow: 'no'
          contains: (?i)^\s*{{ "MaxStartups"| regex_escape }}\s+
        register: _etc_ssh_sshd_config_d_has_parameter
        when: _etc_ssh_sshd_config_d_exists.stat.isdir is defined and _etc_ssh_sshd_config_d_exists.stat.isdir

      - name: Remove parameter from files in /etc/ssh/sshd_config.d
        ansible.builtin.lineinfile:
          path: '{{ item.path }}'
          create: false
          regexp: (?i)(?i)^\s*{{ "MaxStartups"| regex_escape }}\s+
          state: absent
        with_items: '{{ _etc_ssh_sshd_config_d_has_parameter.files }}'
        when: _etc_ssh_sshd_config_d_has_parameter.matched > 0

      - name: Insert correct line to /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        ansible.builtin.lineinfile:
          path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
          create: true
          regexp: (?i)(?i)^\s*{{ "MaxStartups"| regex_escape }}\s+
          line: MaxStartups {{ var_sshd_set_maxstartups }}
          state: present
          insertbefore: BOF
          validate: /usr/sbin/sshd -t -f %s
      when:
      - '"kernel" in ansible_facts.packages'
      - _sshd_config_correctly.matched == 0 or _sshd_config_has_parameter.matched != 1
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_maxstartups

    - name: Ensure SSH MaxStartups is configured - set file mode for /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
      ansible.builtin.file:
        path: /etc/ssh/sshd_config.d/00-complianceascode-hardening.conf
        mode: '0600'
        state: touch
        modification_time: preserve
        access_time: preserve
      when: '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
      - sshd_set_maxstartups
#### Rule Verify Group Who Owns SSH Server config file [ref]
To properly set the group owner of `/etc/ssh/sshd_config`, run the command:
    $ sudo chgrp root /etc/ssh/sshd_config
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupowner_sshd_config
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | AC-17(a), CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 4.2.1
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/etc/ssh/sshd_config" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /etc/ssh/sshd_config
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_groupowner_sshd_config
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupowner_sshd_config_newgroup variable if represented by gid
      ansible.builtin.set_fact:
        file_groupowner_sshd_config_newgroup: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_groupowner_sshd_config
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/ssh/sshd_config
      ansible.builtin.stat:
        path: /etc/ssh/sshd_config
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_groupowner_sshd_config
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/ssh/sshd_config
      ansible.builtin.file:
        path: /etc/ssh/sshd_config
        follow: false
        group: '{{ file_groupowner_sshd_config_newgroup }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_groupowner_sshd_config
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Ownership on SSH Server Private *_key Key Files [ref]
SSH server private keys, files that match the `/etc/ssh/*_key` glob, must be group-owned by `ssh_keys` group. Warning: Remediation is not possible at bootable container build time because SSH host keys are generated post-deployment.
Rationale: | If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupownership_sshd_private_key
References: |
anssi | R50
cis | 4.2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newgroup=""
    if getent group "ssh_keys" >/dev/null 2>&1; then
      newgroup="ssh_keys"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "ssh_keys is not a defined group on the system"
    else
    find -P /etc/ssh/ -maxdepth 1 -type f  ! -group ssh_keys -regextype posix-extended -regex '^.*_key$' -exec chgrp --no-dereference "$newgroup" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - file_groupownership_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Check that the ssh_keys group is defined
      ansible.builtin.getent:
        database: group
        key: ssh_keys
      ignore_errors: true
      when:
      - '"kernel" in ansible_facts.packages'
      - file_groupownership_sshd_private_key_newgroup is undefined
      tags:
      - configure_strategy
      - file_groupownership_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupownership_sshd_private_key_newgroup variable if ssh_keys
        found
      ansible.builtin.set_fact:
        file_groupownership_sshd_private_key_newgroup: ssh_keys
      when:
      - '"kernel" in ansible_facts.packages'
      - ansible_facts.getent_group["ssh_keys"] is defined
      tags:
      - configure_strategy
      - file_groupownership_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/ssh/ file(s) matching ^.*_key$
      ansible.builtin.command: find -P /etc/ssh/ -maxdepth 1 -type f  ! -group ssh_keys
        -regextype posix-extended -regex "^.*_key$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/ssh/ file(s) matching ^.*_key$
      ansible.builtin.file:
        path: '{{ item }}'
        follow: false
        group: '{{ file_groupownership_sshd_private_key_newgroup }}'
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Group Ownership on SSH Server Public *.pub Key Files [ref]
SSH server public keys, files that match the `/etc/ssh/*.pub` glob, must be group-owned by `root` group. Warning: Remediation is not possible at bootable container build time because SSH host keys are generated post-deployment.
Rationale: | If a public host key file is modified by an unauthorized user, the SSH service may be compromised.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupownership_sshd_pub_key
References: |
anssi | R50
cis | 4.2.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    find -P /etc/ssh/ -maxdepth 1 -type f  ! -group 0 -regextype posix-extended -regex '^.*\.pub$' -exec chgrp --no-dereference "$newgroup" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - file_groupownership_sshd_pub_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupownership_sshd_pub_key_newgroup variable if represented
        by gid
      ansible.builtin.set_fact:
        file_groupownership_sshd_pub_key_newgroup: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_sshd_pub_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/ssh/ file(s) matching ^.*\.pub$
      ansible.builtin.command: find -P /etc/ssh/ -maxdepth 1 -type f  ! -group 0 -regextype
        posix-extended -regex "^.*\.pub$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_sshd_pub_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/ssh/ file(s) matching ^.*\.pub$
      ansible.builtin.file:
        path: '{{ item }}'
        follow: false
        group: '{{ file_groupownership_sshd_pub_key_newgroup }}'
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_sshd_pub_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Owner on SSH Server config file [ref]
To properly set the owner of `/etc/ssh/sshd_config`, run the command:
    $ sudo chown root /etc/ssh/sshd_config
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_owner_sshd_config
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | AC-17(a), CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 4.2.1
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/etc/ssh/sshd_config" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /etc/ssh/sshd_config
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_owner_sshd_config
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_owner_sshd_config_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_owner_sshd_config_newown: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_owner_sshd_config
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/ssh/sshd_config
      ansible.builtin.stat:
        path: /etc/ssh/sshd_config
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_owner_sshd_config
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/ssh/sshd_config
      ansible.builtin.file:
        path: /etc/ssh/sshd_config
        follow: false
        owner: '{{ file_owner_sshd_config_newown }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - configure_strategy
      - file_owner_sshd_config
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Ownership on SSH Server Private *_key Key Files [ref]
SSH server private keys, files that match the `/etc/ssh/*_key` glob, must be owned by `root` user. Warning: Remediation is not possible at bootable container build time because SSH host keys are generated post-deployment.
Rationale: | If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_ownership_sshd_private_key
References: |
anssi | R50
cis | 4.2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else

    find -P /etc/ssh/ -maxdepth 1 -type f  ! -user 0 -regextype posix-extended -regex '^.*_key$' -exec chown --no-dereference "$newown" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - file_ownership_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_ownership_sshd_private_key_newown variable if represented by
        uid
      ansible.builtin.set_fact:
        file_ownership_sshd_private_key_newown: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/ssh/ file(s) matching ^.*_key$
      ansible.builtin.command: find -P /etc/ssh/ -maxdepth 1 -type f  ! -user 0 -regextype
        posix-extended -regex "^.*_key$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/ssh/ file(s) matching ^.*_key$
      ansible.builtin.file:
        path: '{{ item }}'
        follow: false
        owner: '{{ file_ownership_sshd_private_key_newown }}'
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Ownership on SSH Server Public *.pub Key Files [ref]
SSH server public keys, files that match the `/etc/ssh/*.pub` glob, must be owned by `root` user. Warning: Remediation is not possible at bootable container build time because SSH host keys are generated post-deployment.
Rationale: | If a public host key file is modified by an unauthorized user, the SSH service may be compromised.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_ownership_sshd_pub_key
References: |
anssi | R50
cis | 4.2.3
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else

    find -P /etc/ssh/ -maxdepth 1 -type f  ! -user 0 -regextype posix-extended -regex '^.*\.pub$' -exec chown --no-dereference "$newown" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - file_ownership_sshd_pub_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_ownership_sshd_pub_key_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_ownership_sshd_pub_key_newown: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_sshd_pub_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/ssh/ file(s) matching ^.*\.pub$
      ansible.builtin.command: find -P /etc/ssh/ -maxdepth 1 -type f  ! -user 0 -regextype
        posix-extended -regex "^.*\.pub$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_sshd_pub_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/ssh/ file(s) matching ^.*\.pub$
      ansible.builtin.file:
        path: '{{ item }}'
        follow: false
        owner: '{{ file_ownership_sshd_pub_key_newown }}'
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_sshd_pub_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on SSH Server config file [ref]
To properly set the permissions of `/etc/ssh/sshd_config`, run the command:
    $ sudo chmod 0600 /etc/ssh/sshd_config
Rationale: | Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_sshd_config
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | AC-17(a), CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 4.2.1
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    chmod u-xs,g-xwrs,o-xwrt /etc/ssh/sshd_config

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_sshd_config
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /etc/ssh/sshd_config
      ansible.builtin.stat:
        path: /etc/ssh/sshd_config
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_sshd_config
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-xs,g-xwrs,o-xwrt on /etc/ssh/sshd_config
      ansible.builtin.file:
        path: /etc/ssh/sshd_config
        mode: u-xs,g-xwrs,o-xwrt
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_sshd_config
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify Permissions on SSH Server Private *_key Key Files [ref]
SSH server private keys - files that match the `/etc/ssh/*_key` glob, have to have restricted permissions. If those files are owned by the `root` user and the `root` group, they have to have the `0600` permission or stricter. If they are owned by the `root` user, but by a dedicated group `ssh_keys`, they can have the `0640` permission or stricter. Warning: Remediation is not possible at bootable container build time because SSH host keys are generated post-deployment.
Rationale: | If an unauthorized user obtains the private SSH host key file, the host could be impersonated.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_sshd_private_key
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
cui | 3.1.13, 3.13.10
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | AC-17(a), CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-2.2.4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 4.2.2
ism | 1449
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    for keyfile in /etc/ssh/*_key; do
        test -f "$keyfile" || continue
        if test root:root = "$(stat -c "%U:%G" "$keyfile")"; then

    	chmod u-xs,g-xwrs,o-xwrt "$keyfile"

        elif test root:ssh_keys = "$(stat -c "%U:%G" "$keyfile")"; then
    	chmod u-xs,g-xws,o-xwrt "$keyfile"
        else
            echo "Key-like file '$keyfile' is owned by an unexpected user:group combination"
        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.13
      - NIST-800-171-3.13.10
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find root:root-owned keys
      ansible.builtin.command: find -H /etc/ssh/ -maxdepth 1 -user root -regex ".*_key$"
        -type f -group root -perm /u+xs,g+xwrs,o+xwrt
      register: root_owned_keys
      changed_when: false
      failed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.13
      - NIST-800-171-3.13.10
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for root:root-owned keys
      ansible.builtin.file:
        path: '{{ item }}'
        mode: u-xs,g-xwrs,o-xwrt
        state: file
      with_items:
      - '{{ root_owned_keys.stdout_lines }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.13
      - NIST-800-171-3.13.10
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find root:ssh_keys-owned keys
      ansible.builtin.command: find -H /etc/ssh/ -maxdepth 1 -user root -regex ".*_key$"
        -type f -group ssh_keys -perm /u+xs,g+xws,o+xwrt
      register: dedicated_group_owned_keys
      changed_when: false
      failed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.13
      - NIST-800-171-3.13.10
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for root:ssh_keys-owned keys
      ansible.builtin.file:
        path: '{{ item }}'
        mode: u-xs,g-xws,o-xwrt
        state: file
      with_items:
      - '{{ dedicated_group_owned_keys.stdout_lines }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.13
      - NIST-800-171-3.13.10
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_sshd_private_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
Remediation Puppet snippet ⇲
    include ssh_private_key_perms

    class ssh_private_key_perms {
      exec { 'sshd_priv_key':
        command => "chmod 0640 /etc/ssh/*_key",
        path    => '/bin:/usr/bin'
      }
    }
#### Rule Verify Permissions on SSH Server Public *.pub Key Files [ref]
To properly set the permissions of `/etc/ssh/*.pub`, run the command:
    $ sudo chmod 0644 /etc/ssh/*.pub
Warning: Remediation is not possible at bootable container build time because SSH host keys are generated post-deployment.
Rationale: | If a public host key file is modified by an unauthorized user, the SSH service may be compromised.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_sshd_pub_key
References: |
cis-csc | 12, 13, 14, 15, 16, 18, 3, 5
cobit5 | APO01.06, DSS05.04, DSS05.07, DSS06.02
cui | 3.1.13, 3.13.10
isa-62443-2009 | 4.3.3.7.3
isa-62443-2013 | SR 2.1, SR 5.2
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | AC-17(a), CM-6(a), AC-6(1)
nist-csf | PR.AC-4, PR.DS-5
pcidss | Req-2.2.4
os-srg | SRG-OS-000480-GPOS-00227
anssi | R50
cis | 4.2.3
pcidss4 | 2.2.6, 2.2
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    find -P /etc/ssh/ -maxdepth 1 -perm /u+xs,g+xws,o+xwt  -type f -regextype posix-extended -regex '^.*\.pub$' -exec chmod u-xs,g-xws,o-xwt {} \;

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.13
      - NIST-800-171-3.13.10
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_sshd_pub_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/ssh/ file(s)
      ansible.builtin.command: find -P /etc/ssh/ -maxdepth 1 -perm /u+xs,g+xws,o+xwt  -type
        f -regextype posix-extended -regex "^.*\.pub$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.13
      - NIST-800-171-3.13.10
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_sshd_pub_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for /etc/ssh/ file(s)
      ansible.builtin.file:
        path: '{{ item }}'
        mode: u-xs,g-xws,o-xwt
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.13
      - NIST-800-171-3.13.10
      - NIST-800-53-AC-17(a)
      - NIST-800-53-AC-6(1)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-2.2.4
      - PCI-DSSv4-2.2
      - PCI-DSSv4-2.2.6
      - configure_strategy
      - file_permissions_sshd_pub_key
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
Remediation Puppet snippet ⇲
    include ssh_public_key_perms

    class ssh_public_key_perms {
      exec { 'sshd_pub_key':
        command => "chmod 0644 /etc/ssh/*.pub",
        path    => '/bin:/usr/bin'
      }
    }
Group X Window System Group contains 1 group and 1 rule
[ref] The X Window System implementation included with the system is called X.org.
Group Disable X Windows Group contains 1 rule
[ref] Unless there is a mission-critical reason for the system to run a graphical user interface, ensure X is not set to start automatically at boot and remove the X Windows software packages. There is usually no reason to run X Windows on a dedicated server system, as it increases the system's attack surface and consumes system resources. Administrators of server systems should instead login via SSH or on the text console.
#### Rule Remove the X Windows Package Group [ref]
By removing the xorg-x11-server-common package, the system no longer has X Windows installed. If X Windows is not installed then the system cannot boot into graphical user mode. This prevents the system from being accidentally or maliciously booted into a `graphical.target` mode. To do so, run the following command:
    $ sudo dnf groupremove "X Window System"
    $ sudo dnf remove xorg-x11-server-common
Warning: The installation and use of a Graphical User Interface (GUI) increases your attack vector and decreases your overall security posture. Removing the package xorg-x11-server-common package will remove the graphical target which might bring your system to an inconsistent state requiring additional configuration to access the system again. If a GUI is an operational requirement, a tailored profile that removes this rule should used before continuing installation.
Rationale: | Unnecessary service packages must not be installed to decrease the attack surface of the system. X windows has a long history of security vulnerabilities and should not be installed unless approved and documented.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_package_xorg-x11-server-common_removed
References: |
cis-csc | 12, 15, 8
cobit5 | APO13.01, DSS01.04, DSS05.02, DSS05.03
isa-62443-2009 | 4.3.3.6.6
isa-62443-2013 | SR 1.13, SR 2.6, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.13.1.1, A.13.2.1, A.14.1.3, A.6.2.1, A.6.2.2
nist | CM-7(a), CM-7(b), CM-6(a)
nist-csf | PR.AC-3, PR.PT-4
os-srg | SRG-OS-000480-GPOS-00227
cis | 2.2.1
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    # CAUTION: This remediation script will remove xorg-x11-server-common
    # from the system, and may remove any packages
    # that depend on xorg-x11-server-common. Execute this
    # remediation AFTER testing on a non-production
    # system!

    if rpm -q --quiet "xorg-x11-server-common" ; then
    dnf remove -y --noautoremove "xorg-x11-server-common"
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    package --remove=xorg-x11-server-common
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    - name: 'Remove the X Windows Package Group: Ensure xorg-x11-server-common is removed'
      ansible.builtin.package:
        name: xorg-x11-server-common
        state: absent
      tags:
      - NIST-800-53-CM-6(a)
      - NIST-800-53-CM-7(a)
      - NIST-800-53-CM-7(b)
      - disable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_xorg-x11-server-common_removed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | disable
    include remove_xorg-x11-server-common

    class remove_xorg-x11-server-common {
      package { 'xorg-x11-server-common':
        ensure => 'purged',
      }
    }
Group System Accounting with auditd Group contains 12 groups and 74 rules
[ref] The audit service provides substantial capabilities for recording system activities. By default, the service audits about SELinux AVC denials and certain types of security-relevant events such as system logins, account modifications, and authentication events performed by programs such as sudo. Under its default configuration, `auditd` has modest disk space requirements, and should not noticeably impact system performance. NOTE: The Linux Audit daemon `auditd` can be configured to use the `augenrules` program to read audit rules files (`*.rules`) located in `/etc/audit/rules.d` location and compile them to create the resulting form of the `/etc/audit/audit.rules` configuration file during the daemon startup (default configuration). Alternatively, the `auditd` daemon can use the `auditctl` utility to read audit rules from the `/etc/audit/audit.rules` configuration file during daemon startup, and load them into the kernel. The expected behavior is configured via the appropriate `ExecStartPost` directive setting in the `/usr/lib/systemd/system/auditd.service` configuration file. To instruct the `auditd` daemon to use the `augenrules` program to read audit rules (default configuration), use the following setting:
    ExecStartPost=-/sbin/augenrules --load
in the `/usr/lib/systemd/system/auditd.service` configuration file. In order to instruct the `auditd` daemon to use the `auditctl` utility to read audit rules, use the following setting:
    ExecStartPost=-/sbin/auditctl -R /etc/audit/audit.rules
in the `/usr/lib/systemd/system/auditd.service` configuration file. Refer to `[Service]` section of the `/usr/lib/systemd/system/auditd.service` configuration file for further details. Government networks often have substantial auditing requirements and `auditd` can be configured to meet these requirements. Examining some example audit records demonstrates how the Linux audit system satisfies common requirements. The following example from Red Hat Enterprise Linux 7 Documentation available at `https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html-single/selinux_users_and_administrators_guide/index#sect-Security-Enhanced_Linux-Fixing_Problems-Raw_Audit_Messages` shows the substantial amount of information captured in a two typical "raw" audit messages, followed by a breakdown of the most important fields. In this example the message is SELinux-related and reports an AVC denial (and the associated system call) that occurred when the Apache HTTP Server attempted to access the `/var/www/html/file1` file (labeled with the `samba_share_t` type):
    type=AVC msg=audit(1226874073.147:96): avc:  denied  { getattr } for pid=2465 comm="httpd"
    path="/var/www/html/file1" dev=dm-0 ino=284133 scontext=unconfined_u:system_r:httpd_t:s0
    tcontext=unconfined_u:object_r:samba_share_t:s0 tclass=file

    type=SYSCALL msg=audit(1226874073.147:96): arch=40000003 syscall=196 success=no exit=-13
    a0=b98df198 a1=bfec85dc a2=54dff4 a3=2008171 items=0 ppid=2463 pid=2465 auid=502 uid=48
    gid=48 euid=48 suid=48 fsuid=48 egid=48 sgid=48 fsgid=48 tty=(none) ses=6 comm="httpd"
    exe="/usr/sbin/httpd" subj=unconfined_u:system_r:httpd_t:s0 key=(null)
`msg=audit(1226874073.147:96)` The number in parentheses is the unformatted time stamp (Epoch time) for the event, which can be converted to standard time by using the `date` command. `{ getattr }` The item in braces indicates the permission that was denied. `getattr` indicates the source process was trying to read the target file's status information. This occurs before reading files. This action is denied due to the file being accessed having the wrong label. Commonly seen permissions include `getattr`, `read`, and `write`. `comm="httpd"` The executable that launched the process. The full path of the executable is found in the `exe=` section of the system call (`SYSCALL`) message, which in this case, is `exe="/usr/sbin/httpd"`. `path="/var/www/html/file1"` The path to the object (target) the process attempted to access. `scontext="unconfined_u:system_r:httpd_t:s0"` The SELinux context of the process that attempted the denied action. In this case, it is the SELinux context of the Apache HTTP Server, which is running in the `httpd_t` domain. `tcontext="unconfined_u:object_r:samba_share_t:s0"` The SELinux context of the object (target) the process attempted to access. In this case, it is the SELinux context of `file1`. Note: the `samba_share_t` type is not accessible to processes running in the `httpd_t` domain. From the system call (`SYSCALL`) message, two items are of interest: `success=no`: indicates whether the denial (AVC) was enforced or not. `success=no` indicates the system call was not successful (SELinux denied access). `success=yes` indicates the system call was successful - this can be seen for permissive domains or unconfined domains, such as `initrc_t` and `kernel_t`. `exe="/usr/sbin/httpd"`: the full path to the executable that launched the process, which in this case, is `exe="/usr/sbin/httpd"`.
Group Configure auditd Rules for Comprehensive Auditing Group contains 9 groups and 62 rules
[ref] The `auditd` program can perform comprehensive monitoring of system activity. This section describes recommended configuration settings for comprehensive auditing, but a full description of the auditing system's capabilities is beyond the scope of this guide. The mailing list linux-audit@redhat.com exists to facilitate community discussion of the auditing system. The audit subsystem supports extensive collection of events, including: Tracing of arbitrary system calls (identified by name or number) on entry or exit. Filtering by PID, UID, call success, system call argument (with some limitations), etc. Monitoring of specific files for modifications to the file's contents or metadata. Auditing rules at startup are controlled by the file `/etc/audit/audit.rules`. Add rules to it to meet the auditing requirements for your organization. Each line in `/etc/audit/audit.rules` represents a series of arguments that can be passed to `auditctl` and can be individually tested during runtime. See documentation in `/usr/share/doc/audit-VERSION` and in the related man pages for more details. If copying any example audit rulesets from `/usr/share/doc/audit-VERSION`, be sure to comment out the lines containing `arch=` which are not appropriate for your system's architecture. Then review and understand the following rules, ensuring rules are activated as needed for the appropriate architecture. After reviewing all the rules, reading the following sections, and editing as needed, the new rules can be activated as follows:
    $ sudo service auditd restart
Group Record Events that Modify the System's Discretionary Access Controls Group contains 13 rules
[ref] At a minimum, the audit system should collect file permission changes for all users and root. Note that the "-F arch=b32" lines should be present even on a 64 bit system. These commands identify system calls for auditing. Even if the system is 64 bit it can still execute 32 bit system calls. Additionally, these rules can be configured in a number of ways while still achieving the desired effect. An example of this is that the "-S" calls could be split up and placed on separate lines, however, this is less efficient. Add the following to `/etc/audit/audit.rules`:
    -a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod

        -a always,exit -F arch=b32 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
        -a always,exit -F arch=b32 -S setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If your system is 64 bit then these lines should be duplicated and the arch=b32 replaced with arch=b64 as follows:
    -a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod

        -a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
        -a always,exit -F arch=b64 -S setxattr,lsetxattr,fsetxattr,removexattr,lremovexattr,fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
#### Rule Record Events that Modify the System's Discretionary Access Controls - chmod [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S chmod -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_chmod
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
anssi | R73
cis | 5.2.3.9
ism | 0582
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel && { ( ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ) ); }; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="chmod"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="chmod fchmod fchmodat"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_chmod
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit chmod tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_chmod
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for chmod for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - chmod
          syscall_grouping:
          - chmod
          - fchmod
          - fchmodat

      - name: Check existence of chmod in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - chmod
          syscall_grouping:
          - chmod
          - fchmod
          - fchmodat

      - name: Check existence of chmod in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_chmod
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for chmod for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - chmod
          syscall_grouping:
          - chmod
          - fchmod
          - fchmodat

      - name: Check existence of chmod in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - chmod
          syscall_grouping:
          - chmod
          - fchmod
          - fchmodat

      - name: Check existence of chmod in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_chmod
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Discretionary Access Controls - chown [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S chown -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_chown
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
anssi | R73
cis | 5.2.3.9
ism | 0582
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel && { ( ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ) ); }; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="chown"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="chown fchown fchownat lchown"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_chown
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit chown tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_chown
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for chown for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - chown
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of chown in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - chown
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of chown in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_chown
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for chown for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - chown
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of chown in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - chown
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of chown in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_chown
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Discretionary Access Controls - fchmod [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchmod -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fchmod
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
anssi | R73
cis | 5.2.3.9
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="fchmod"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="chmod fchmod fchmodat"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchmod
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit fchmod tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchmod
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for fchmod for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchmod
          syscall_grouping:
          - chmod
          - fchmod
          - fchmodat

      - name: Check existence of fchmod in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchmod
          syscall_grouping:
          - chmod
          - fchmod
          - fchmodat

      - name: Check existence of fchmod in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchmod
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for fchmod for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchmod
          syscall_grouping:
          - chmod
          - fchmod
          - fchmodat

      - name: Check existence of fchmod in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchmod
          syscall_grouping:
          - chmod
          - fchmod
          - fchmodat

      - name: Check existence of fchmod in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchmod
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Discretionary Access Controls - fchmodat [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchmodat -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fchmodat
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
anssi | R73
cis | 5.2.3.9
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="fchmodat"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="chmod fchmod fchmodat"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchmodat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit fchmodat tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchmodat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for fchmodat for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchmodat
          syscall_grouping:
          - chmod
          - fchmod
          - fchmodat

      - name: Check existence of fchmodat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchmodat
          syscall_grouping:
          - chmod
          - fchmod
          - fchmodat

      - name: Check existence of fchmodat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchmodat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for fchmodat for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchmodat
          syscall_grouping:
          - chmod
          - fchmod
          - fchmodat

      - name: Check existence of fchmodat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchmodat
          syscall_grouping:
          - chmod
          - fchmod
          - fchmodat

      - name: Check existence of fchmodat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchmodat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Discretionary Access Controls - fchown [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchown -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fchown
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
anssi | R73
cis | 5.2.3.9
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="fchown"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="chown fchown fchownat lchown"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchown
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit fchown tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchown
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for fchown for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchown
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of fchown in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchown
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of fchown in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchown
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for fchown for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchown
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of fchown in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchown
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of fchown in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchown
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Discretionary Access Controls - fchownat [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fchownat -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fchownat
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
anssi | R73
cis | 5.2.3.9
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="fchownat"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="chown fchown fchownat lchown"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchownat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit fchownat tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchownat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for fchownat for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchownat
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of fchownat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchownat
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of fchownat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchownat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for fchownat for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchownat
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of fchownat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fchownat
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of fchownat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fchownat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Discretionary Access Controls - fremovexattr [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fremovexattr
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212, SRG-OS-000064-GPOS-00033
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000499-CTR-001255
anssi | R73
cis | 5.2.3.9
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="fremovexattr"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fremovexattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit fremovexattr tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fremovexattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for fremovexattr for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fremovexattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of fremovexattr in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fremovexattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of fremovexattr in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fremovexattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for fremovexattr for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fremovexattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of fremovexattr in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fremovexattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of fremovexattr in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fremovexattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Discretionary Access Controls - fsetxattr [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S fsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_fsetxattr
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000064-GPOS-00033
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270
anssi | R73
cis | 5.2.3.9
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="fsetxattr"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fsetxattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit fsetxattr tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fsetxattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for fsetxattr for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fsetxattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of fsetxattr in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fsetxattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of fsetxattr in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fsetxattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for fsetxattr for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fsetxattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of fsetxattr in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - fsetxattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of fsetxattr in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_fsetxattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Discretionary Access Controls - lchown [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S lchown -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_lchown
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203, SRG-OS-000474-GPOS-00219
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
anssi | R73
cis | 5.2.3.9
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel && { ( ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ) ); }; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="lchown"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="chown fchown fchownat lchown"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_lchown
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit lchown tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_lchown
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for lchown for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - lchown
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of lchown in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - lchown
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of lchown in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_lchown
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for lchown for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - lchown
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of lchown in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - lchown
          syscall_grouping:
          - chown
          - fchown
          - fchownat
          - lchown

      - name: Check existence of lchown in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_lchown
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Discretionary Access Controls - lremovexattr [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S lremovexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_lremovexattr
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000466-GPOS-00210, SRG-OS-000064-GPOS-00033
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000499-CTR-001255, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270
anssi | R73
cis | 5.2.3.9
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="lremovexattr"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_lremovexattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit lremovexattr tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_lremovexattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for lremovexattr for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - lremovexattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of lremovexattr in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - lremovexattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of lremovexattr in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_lremovexattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for lremovexattr for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - lremovexattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of lremovexattr in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - lremovexattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of lremovexattr in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_lremovexattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Discretionary Access Controls - lsetxattr [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S lsetxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_lsetxattr
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000466-GPOS-00210, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000064-GPOS-00033
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270
anssi | R73
cis | 5.2.3.9
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="lsetxattr"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_lsetxattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit lsetxattr tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_lsetxattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for lsetxattr for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - lsetxattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of lsetxattr in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - lsetxattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of lsetxattr in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_lsetxattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for lsetxattr for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - lsetxattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of lsetxattr in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - lsetxattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of lsetxattr in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_lsetxattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Discretionary Access Controls - removexattr [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S removexattr -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_removexattr
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000462-GPOS-00206, SRG-OS-000463-GPOS-00207, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000474-GPOS-00219, SRG-OS-000466-GPOS-00210, SRG-OS-000064-GPOS-00033
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000499-CTR-001255, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270
anssi | R73
cis | 5.2.3.9
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="removexattr"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_removexattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit removexattr tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_removexattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for removexattr for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - removexattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of removexattr in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - removexattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of removexattr in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_removexattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for removexattr for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - removexattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of removexattr in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - removexattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of removexattr in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_removexattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Discretionary Access Controls - setxattr [ref]
At a minimum, the audit system should collect file permission changes for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S setxattr -F auid>=1000 -F auid!=unset -F key=perm_mod
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_dac_modification_setxattr
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203
app-srg-ctr | SRG-APP-000091-CTR-000160, SRG-APP-000492-CTR-001220, SRG-APP-000493-CTR-001225, SRG-APP-000494-CTR-001230, SRG-APP-000500-CTR-001260, SRG-APP-000507-CTR-001295, SRG-APP-000495-CTR-001235
anssi | R73
cis | 5.2.3.9
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="setxattr"
    	KEY="perm_mod"
    	SYSCALL_GROUPING="fremovexattr lremovexattr removexattr fsetxattr lsetxattr setxattr"

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_setxattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit setxattr tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_setxattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for setxattr for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - setxattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of setxattr in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - setxattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of setxattr in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_setxattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for setxattr for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - setxattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of setxattr in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/perm_mod.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/perm_mod.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - setxattr
          syscall_grouping:
          - fremovexattr
          - lremovexattr
          - removexattr
          - fsetxattr
          - lsetxattr
          - setxattr

      - name: Check existence of setxattr in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=perm_mod
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_dac_modification_setxattr
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
Group Record Execution Attempts to Run ACL Privileged Commands Group contains 2 rules
[ref] At a minimum, the audit system should collect the execution of ACL privileged commands for all users and root.
#### Rule Record Any Attempts to Run chacl [ref]
At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/chacl -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/chacl -F auid>=1000 -F auid!=unset -F key=privileged
Rationale: | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_execution_chacl
References: |
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
cis | 5.2.3.17
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Retrieve hardware architecture of the underlying system
    OTHER_FILTERS="-F path=/usr/bin/chacl"
    AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    SYSCALL=""
    KEY="privileged"
    SYSCALL_GROUPING=""

    ACTION_ARCH_FILTERS="-a always,exit"
    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - audit_rules_execution_chacl
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Any Attempts to Run chacl - Perform remediation of Audit rules for
        /usr/bin/chacl
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls: []
          syscall_grouping: []

      - name: Check existence of  in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
            path=/usr/bin/chacl -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/chacl -F auid>=1000
            -F auid!=unset (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chacl -F auid>=1000
            -F auid!=unset -F key=privileged
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls: []
          syscall_grouping: []

      - name: Check existence of  in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
            path=/usr/bin/chacl -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
            -S |,)\w+)+)( -F path=/usr/bin/chacl -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chacl -F auid>=1000
            -F auid!=unset -F key=privileged
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - audit_rules_execution_chacl
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Any Attempts to Run setfacl [ref]
At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/setfacl -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/setfacl -F auid>=1000 -F auid!=unset -F key=privileged
Rationale: | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_execution_setfacl
References: |
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
app-srg-ctr | SRG-APP-000495-CTR-001235
cis | 5.2.3.16
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Retrieve hardware architecture of the underlying system
    OTHER_FILTERS="-F path=/usr/bin/setfacl"
    AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    SYSCALL=""
    KEY="privileged"
    SYSCALL_GROUPING=""

    ACTION_ARCH_FILTERS="-a always,exit"
    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - audit_rules_execution_setfacl
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Any Attempts to Run setfacl - Perform remediation of Audit rules for
        /usr/bin/setfacl
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls: []
          syscall_grouping: []

      - name: Check existence of  in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
            path=/usr/bin/setfacl -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/setfacl -F auid>=1000
            -F auid!=unset (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/setfacl -F auid>=1000
            -F auid!=unset -F key=privileged
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls: []
          syscall_grouping: []

      - name: Check existence of  in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
            path=/usr/bin/setfacl -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
            -S |,)\w+)+)( -F path=/usr/bin/setfacl -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/setfacl -F auid>=1000
            -F auid!=unset -F key=privileged
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - audit_rules_execution_setfacl
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
Group Record Execution Attempts to Run SELinux Privileged Commands Group contains 1 rule
[ref] At a minimum, the audit system should collect the execution of SELinux privileged commands for all users and root.
#### Rule Record Any Attempts to Run chcon [ref]
At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/chcon -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/chcon -F auid>=1000 -F auid!=unset -F key=privileged
Rationale: | Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_execution_chcon
References: |
cis-csc | 1, 12, 13, 14, 15, 16, 2, 3, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, BAI03.05, DSS01.03, DSS03.05, DSS05.02, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 6.2
iso27001-2013 | A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.14.2.7, A.15.2.1, A.15.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.PT-1
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00215, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270
cis | 5.2.3.15
ism | 0582
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Retrieve hardware architecture of the underlying system
    OTHER_FILTERS="-F path=/usr/bin/chcon"
    AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    SYSCALL=""
    KEY="privileged"
    SYSCALL_GROUPING=""

    ACTION_ARCH_FILTERS="-a always,exit"
    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - audit_rules_execution_chcon
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Any Attempts to Run chcon - Perform remediation of Audit rules for
        /usr/bin/chcon
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls: []
          syscall_grouping: []

      - name: Check existence of  in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
            path=/usr/bin/chcon -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/chcon -F auid>=1000
            -F auid!=unset (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chcon -F auid>=1000
            -F auid!=unset -F key=privileged
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls: []
          syscall_grouping: []

      - name: Check existence of  in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
            path=/usr/bin/chcon -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
            -S |,)\w+)+)( -F path=/usr/bin/chcon -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/chcon -F auid>=1000
            -F auid!=unset -F key=privileged
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - audit_rules_execution_chcon
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
Group Record File Deletion Events by User Group contains 4 rules
[ref] At a minimum, the audit system should collect file deletion events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S rmdir,unlink,unlinkat,rename,renameat,renameat2 -F auid>=1000 -F auid!=unset -F key=delete
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S rmdir,unlink,unlinkat,rename,renameat,renameat2 -F auid>=1000 -F auid!=unset -F key=delete
#### Rule Ensure auditd Collects File Deletion Events by User - rename [ref]
At a minimum, the audit system should collect file deletion events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S rename -F auid>=1000 -F auid!=unset -F key=delete
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S rename -F auid>=1000 -F auid!=unset -F key=delete
Rationale: | Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_file_deletion_events_rename
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.4, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.1.1, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.MA-2, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.7
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270
anssi | R73
cis | 5.2.3.13
pcidss4 | 10.2.1.7, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel && { ( ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ) ); }; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="rename"
    	KEY="delete"
    	SYSCALL_GROUPING="unlink unlinkat rename renameat renameat2 rmdir"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_rename
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit rename tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_rename
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for rename for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - rename
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of rename in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - rename
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of rename in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_rename
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for rename for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - rename
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of rename in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - rename
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of rename in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_rename
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Ensure auditd Collects File Deletion Events by User - renameat [ref]
At a minimum, the audit system should collect file deletion events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S renameat -F auid>=1000 -F auid!=unset -F key=delete
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S renameat -F auid>=1000 -F auid!=unset -F key=delete
Rationale: | Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_file_deletion_events_renameat
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.4, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.1.1, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.MA-2, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.7
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270
anssi | R73
cis | 5.2.3.13
pcidss4 | 10.2.1.7, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="renameat"
    	KEY="delete"
    	SYSCALL_GROUPING="unlink unlinkat rename renameat renameat2 rmdir"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_renameat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit renameat tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_renameat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for renameat for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - renameat
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of renameat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - renameat
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of renameat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_renameat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for renameat for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - renameat
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of renameat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - renameat
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of renameat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_renameat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Ensure auditd Collects File Deletion Events by User - unlink [ref]
At a minimum, the audit system should collect file deletion events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S unlink -F auid>=1000 -F auid!=unset -F key=delete
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S unlink -F auid>=1000 -F auid!=unset -F key=delete
Rationale: | Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_file_deletion_events_unlink
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.4, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.1.1, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.MA-2, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.7
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270
anssi | R73
cis | 5.2.3.13
pcidss4 | 10.2.1.7, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel && { ( ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ) ); }; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="unlink"
    	KEY="delete"
    	SYSCALL_GROUPING="unlink unlinkat rename renameat renameat2 rmdir"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_unlink
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit unlink tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_unlink
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for unlink for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - unlink
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of unlink in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - unlink
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of unlink in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_unlink
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for unlink for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - unlink
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of unlink in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - unlink
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of unlink in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_unlink
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Ensure auditd Collects File Deletion Events by User - unlinkat [ref]
At a minimum, the audit system should collect file deletion events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S unlinkat -F auid>=1000 -F auid!=unset -F key=delete
Rationale: | Auditing file deletions will create an audit trail for files that are removed from the system. The audit trail could aid in system troubleshooting, as well as, detecting malicious processes that attempt to delete log files to conceal their presence.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_file_deletion_events_unlinkat
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.5, 4.3.3.6.6, 4.3.3.6.7, 4.3.3.6.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.4, A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.1.1, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.MA-2, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.7
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000501-CTR-001265, SRG-APP-000502-CTR-001270
anssi | R73
cis | 5.2.3.13
pcidss4 | 10.2.1.7, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="unlinkat"
    	KEY="delete"
    	SYSCALL_GROUPING="unlink unlinkat rename renameat renameat2 rmdir"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_unlinkat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit unlinkat tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_unlinkat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for unlinkat for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - unlinkat
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of unlinkat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - unlinkat
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of unlinkat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_unlinkat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for unlinkat for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - unlinkat
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of unlinkat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/delete.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/delete.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - unlinkat
          syscall_grouping:
          - unlink
          - unlinkat
          - rename
          - renameat
          - renameat2
          - rmdir

      - name: Check existence of unlinkat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=delete
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_file_deletion_events_unlinkat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
Group Record Unauthorized Access Attempts Events to Files (unsuccessful) Group contains 5 rules
[ref] At a minimum, the audit system should collect unauthorized file accesses for all users and root. Note that the "-F arch=b32" lines should be present even on a 64 bit system. These commands identify system calls for auditing. Even if the system is 64 bit it can still execute 32 bit system calls. Additionally, these rules can be configured in a number of ways while still achieving the desired effect. An example of this is that the "-S" calls could be split up and placed on separate lines, however, this is less efficient. Add the following to `/etc/audit/audit.rules`:
    -a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
        -a always,exit -F arch=b32 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If your system is 64 bit then these lines should be duplicated and the arch=b32 replaced with arch=b64 as follows:
    -a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
        -a always,exit -F arch=b64 -S creat,open,openat,open_by_handle_at,truncate,ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
#### Rule Record Unsuccessful Access Attempts to Files - creat [ref]
At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S creat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S creat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_unsuccessful_file_modification_creat
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.4, Req-10.2.1
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205
app-srg-ctr | SRG-APP-000495-CTR-001235
anssi | R73
cis | 5.2.3.7
ism | 0582, 0846
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel && { ( ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ) ); }; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    SYSCALL="creat"
    KEY="access"
    SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS="-F exit=-EACCES"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS="-F exit=-EPERM"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_creat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit creat tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_creat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for creat EACCES for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - creat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of creat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - creat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of creat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_creat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for creat EACCES for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - creat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of creat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - creat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of creat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_creat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for creat EPERM for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - creat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of creat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - creat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of creat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_creat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for creat EPERM for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - creat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of creat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - creat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of creat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_creat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Unsuccessful Access Attempts to Files - ftruncate [ref]
At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S ftruncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S ftruncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_unsuccessful_file_modification_ftruncate
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.4, Req-10.2.1
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205
app-srg-ctr | SRG-APP-000495-CTR-001235
anssi | R73
cis | 5.2.3.7
ism | 0582, 0846
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    SYSCALL="ftruncate"
    KEY="access"
    SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS="-F exit=-EACCES"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS="-F exit=-EPERM"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_ftruncate
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit ftruncate tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_ftruncate
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for ftruncate EACCES for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - ftruncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of ftruncate in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - ftruncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of ftruncate in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_ftruncate
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for ftruncate EACCES for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - ftruncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of ftruncate in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - ftruncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of ftruncate in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_ftruncate
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for ftruncate EPERM for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - ftruncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of ftruncate in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - ftruncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of ftruncate in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_ftruncate
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for ftruncate EPERM for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - ftruncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of ftruncate in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - ftruncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of ftruncate in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_ftruncate
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Unsuccessful Access Attempts to Files - open [ref]
At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S open -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S open -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_unsuccessful_file_modification_open
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.4, Req-10.2.1
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205
app-srg-ctr | SRG-APP-000495-CTR-001235
anssi | R73
cis | 5.2.3.7
ism | 0582, 0846
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel && { ( ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ) ); }; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    SYSCALL="open"
    KEY="access"
    SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS="-F exit=-EACCES"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS="-F exit=-EPERM"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_open
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit open tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_open
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for open EACCES for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - open
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of open in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - open
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of open in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_open
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for open EACCES for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - open
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of open in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - open
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of open in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_open
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for open EPERM for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - open
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of open in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - open
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of open in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_open
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for open EPERM for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - open
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of open in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - open
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of open in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_open
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Unsuccessful Access Attempts to Files - openat [ref]
At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S openat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S openat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_unsuccessful_file_modification_openat
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.4, Req-10.2.1
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205
app-srg-ctr | SRG-APP-000495-CTR-001235
anssi | R73
cis | 5.2.3.7
ism | 0582, 0846
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    SYSCALL="openat"
    KEY="access"
    SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS="-F exit=-EACCES"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS="-F exit=-EPERM"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_openat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit openat tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_openat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for openat EACCES for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - openat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of openat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - openat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of openat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_openat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for openat EACCES for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - openat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of openat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - openat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of openat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_openat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for openat EPERM for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - openat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of openat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - openat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of openat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_openat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for openat EPERM for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - openat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of openat in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - openat
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of openat in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_openat
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Unsuccessful Access Attempts to Files - truncate [ref]
At a minimum, the audit system should collect unauthorized file accesses for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b32 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
If the system is 64 bit then also add the following lines:
    -a always,exit -F arch=b64 -S truncate -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=access
    -a always,exit -F arch=b64 -S truncate -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=access
Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect. Here the system calls have been placed independent of other system calls. Grouping these system calls with others as identifying earlier in this guide is more efficient.
Rationale: | Unsuccessful attempts to access files could be an indicator of malicious activity on a system. Auditing these events could serve as evidence of potential system compromise.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_unsuccessful_file_modification_truncate
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.4, Req-10.2.1
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205
app-srg-ctr | SRG-APP-000495-CTR-001235
anssi | R73
cis | 5.2.3.7
ism | 0582, 0846
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    SYSCALL="truncate"
    KEY="access"
    SYSCALL_GROUPING="creat ftruncate truncate open openat open_by_handle_at"

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS="-F exit=-EACCES"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS="-F exit=-EPERM"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_truncate
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit truncate tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_truncate
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for truncate EACCES for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - truncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of truncate in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - truncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of truncate in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_truncate
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for truncate EACCES for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - truncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of truncate in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - truncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of truncate in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EACCES -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EACCES -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EACCES
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_truncate
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for truncate EPERM for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - truncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of truncate in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - truncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of truncate in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_truncate
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for truncate EPERM for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - truncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of truncate in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/access.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/access.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - truncate
          syscall_grouping:
          - creat
          - ftruncate
          - truncate
          - open
          - openat
          - open_by_handle_at

      - name: Check existence of truncate in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F exit=-EPERM -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F exit=-EPERM -F auid>=1000 -F auid!=unset
            (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F exit=-EPERM
            -F auid>=1000 -F auid!=unset -F key=access
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.1
      - PCI-DSS-Req-10.2.4
      - audit_rules_unsuccessful_file_modification_truncate
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
Group Record Information on Kernel Modules Loading and Unloading Group contains 5 rules
[ref] To capture kernel module loading and unloading events, use following lines, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S init_module,delete_module -F key=modules
Place to add the lines depends on a way `auditd` daemon is configured. If it is configured to use the `augenrules` program (the default), add the lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility, add the lines to file `/etc/audit/audit.rules`.
#### Rule Ensure auditd Collects Information on Kernel Module Unloading - create_module [ref]
To capture kernel module loading and unloading events, use the following line, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S create_module -F key=modules
Place to add the line depends on a way `auditd` daemon is configured. If it is configured to use the `augenrules` program (the default), add the line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility, add the line to file `/etc/audit/audit.rules`.
Rationale: | The removal of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_kernel_module_loading_create
References: |
os-srg | SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
cis | 5.2.3.19
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel && { ( ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ) ); }; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    # Note: 32-bit and 64-bit kernel syscall numbers not always line up =>
    #       it's required on a 64-bit system to check also for the presence
    #       of 32-bit's equivalent of the corresponding rule.
    #       (See `man 7 audit.rules` for details )
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""

    	AUID_FILTERS=""

    	SYSCALL="create_module"
    	KEY="modules"
    	SYSCALL_GROUPING="create_module delete_module finit_module init_module query_module"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - audit_rules_kernel_module_loading_create
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Unloading - create_module
        - Set architecture for audit ['create_module'] tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - audit_rules_kernel_module_loading_create
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Unloading - create_module
        - Perform remediation of Audit rules for ['create_module'] for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - create_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of create_module in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - create_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of create_module in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      tags:
      - audit_rules_kernel_module_loading_create
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Unloading - create_module
        - Perform remediation of Audit rules for ['create_module'] for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - create_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of create_module in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - create_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of create_module in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - audit_arch == "b64"
      tags:
      - audit_rules_kernel_module_loading_create
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Ensure auditd Collects Information on Kernel Module Unloading - delete_module [ref]
To capture kernel module loading and unloading events, use the following line, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S delete_module -F key=modules
Place to add the line depends on a way `auditd` daemon is configured. If it is configured to use the `augenrules` program (the default), add the line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility, add the line to file `/etc/audit/audit.rules`.
Rationale: | The removal of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_kernel_module_loading_delete
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.7
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000504-CTR-001280
anssi | R73
cis | 5.2.3.19
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    # Note: 32-bit and 64-bit kernel syscall numbers not always line up =>
    #       it's required on a 64-bit system to check also for the presence
    #       of 32-bit's equivalent of the corresponding rule.
    #       (See `man 7 audit.rules` for details )
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""

    	AUID_FILTERS=""

    	SYSCALL="delete_module"
    	KEY="modules"
    	SYSCALL_GROUPING="create_module delete_module finit_module init_module query_module"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - audit_rules_kernel_module_loading_delete
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Unloading - delete_module
        - Set architecture for audit ['delete_module'] tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - audit_rules_kernel_module_loading_delete
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Unloading - delete_module
        - Perform remediation of Audit rules for ['delete_module'] for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - delete_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of delete_module in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - delete_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of delete_module in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - audit_rules_kernel_module_loading_delete
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Unloading - delete_module
        - Perform remediation of Audit rules for ['delete_module'] for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - delete_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of delete_module in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - delete_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of delete_module in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - audit_rules_kernel_module_loading_delete
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Ensure auditd Collects Information on Kernel Module Loading and Unloading - finit_module [ref]
To capture kernel module loading and unloading events, use the following line, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S finit_module -F key=modules
Place to add the line depends on a way `auditd` daemon is configured. If it is configured to use the `augenrules` program (the default), add the line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility, add the line to file `/etc/audit/audit.rules`.
Rationale: | The addition/removal of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_kernel_module_loading_finit
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.7
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000504-CTR-001280
anssi | R73
cis | 5.2.3.19
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    # Note: 32-bit and 64-bit kernel syscall numbers not always line up =>
    #       it's required on a 64-bit system to check also for the presence
    #       of 32-bit's equivalent of the corresponding rule.
    #       (See `man 7 audit.rules` for details )
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""

    	AUID_FILTERS=""

    	SYSCALL="finit_module"
    	KEY="modules"
    	SYSCALL_GROUPING="create_module delete_module finit_module init_module query_module"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - audit_rules_kernel_module_loading_finit
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Loading and Unloading
        - finit_module - Set architecture for audit ['finit_module'] tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - audit_rules_kernel_module_loading_finit
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Loading and Unloading
        - finit_module - Perform remediation of Audit rules for ['finit_module'] for 32bit
        platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - finit_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of finit_module in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - finit_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of finit_module in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - audit_rules_kernel_module_loading_finit
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Loading and Unloading
        - finit_module - Perform remediation of Audit rules for ['finit_module'] for 64bit
        platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - finit_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of finit_module in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - finit_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of finit_module in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - audit_rules_kernel_module_loading_finit
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Ensure auditd Collects Information on Kernel Module Loading - init_module [ref]
To capture kernel module loading and unloading events, use the following line, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S init_module -F key=modules
Place to add the line depends on a way `auditd` daemon is configured. If it is configured to use the `augenrules` program (the default), add the line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility, add the line to file `/etc/audit/audit.rules`.
Rationale: | The addition of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_kernel_module_loading_init
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.7
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000504-CTR-001280
anssi | R73
cis | 5.2.3.19
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    # Note: 32-bit and 64-bit kernel syscall numbers not always line up =>
    #       it's required on a 64-bit system to check also for the presence
    #       of 32-bit's equivalent of the corresponding rule.
    #       (See `man 7 audit.rules` for details )
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""

    	AUID_FILTERS=""

    	SYSCALL="init_module"
    	KEY="modules"
    	SYSCALL_GROUPING="create_module delete_module finit_module init_module query_module"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - audit_rules_kernel_module_loading_init
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Loading - init_module
        - Set architecture for audit ['init_module'] tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - audit_rules_kernel_module_loading_init
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Loading - init_module
        - Perform remediation of Audit rules for ['init_module'] for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - init_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of init_module in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - init_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of init_module in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - audit_rules_kernel_module_loading_init
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Loading - init_module
        - Perform remediation of Audit rules for ['init_module'] for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - init_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of init_module in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - init_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of init_module in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - audit_rules_kernel_module_loading_init
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Ensure auditd Collects Information on Kernel Module Loading and Unloading - query_module [ref]
To capture kernel module loading and unloading events, use the following line, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S query_module -F key=modules
Place to add the line depends on a way `auditd` daemon is configured. If it is configured to use the `augenrules` program (the default), add the line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`. If the `auditd` daemon is configured to use the `auditctl` utility, add the line to file `/etc/audit/audit.rules`.
Rationale: | The addition/removal of kernel modules can be used to alter the behavior of the kernel and potentially introduce malicious code into kernel space. It is important to have an audit trail of modules that have been introduced into the kernel.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_kernel_module_loading_query
References: |
cis | 5.2.3.19
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel && { ( ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ) ); }; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    # Note: 32-bit and 64-bit kernel syscall numbers not always line up =>
    #       it's required on a 64-bit system to check also for the presence
    #       of 32-bit's equivalent of the corresponding rule.
    #       (See `man 7 audit.rules` for details )
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""

    	AUID_FILTERS=""

    	SYSCALL="query_module"
    	KEY="modules"
    	SYSCALL_GROUPING="create_module delete_module finit_module init_module query_module"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - audit_rules_kernel_module_loading_query
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Loading and Unloading
        - query_module - Set architecture for audit ['query_module'] tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - audit_rules_kernel_module_loading_query
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Loading and Unloading
        - query_module - Perform remediation of Audit rules for ['query_module'] for 32bit
        platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - query_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of query_module in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - query_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of query_module in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      tags:
      - audit_rules_kernel_module_loading_query
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on Kernel Module Loading and Unloading
        - query_module - Perform remediation of Audit rules for ['query_module'] for 64bit
        platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - query_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of query_module in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/modules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/modules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - query_module
          syscall_grouping:
          - create_module
          - delete_module
          - finit_module
          - init_module
          - query_module

      - name: Check existence of query_module in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=modules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not ( ansible_architecture == "aarch64" )
      - audit_arch == "b64"
      tags:
      - audit_rules_kernel_module_loading_query
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
Group Record Attempts to Alter Logon and Logout Events Group contains 2 rules
[ref] The audit system already collects login information for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d` in order to watch for attempted manual edits of files involved in storing logon events:
    -w /var/log/tallylog -p wa -k logins
    -w /var/run/faillock -p wa -k logins
    -w /var/log/lastlog -p wa -k logins
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file in order to watch for unattempted manual edits of files involved in storing logon events:
    -w /var/log/tallylog -p wa -k logins
    -w /var/run/faillock -p wa -k logins
    -w /var/log/lastlog -p wa -k logins
#### Rule Record Attempts to Alter Logon and Logout Events - faillock [ref]
The audit system already collects login information for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /var/run/faillock -p wa -k logins
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /var/run/faillock -p wa -k logins
Rationale: | Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_login_events_faillock
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.3
os-srg | SRG-OS-000392-GPOS-00172, SRG-OS-000470-GPOS-00214, SRG-OS-000473-GPOS-00218
app-srg-ctr | SRG-APP-000503-CTR-001275, SRG-APP-000506-CTR-001290
anssi | R73
cis | 5.2.3.12
ism | 0582
pcidss4 | 10.2.1.3, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

    var_accounts_passwords_pam_faillock_dir='/var/run/faillock'

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+${var_accounts_passwords_pam_faillock_dir}" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+${var_accounts_passwords_pam_faillock_dir} $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+${var_accounts_passwords_pam_faillock_dir}$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w ${var_accounts_passwords_pam_faillock_dir} -p wa -k logins" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/logins.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+${var_accounts_passwords_pam_faillock_dir}" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/logins.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/logins.rules"
        # If the logins.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+${var_accounts_passwords_pam_faillock_dir}" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+${var_accounts_passwords_pam_faillock_dir} $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+${var_accounts_passwords_pam_faillock_dir}$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w ${var_accounts_passwords_pam_faillock_dir} -p wa -k logins" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_faillock
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_accounts_passwords_pam_faillock_dir # promote to variable
      set_fact:
        var_accounts_passwords_pam_faillock_dir: !!str /var/run/faillock
      tags:
        - always

    - name: Record Attempts to Alter Logon and Logout Events - faillock - Check if watch
        rule for {{ var_accounts_passwords_pam_faillock_dir }} already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+{{ var_accounts_passwords_pam_faillock_dir }}\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_faillock
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - faillock - Search /etc/audit/rules.d
        for other rules with specified key logins
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)logins$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_faillock
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - faillock - Use /etc/audit/rules.d/logins.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/logins.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_faillock
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - faillock - Use matched
        file as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_faillock
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - faillock - Add watch rule
        for {{ var_accounts_passwords_pam_faillock_dir }} in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w {{ var_accounts_passwords_pam_faillock_dir }} -p wa -k logins
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_faillock
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - faillock - Check if watch
        rule for {{ var_accounts_passwords_pam_faillock_dir }} already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+{{ var_accounts_passwords_pam_faillock_dir }}\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_faillock
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - faillock - Add watch rule
        for {{ var_accounts_passwords_pam_faillock_dir }} in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w {{ var_accounts_passwords_pam_faillock_dir }} -p wa -k logins
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_faillock
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Attempts to Alter Logon and Logout Events - lastlog [ref]
The audit system already collects login information for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /var/log/lastlog -p wa -k logins
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /var/log/lastlog -p wa -k logins
Rationale: | Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_login_events_lastlog
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.3
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218, SRG-OS-000470-GPOS-00214
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000503-CTR-001275, SRG-APP-000506-CTR-001290
anssi | R73
cis | 5.2.3.12
ism | 0582
pcidss4 | 10.2.1.3, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/var/log/lastlog" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/lastlog $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/var/log/lastlog$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /var/log/lastlog -p wa -k logins" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/logins.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/lastlog" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/logins.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/logins.rules"
        # If the logins.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/var/log/lastlog" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/lastlog $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/var/log/lastlog$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /var/log/lastlog -p wa -k logins" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_lastlog
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - lastlog - Check if watch
        rule for /var/log/lastlog already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/var/log/lastlog\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_lastlog
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - lastlog - Search /etc/audit/rules.d
        for other rules with specified key logins
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)logins$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_lastlog
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - lastlog - Use /etc/audit/rules.d/logins.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/logins.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_lastlog
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - lastlog - Use matched file
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_lastlog
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - lastlog - Add watch rule
        for /var/log/lastlog in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /var/log/lastlog -p wa -k logins
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_lastlog
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - lastlog - Check if watch
        rule for /var/log/lastlog already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/var/log/lastlog\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_lastlog
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter Logon and Logout Events - lastlog - Add watch rule
        for /var/log/lastlog in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /var/log/lastlog -p wa -k logins
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_rules_login_events_lastlog
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
Group Record Information on the Use of Privileged Commands Group contains 3 rules
[ref] At a minimum, the audit system should collect the execution of privileged commands for all users and root.
#### Rule Ensure auditd Collects Information on the Use of Privileged Commands [ref]
The audit system should collect information about usage of privileged commands for all users. These are commands with suid or sgid bits on and they are specially risky in local block device partitions not mounted with noexec and nosuid options. Therefore, these partitions should be first identified by the following command:
    findmnt -n -l -k -it $(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,) | grep -Pv "noexec|nosuid"
For all partitions listed by the previous command, it is necessary to search for setuid / setgid programs using the following command:
    $ sudo find PARTITION -xdev -perm /6000 -type f 2>/dev/null
For each setuid / setgid program identified by the previous command, an audit rule must be present in the appropriate place using the following line structure:
    -a always,exit -F path=PROG_PATH -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup, add the line to a file with suffix `.rules` in the `/etc/audit/rules.d` directory, replacing the PROG_PATH part with the full path of that setuid / setgid identified program. If the `auditd` daemon is configured to use the `auditctl` utility instead, add the line to the `/etc/audit/audit.rules` file, also replacing the PROG_PATH part with the full path of that setuid / setgid identified program. Warning: This rule checks for multiple syscalls related to privileged commands. If needed to check specific privileged commands, other more specific rules should be considered. For example: `audit_rules_privileged_commands_su` `audit_rules_privileged_commands_umount` `audit_rules_privileged_commands_passwd` Warning: Note that OVAL check and Bash / Ansible remediation of this rule explicitly excludes file systems mounted at `/proc` directory and its subdirectories. It is a virtual file system and it doesn't contain executable applications. At the same time, interacting with this file system during check or remediation caused undesirable errors.
Rationale: | Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern that can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_privileged_commands
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO08.04, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.05, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.5, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.3.4.5.9, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 3.9, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.1, A.16.1.2, A.16.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.3, A.6.2.1, A.6.2.2
nerc-cip | CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3
nist | AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-2, DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, DE.DP-4, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4, RS.CO-2
pcidss | Req-10.2.2
os-srg | SRG-OS-000327-GPOS-00127
anssi | R73
cis | 5.2.3.6
ism | 0582, 0846
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    ACTION_ARCH_FILTERS="-a always,exit"
    AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    SYSCALL=""
    KEY="privileged"
    SYSCALL_GROUPING=""

    function add_audit_rule()
    {
        local PRIV_CMD="$1"
        local OTHER_FILTERS="-F path=$PRIV_CMD -F perm=x"
        # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

        ACTION_ARCH_FILTERS="-a always,exit"
        unset syscall_a
        unset syscall_grouping
        unset syscall_string
        unset syscall
        unset file_to_edit
        unset rule_to_edit
        unset rule_syscalls_to_edit
        unset other_string
        unset auid_string
        unset full_rule

        # Load macro arguments into arrays
        read -a syscall_a <<< $SYSCALL
        read -a syscall_grouping <<< $SYSCALL_GROUPING

        # Create a list of audit *.rules files that should be inspected for presence and correctness
        # of a particular audit rule. The scheme is as follows:
        #
        # -----------------------------------------------------------------------------------------
        #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
        # -----------------------------------------------------------------------------------------
        #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
        # -----------------------------------------------------------------------------------------
        #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
        #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
        # -----------------------------------------------------------------------------------------
        #
        files_to_inspect=()

        # If audit tool is 'augenrules', then check if the audit rule is defined
        # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
        # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
        default_file="/etc/audit/rules.d/$KEY.rules"
        # As other_filters may include paths, lets use a different delimiter for it
        # The "F" script expression tells sed to print the filenames where the expressions matched
        readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
        # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
        if [ ${#files_to_inspect[@]} -eq "0" ]
        then
            file_to_inspect="/etc/audit/rules.d/$KEY.rules"
            files_to_inspect=("$file_to_inspect")
            if [ ! -e "$file_to_inspect" ]
            then
                touch "$file_to_inspect"
                chmod 0600 "$file_to_inspect"
            fi
        fi

        # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
        skip=1

        for audit_file in "${files_to_inspect[@]}"
        do
            # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
            # i.e, collect rules that match:
            # * the action, list and arch, (2-nd argument)
            # * the other filters, (3-rd argument)
            # * the auid filters, (4-rd argument)
            readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

            candidate_rules=()
            # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
            for s_rule in "${similar_rules[@]}"
            do
                # Strip all the options and fields we know of,
                # than check if there was any field left over
                extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
                grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
            done

            if [[ ${#syscall_a[@]} -ge 1 ]]
            then
                # Check if the syscall we want is present in any of the similar existing rules
                for rule in "${candidate_rules[@]}"
                do
                    rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                    all_syscalls_found=0
                    for syscall in "${syscall_a[@]}"
                    do
                        grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                           # A syscall was not found in the candidate rule
                           all_syscalls_found=1
                           }
                    done
                    if [[ $all_syscalls_found -eq 0 ]]
                    then
                        # We found a rule with all the syscall(s) we want; skip rest of macro
                        skip=0
                        break
                    fi

                    # Check if this rule can be grouped with our target syscall and keep track of it
                    for syscall_g in "${syscall_grouping[@]}"
                    do
                        if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                        then
                            file_to_edit=${audit_file}
                            rule_to_edit=${rule}
                            rule_syscalls_to_edit=${rule_syscalls}
                        fi
                    done
                done
            else
                # If there is any candidate rule, it is compliant; skip rest of macro
                if [ "${#candidate_rules[@]}" -gt 0 ]
                then
                    skip=0
                fi
            fi

            if [ "$skip" -eq 0 ]; then
                break
            fi
        done

        if [ "$skip" -ne 0 ]; then
            # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
            # At this point we know if we need to either append the $full_rule or group
            # the syscall together with an exsiting rule

            # Append the full_rule if it cannot be grouped to any other rule
            if [ -z ${rule_to_edit+x} ]
            then
                # Build full_rule while avoid adding double spaces when other_filters is empty
                if [ "${#syscall_a[@]}" -gt 0 ]
                then
                    syscall_string=""
                    for syscall in "${syscall_a[@]}"
                    do
                        syscall_string+=" -S $syscall"
                    done
                fi
                other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
                auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
                full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
                echo "$full_rule" >> "$default_file"
                chmod 0600 ${default_file}
            else
                # Check if the syscalls are declared as a comma separated list or
                # as multiple -S parameters
                if grep -q -- "," <<< "${rule_syscalls_to_edit}"
                then
                    delimiter=","
                else
                    delimiter=" -S "
                fi
                new_grouped_syscalls="${rule_syscalls_to_edit}"
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                       # A syscall was not found in the candidate rule
                       new_grouped_syscalls+="${delimiter}${syscall}"
                       }
                done

                # Group the syscall in the rule
                sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
            fi
        fi
        unset syscall_a
        unset syscall_grouping
        unset syscall_string
        unset syscall
        unset file_to_edit
        unset rule_to_edit
        unset rule_syscalls_to_edit
        unset other_string
        unset auid_string
        unset full_rule

        # Load macro arguments into arrays
        read -a syscall_a <<< $SYSCALL
        read -a syscall_grouping <<< $SYSCALL_GROUPING

        # Create a list of audit *.rules files that should be inspected for presence and correctness
        # of a particular audit rule. The scheme is as follows:
        #
        # -----------------------------------------------------------------------------------------
        #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
        # -----------------------------------------------------------------------------------------
        #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
        # -----------------------------------------------------------------------------------------
        #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
        #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
        # -----------------------------------------------------------------------------------------
        #
        files_to_inspect=()

        # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
        # file to the list of files to be inspected
        default_file="/etc/audit/audit.rules"
        files_to_inspect+=('/etc/audit/audit.rules' )

        # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
        skip=1

        for audit_file in "${files_to_inspect[@]}"
        do
            # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
            # i.e, collect rules that match:
            # * the action, list and arch, (2-nd argument)
            # * the other filters, (3-rd argument)
            # * the auid filters, (4-rd argument)
            readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

            candidate_rules=()
            # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
            for s_rule in "${similar_rules[@]}"
            do
                # Strip all the options and fields we know of,
                # than check if there was any field left over
                extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
                grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
            done

            if [[ ${#syscall_a[@]} -ge 1 ]]
            then
                # Check if the syscall we want is present in any of the similar existing rules
                for rule in "${candidate_rules[@]}"
                do
                    rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                    all_syscalls_found=0
                    for syscall in "${syscall_a[@]}"
                    do
                        grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                           # A syscall was not found in the candidate rule
                           all_syscalls_found=1
                           }
                    done
                    if [[ $all_syscalls_found -eq 0 ]]
                    then
                        # We found a rule with all the syscall(s) we want; skip rest of macro
                        skip=0
                        break
                    fi

                    # Check if this rule can be grouped with our target syscall and keep track of it
                    for syscall_g in "${syscall_grouping[@]}"
                    do
                        if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                        then
                            file_to_edit=${audit_file}
                            rule_to_edit=${rule}
                            rule_syscalls_to_edit=${rule_syscalls}
                        fi
                    done
                done
            else
                # If there is any candidate rule, it is compliant; skip rest of macro
                if [ "${#candidate_rules[@]}" -gt 0 ]
                then
                    skip=0
                fi
            fi

            if [ "$skip" -eq 0 ]; then
                break
            fi
        done

        if [ "$skip" -ne 0 ]; then
            # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
            # At this point we know if we need to either append the $full_rule or group
            # the syscall together with an exsiting rule

            # Append the full_rule if it cannot be grouped to any other rule
            if [ -z ${rule_to_edit+x} ]
            then
                # Build full_rule while avoid adding double spaces when other_filters is empty
                if [ "${#syscall_a[@]}" -gt 0 ]
                then
                    syscall_string=""
                    for syscall in "${syscall_a[@]}"
                    do
                        syscall_string+=" -S $syscall"
                    done
                fi
                other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
                auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
                full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
                echo "$full_rule" >> "$default_file"
                chmod 0600 ${default_file}
            else
                # Check if the syscalls are declared as a comma separated list or
                # as multiple -S parameters
                if grep -q -- "," <<< "${rule_syscalls_to_edit}"
                then
                    delimiter=","
                else
                    delimiter=" -S "
                fi
                new_grouped_syscalls="${rule_syscalls_to_edit}"
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                       # A syscall was not found in the candidate rule
                       new_grouped_syscalls+="${delimiter}${syscall}"
                       }
                done

                # Group the syscall in the rule
                sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
            fi
        fi

    }

    if { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
      PRIV_CMDS=$(find / -perm /6000 -type f -not -path "/sysroot/*" 2>/dev/null)
      for PRIV_CMD in $PRIV_CMDS; do
        add_audit_rule $PRIV_CMD
      done
    else
      FILTER_NODEV=$(awk '/nodev/ { print $2 }' /proc/filesystems | paste -sd,)
      PARTITIONS=$(findmnt -n -l -k -it "$FILTER_NODEV" | grep -Pv "noexec|nosuid|/proc($|/.*$)" | awk '{ print $1 }')
      for PARTITION in $PARTITIONS; do
        PRIV_CMDS=$(find "${PARTITION}" -xdev -perm /6000 -type f 2>/dev/null)
        for PRIV_CMD in $PRIV_CMDS; do
          add_audit_rule $PRIV_CMD
        done
      done
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - audit_rules_privileged_commands
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on the Use of Privileged Commands - Set
        List of Mount Points Which Permits Execution of Privileged Commands
      ansible.builtin.set_fact:
        privileged_mount_points: '{{ (ansible_facts.mounts | rejectattr(''options'', ''search'',
          ''noexec|nosuid'') | rejectattr(''mount'', ''match'', ''/proc($|/.*$)'') | map(attribute=''mount'')
          | list ) }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - audit_rules_privileged_commands
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on the Use of Privileged Commands - Search
        for Privileged Commands in Eligible Mount Points
      ansible.builtin.shell:
        cmd: find {{ item }} -xdev -perm /6000 -type f 2>/dev/null
      register: result_privileged_commands_search
      changed_when: false
      failed_when: false
      with_items: '{{ privileged_mount_points }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - audit_rules_privileged_commands
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on the Use of Privileged Commands - Set
        List of Privileged Commands Found in Eligible Mount Points
      ansible.builtin.set_fact:
        privileged_commands: '{{ privileged_commands | default([]) + item.stdout_lines
          }}'
      loop: '{{ result_privileged_commands_search.results }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - item is not skipped
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - audit_rules_privileged_commands
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure auditd Collects Information on the Use of Privileged Commands - Privileged
        Commands are Present in the System
      block:

      - name: Ensure auditd Collects Information on the Use of Privileged Commands - Ensure
          Rules for All Privileged Commands in augenrules Format
        ansible.builtin.lineinfile:
          path: /etc/audit/rules.d/privileged.rules
          line: -a always,exit -F path={{ item }} -F perm=x -F auid>=1000 -F auid!=unset
            -F key=privileged
          regexp: ^.*path={{ item | regex_escape() }} .*$
          create: true
        with_items:
        - '{{ privileged_commands }}'

      - name: Ensure auditd Collects Information on the Use of Privileged Commands - Ensure
          Rules for All Privileged Commands in auditctl Format
        ansible.builtin.lineinfile:
          path: /etc/audit/audit.rules
          line: -a always,exit -F path={{ item }} -F perm=x -F auid>=1000 -F auid!=unset
            -F key=privileged
          regexp: ^.*path={{ item | regex_escape() }} .*$
          create: true
        with_items:
        - '{{ privileged_commands }}'

      - name: Ensure auditd Collects Information on the Use of Privileged Commands - Search
          for Duplicated Rules in Other Files
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          recurse: false
          contains: ^-a always,exit (-F arch=b32 |-F arch=b64 )?-F path={{ item | regex_escape()
            }} .*$
          patterns: '*.rules'
        with_items:
        - '{{ privileged_commands }}'
        register: result_augenrules_files

      - name: Ensure auditd Collects Information on the Use of Privileged Commands - Ensure
          Rules for Privileged Commands are Defined Only in One File
        ansible.builtin.lineinfile:
          path: '{{ item.1.path }}'
          regexp: ^-a always,exit (-F arch=b32 |-F arch=b64 )?-F path={{ item.0.item |
            regex_escape() }} .*$
          state: absent
        with_subelements:
        - '{{ result_augenrules_files.results }}'
        - files
        when:
        - item.1.path != '/etc/audit/rules.d/privileged.rules'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - privileged_commands is defined
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - audit_rules_privileged_commands
      - configure_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Ensure auditd Collects Information on the Use of Privileged Commands - kmod [ref]
At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/bin/kmod -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/bin/kmod -F auid>=1000 -F auid!=unset -F key=privileged
Rationale: | Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_privileged_commands_kmod
References: |
nist | AU-3, AU-3.1, AU-12(a), AU-12.1(ii), AU-12.1(iv)AU-12(c), MA-4(1)(a)
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000471-GPOS-00216, SRG-OS-000477-GPOS-00222
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000504-CTR-001280
anssi | R73
cis | 5.2.3.19
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Retrieve hardware architecture of the underlying system
    OTHER_FILTERS="-F path=/usr/bin/kmod"
    AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    SYSCALL=""
    KEY="privileged"
    SYSCALL_GROUPING=""

    ACTION_ARCH_FILTERS="-a always,exit"
    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AU-12(a)
      - NIST-800-53-AU-12.1(ii)
      - NIST-800-53-AU-12.1(iv)AU-12(c)
      - NIST-800-53-AU-3
      - NIST-800-53-AU-3.1
      - NIST-800-53-MA-4(1)(a)
      - audit_rules_privileged_commands_kmod
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects Information on the Use of Privileged Commands - kmod
        - Perform remediation of Audit rules for /usr/bin/kmod
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls: []
          syscall_grouping: []

      - name: Check existence of  in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
            path=/usr/bin/kmod -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/bin/kmod -F auid>=1000
            -F auid!=unset (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/kmod -F auid>=1000
            -F auid!=unset -F key=privileged
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls: []
          syscall_grouping: []

      - name: Check existence of  in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
            path=/usr/bin/kmod -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
            -S |,)\w+)+)( -F path=/usr/bin/kmod -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/bin/kmod -F auid>=1000
            -F auid!=unset -F key=privileged
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AU-12(a)
      - NIST-800-53-AU-12.1(ii)
      - NIST-800-53-AU-12.1(iv)AU-12(c)
      - NIST-800-53-AU-3
      - NIST-800-53-AU-3.1
      - NIST-800-53-MA-4(1)(a)
      - audit_rules_privileged_commands_kmod
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure auditd Collects Information on the Use of Privileged Commands - usermod [ref]
At a minimum, the audit system should collect the execution of privileged commands for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add a line of the following form to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F path=/usr/sbin/usermod -F auid>=1000 -F auid!=unset -F key=privileged
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add a line of the following form to `/etc/audit/audit.rules`:
    -a always,exit -F path=/usr/sbin/usermod -F auid>=1000 -F auid!=unset -F key=privileged
Rationale: | Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider and advanced persistent threats. Privileged programs are subject to escalation-of-privilege attacks, which attempt to subvert their normal role of providing some necessary but limited capability. As such, motivation exists to monitor these programs for unusual activity.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_privileged_commands_usermod
References: |
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000466-GPOS-00210
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255
cis | 5.2.3.18
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Retrieve hardware architecture of the underlying system
    OTHER_FILTERS="-F path=/usr/sbin/usermod"
    AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    SYSCALL=""
    KEY="privileged"
    SYSCALL_GROUPING=""

    ACTION_ARCH_FILTERS="-a always,exit"
    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - audit_rules_privileged_commands_usermod
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects Information on the Use of Privileged Commands - usermod
        - Perform remediation of Audit rules for /usr/sbin/usermod
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls: []
          syscall_grouping: []

      - name: Check existence of  in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
            path=/usr/sbin/usermod -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/privileged.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/privileged.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F path=/usr/sbin/usermod -F auid>=1000
            -F auid!=unset (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/sbin/usermod -F
            auid>=1000 -F auid!=unset -F key=privileged
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls: []
          syscall_grouping: []

      - name: Check existence of  in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit(( -S |,)\w+)*(( -S |,){{ item }})+(( -S |,)\w+)* -F
            path=/usr/sbin/usermod -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit)(?=.*(?:(?:-S |,)(?:{{ syscalls_found | join("|") }}))\b)((?:(
            -S |,)\w+)+)( -F path=/usr/sbin/usermod -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit{{ syscalls | join(',') }} -F path=/usr/sbin/usermod -F
            auid>=1000 -F auid!=unset -F key=privileged
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - audit_rules_privileged_commands_usermod
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
Group Records Events that Modify Date and Time Information Group contains 5 rules
[ref] Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time. All changes to the system time should be audited.
#### Rule Record attempts to alter time through adjtimex [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S adjtimex -F key=audit_time_rules
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S adjtimex -F key=audit_time_rules
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S adjtimex -F key=audit_time_rules
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S adjtimex -F key=audit_time_rules
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
    -a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules
Rationale: | Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_time_adjtimex
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.4.2.b
anssi | R73
cis | 5.2.3.4
ism | 0582
pcidss4 | 10.6.3, 10.6
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
        # Create expected audit group and audit rule form for particular system call & architecture
        if [ ${ARCH} = "b32" ]
        then
            ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
            # stime system call is known at 32-bit arch (see e.g "$ ausyscall i386 stime" 's output)
            # so append it to the list of time group system calls to be audited
            SYSCALL="adjtimex settimeofday stime"
            SYSCALL_GROUPING="adjtimex settimeofday stime"
        elif [ ${ARCH} = "b64" ]
        then
            ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
            # stime system call isn't known at 64-bit arch (see "$ ausyscall x86_64 stime" 's output)
            # therefore don't add it to the list of time group system calls to be audited
            SYSCALL="adjtimex settimeofday"
            SYSCALL_GROUPING="adjtimex settimeofday"
        fi
        OTHER_FILTERS=""
        AUID_FILTERS=""
        KEY="audit_time_rules"
        # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
        unset syscall_a
        unset syscall_grouping
        unset syscall_string
        unset syscall
        unset file_to_edit
        unset rule_to_edit
        unset rule_syscalls_to_edit
        unset other_string
        unset auid_string
        unset full_rule

        # Load macro arguments into arrays
        read -a syscall_a <<< $SYSCALL
        read -a syscall_grouping <<< $SYSCALL_GROUPING

        # Create a list of audit *.rules files that should be inspected for presence and correctness
        # of a particular audit rule. The scheme is as follows:
        #
        # -----------------------------------------------------------------------------------------
        #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
        # -----------------------------------------------------------------------------------------
        #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
        # -----------------------------------------------------------------------------------------
        #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
        #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
        # -----------------------------------------------------------------------------------------
        #
        files_to_inspect=()

        # If audit tool is 'augenrules', then check if the audit rule is defined
        # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
        # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
        default_file="/etc/audit/rules.d/$KEY.rules"
        # As other_filters may include paths, lets use a different delimiter for it
        # The "F" script expression tells sed to print the filenames where the expressions matched
        readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
        # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
        if [ ${#files_to_inspect[@]} -eq "0" ]
        then
            file_to_inspect="/etc/audit/rules.d/$KEY.rules"
            files_to_inspect=("$file_to_inspect")
            if [ ! -e "$file_to_inspect" ]
            then
                touch "$file_to_inspect"
                chmod 0600 "$file_to_inspect"
            fi
        fi

        # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
        skip=1

        for audit_file in "${files_to_inspect[@]}"
        do
            # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
            # i.e, collect rules that match:
            # * the action, list and arch, (2-nd argument)
            # * the other filters, (3-rd argument)
            # * the auid filters, (4-rd argument)
            readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

            candidate_rules=()
            # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
            for s_rule in "${similar_rules[@]}"
            do
                # Strip all the options and fields we know of,
                # than check if there was any field left over
                extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
                grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
            done

            if [[ ${#syscall_a[@]} -ge 1 ]]
            then
                # Check if the syscall we want is present in any of the similar existing rules
                for rule in "${candidate_rules[@]}"
                do
                    rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                    all_syscalls_found=0
                    for syscall in "${syscall_a[@]}"
                    do
                        grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                           # A syscall was not found in the candidate rule
                           all_syscalls_found=1
                           }
                    done
                    if [[ $all_syscalls_found -eq 0 ]]
                    then
                        # We found a rule with all the syscall(s) we want; skip rest of macro
                        skip=0
                        break
                    fi

                    # Check if this rule can be grouped with our target syscall and keep track of it
                    for syscall_g in "${syscall_grouping[@]}"
                    do
                        if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                        then
                            file_to_edit=${audit_file}
                            rule_to_edit=${rule}
                            rule_syscalls_to_edit=${rule_syscalls}
                        fi
                    done
                done
            else
                # If there is any candidate rule, it is compliant; skip rest of macro
                if [ "${#candidate_rules[@]}" -gt 0 ]
                then
                    skip=0
                fi
            fi

            if [ "$skip" -eq 0 ]; then
                break
            fi
        done

        if [ "$skip" -ne 0 ]; then
            # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
            # At this point we know if we need to either append the $full_rule or group
            # the syscall together with an exsiting rule

            # Append the full_rule if it cannot be grouped to any other rule
            if [ -z ${rule_to_edit+x} ]
            then
                # Build full_rule while avoid adding double spaces when other_filters is empty
                if [ "${#syscall_a[@]}" -gt 0 ]
                then
                    syscall_string=""
                    for syscall in "${syscall_a[@]}"
                    do
                        syscall_string+=" -S $syscall"
                    done
                fi
                other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
                auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
                full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
                echo "$full_rule" >> "$default_file"
                chmod 0600 ${default_file}
            else
                # Check if the syscalls are declared as a comma separated list or
                # as multiple -S parameters
                if grep -q -- "," <<< "${rule_syscalls_to_edit}"
                then
                    delimiter=","
                else
                    delimiter=" -S "
                fi
                new_grouped_syscalls="${rule_syscalls_to_edit}"
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                       # A syscall was not found in the candidate rule
                       new_grouped_syscalls+="${delimiter}${syscall}"
                       }
                done

                # Group the syscall in the rule
                sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
            fi
        fi
        unset syscall_a
        unset syscall_grouping
        unset syscall_string
        unset syscall
        unset file_to_edit
        unset rule_to_edit
        unset rule_syscalls_to_edit
        unset other_string
        unset auid_string
        unset full_rule

        # Load macro arguments into arrays
        read -a syscall_a <<< $SYSCALL
        read -a syscall_grouping <<< $SYSCALL_GROUPING

        # Create a list of audit *.rules files that should be inspected for presence and correctness
        # of a particular audit rule. The scheme is as follows:
        #
        # -----------------------------------------------------------------------------------------
        #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
        # -----------------------------------------------------------------------------------------
        #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
        # -----------------------------------------------------------------------------------------
        #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
        #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
        # -----------------------------------------------------------------------------------------
        #
        files_to_inspect=()

        # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
        # file to the list of files to be inspected
        default_file="/etc/audit/audit.rules"
        files_to_inspect+=('/etc/audit/audit.rules' )

        # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
        skip=1

        for audit_file in "${files_to_inspect[@]}"
        do
            # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
            # i.e, collect rules that match:
            # * the action, list and arch, (2-nd argument)
            # * the other filters, (3-rd argument)
            # * the auid filters, (4-rd argument)
            readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

            candidate_rules=()
            # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
            for s_rule in "${similar_rules[@]}"
            do
                # Strip all the options and fields we know of,
                # than check if there was any field left over
                extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
                grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
            done

            if [[ ${#syscall_a[@]} -ge 1 ]]
            then
                # Check if the syscall we want is present in any of the similar existing rules
                for rule in "${candidate_rules[@]}"
                do
                    rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                    all_syscalls_found=0
                    for syscall in "${syscall_a[@]}"
                    do
                        grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                           # A syscall was not found in the candidate rule
                           all_syscalls_found=1
                           }
                    done
                    if [[ $all_syscalls_found -eq 0 ]]
                    then
                        # We found a rule with all the syscall(s) we want; skip rest of macro
                        skip=0
                        break
                    fi

                    # Check if this rule can be grouped with our target syscall and keep track of it
                    for syscall_g in "${syscall_grouping[@]}"
                    do
                        if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                        then
                            file_to_edit=${audit_file}
                            rule_to_edit=${rule}
                            rule_syscalls_to_edit=${rule_syscalls}
                        fi
                    done
                done
            else
                # If there is any candidate rule, it is compliant; skip rest of macro
                if [ "${#candidate_rules[@]}" -gt 0 ]
                then
                    skip=0
                fi
            fi

            if [ "$skip" -eq 0 ]; then
                break
            fi
        done

        if [ "$skip" -ne 0 ]; then
            # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
            # At this point we know if we need to either append the $full_rule or group
            # the syscall together with an exsiting rule

            # Append the full_rule if it cannot be grouped to any other rule
            if [ -z ${rule_to_edit+x} ]
            then
                # Build full_rule while avoid adding double spaces when other_filters is empty
                if [ "${#syscall_a[@]}" -gt 0 ]
                then
                    syscall_string=""
                    for syscall in "${syscall_a[@]}"
                    do
                        syscall_string+=" -S $syscall"
                    done
                fi
                other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
                auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
                full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
                echo "$full_rule" >> "$default_file"
                chmod 0600 ${default_file}
            else
                # Check if the syscalls are declared as a comma separated list or
                # as multiple -S parameters
                if grep -q -- "," <<< "${rule_syscalls_to_edit}"
                then
                    delimiter=","
                else
                    delimiter=" -S "
                fi
                new_grouped_syscalls="${rule_syscalls_to_edit}"
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                       # A syscall was not found in the candidate rule
                       new_grouped_syscalls+="${delimiter}${syscall}"
                       }
                done

                # Group the syscall in the rule
                sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
            fi
        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_adjtimex
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set architecture for audit tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_adjtimex
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Perform remediation of Audit rules for adjtimex for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - adjtimex
          syscall_grouping:
          - adjtimex
          - settimeofday
          - stime

      - name: Check existence of adjtimex in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - adjtimex
          syscall_grouping:
          - adjtimex
          - settimeofday
          - stime

      - name: Check existence of adjtimex in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_adjtimex
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Perform remediation of Audit rules for adjtimex for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - adjtimex
          syscall_grouping:
          - adjtimex
          - settimeofday

      - name: Check existence of adjtimex in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_time_rules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - adjtimex
          syscall_grouping:
          - adjtimex
          - settimeofday
          - stime

      - name: Check existence of adjtimex in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_time_rules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_adjtimex
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Attempts to Alter Time Through clock_settime [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S clock_settime -F a0=0x0 -F key=time-change
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -F key=time-change
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S clock_settime -F a0=0x0 -F key=time-change
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S clock_settime -F a0=0x0 -F key=time-change
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
    -a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules
Rationale: | Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_time_clock_settime
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.4.2.b
anssi | R73
cis | 5.2.3.4
ism | 0582
pcidss4 | 10.6.3, 10.6
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS="-F a0=0x0"
    	AUID_FILTERS=""
    	SYSCALL="clock_settime"
    	KEY="time-change"
    	SYSCALL_GROUPING=""
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_clock_settime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set architecture for audit tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_clock_settime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Perform remediation of Audit rules for clock_settime for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - clock_settime
          syscall_grouping: []

      - name: Check existence of clock_settime in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F a0=0x0 (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/time-change.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/time-change.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F a0=0x0 (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F a0=0x0 -F
            key=time-change
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - clock_settime
          syscall_grouping: []

      - name: Check existence of clock_settime in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F a0=0x0 (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F a0=0x0 (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F a0=0x0 -F
            key=time-change
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_clock_settime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Perform remediation of Audit rules for clock_settime for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - clock_settime
          syscall_grouping: []

      - name: Check existence of clock_settime in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F a0=0x0 (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/time-change.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/time-change.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F a0=0x0 (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F a0=0x0 -F
            key=time-change
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - clock_settime
          syscall_grouping: []

      - name: Check existence of clock_settime in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F a0=0x0 (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F a0=0x0 (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F a0=0x0 -F
            key=time-change
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_clock_settime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record attempts to alter time through settimeofday [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -a always,exit -F arch=b32 -S settimeofday -F key=audit_time_rules
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S settimeofday -F key=audit_time_rules
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -a always,exit -F arch=b32 -S settimeofday -F key=audit_time_rules
If the system is 64 bit then also add the following line:
    -a always,exit -F arch=b64 -S settimeofday -F key=audit_time_rules
The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined syscalls:
    -a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules
Rationale: | Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_time_settimeofday
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.4.2.b
cis | 5.2.3.4
ism | 0582
pcidss4 | 10.6.3, 10.6
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
        # Create expected audit group and audit rule form for particular system call & architecture
        if [ ${ARCH} = "b32" ]
        then
            ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
            # stime system call is known at 32-bit arch (see e.g "$ ausyscall i386 stime" 's output)
            # so append it to the list of time group system calls to be audited
            SYSCALL="adjtimex settimeofday stime"
            SYSCALL_GROUPING="adjtimex settimeofday stime"
        elif [ ${ARCH} = "b64" ]
        then
            ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
            # stime system call isn't known at 64-bit arch (see "$ ausyscall x86_64 stime" 's output)
            # therefore don't add it to the list of time group system calls to be audited
            SYSCALL="adjtimex settimeofday"
            SYSCALL_GROUPING="adjtimex settimeofday"
        fi
        OTHER_FILTERS=""
        AUID_FILTERS=""
        KEY="audit_time_rules"
        # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
        unset syscall_a
        unset syscall_grouping
        unset syscall_string
        unset syscall
        unset file_to_edit
        unset rule_to_edit
        unset rule_syscalls_to_edit
        unset other_string
        unset auid_string
        unset full_rule

        # Load macro arguments into arrays
        read -a syscall_a <<< $SYSCALL
        read -a syscall_grouping <<< $SYSCALL_GROUPING

        # Create a list of audit *.rules files that should be inspected for presence and correctness
        # of a particular audit rule. The scheme is as follows:
        #
        # -----------------------------------------------------------------------------------------
        #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
        # -----------------------------------------------------------------------------------------
        #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
        # -----------------------------------------------------------------------------------------
        #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
        #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
        # -----------------------------------------------------------------------------------------
        #
        files_to_inspect=()

        # If audit tool is 'augenrules', then check if the audit rule is defined
        # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
        # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
        default_file="/etc/audit/rules.d/$KEY.rules"
        # As other_filters may include paths, lets use a different delimiter for it
        # The "F" script expression tells sed to print the filenames where the expressions matched
        readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
        # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
        if [ ${#files_to_inspect[@]} -eq "0" ]
        then
            file_to_inspect="/etc/audit/rules.d/$KEY.rules"
            files_to_inspect=("$file_to_inspect")
            if [ ! -e "$file_to_inspect" ]
            then
                touch "$file_to_inspect"
                chmod 0600 "$file_to_inspect"
            fi
        fi

        # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
        skip=1

        for audit_file in "${files_to_inspect[@]}"
        do
            # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
            # i.e, collect rules that match:
            # * the action, list and arch, (2-nd argument)
            # * the other filters, (3-rd argument)
            # * the auid filters, (4-rd argument)
            readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

            candidate_rules=()
            # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
            for s_rule in "${similar_rules[@]}"
            do
                # Strip all the options and fields we know of,
                # than check if there was any field left over
                extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
                grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
            done

            if [[ ${#syscall_a[@]} -ge 1 ]]
            then
                # Check if the syscall we want is present in any of the similar existing rules
                for rule in "${candidate_rules[@]}"
                do
                    rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                    all_syscalls_found=0
                    for syscall in "${syscall_a[@]}"
                    do
                        grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                           # A syscall was not found in the candidate rule
                           all_syscalls_found=1
                           }
                    done
                    if [[ $all_syscalls_found -eq 0 ]]
                    then
                        # We found a rule with all the syscall(s) we want; skip rest of macro
                        skip=0
                        break
                    fi

                    # Check if this rule can be grouped with our target syscall and keep track of it
                    for syscall_g in "${syscall_grouping[@]}"
                    do
                        if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                        then
                            file_to_edit=${audit_file}
                            rule_to_edit=${rule}
                            rule_syscalls_to_edit=${rule_syscalls}
                        fi
                    done
                done
            else
                # If there is any candidate rule, it is compliant; skip rest of macro
                if [ "${#candidate_rules[@]}" -gt 0 ]
                then
                    skip=0
                fi
            fi

            if [ "$skip" -eq 0 ]; then
                break
            fi
        done

        if [ "$skip" -ne 0 ]; then
            # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
            # At this point we know if we need to either append the $full_rule or group
            # the syscall together with an exsiting rule

            # Append the full_rule if it cannot be grouped to any other rule
            if [ -z ${rule_to_edit+x} ]
            then
                # Build full_rule while avoid adding double spaces when other_filters is empty
                if [ "${#syscall_a[@]}" -gt 0 ]
                then
                    syscall_string=""
                    for syscall in "${syscall_a[@]}"
                    do
                        syscall_string+=" -S $syscall"
                    done
                fi
                other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
                auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
                full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
                echo "$full_rule" >> "$default_file"
                chmod 0600 ${default_file}
            else
                # Check if the syscalls are declared as a comma separated list or
                # as multiple -S parameters
                if grep -q -- "," <<< "${rule_syscalls_to_edit}"
                then
                    delimiter=","
                else
                    delimiter=" -S "
                fi
                new_grouped_syscalls="${rule_syscalls_to_edit}"
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                       # A syscall was not found in the candidate rule
                       new_grouped_syscalls+="${delimiter}${syscall}"
                       }
                done

                # Group the syscall in the rule
                sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
            fi
        fi
        unset syscall_a
        unset syscall_grouping
        unset syscall_string
        unset syscall
        unset file_to_edit
        unset rule_to_edit
        unset rule_syscalls_to_edit
        unset other_string
        unset auid_string
        unset full_rule

        # Load macro arguments into arrays
        read -a syscall_a <<< $SYSCALL
        read -a syscall_grouping <<< $SYSCALL_GROUPING

        # Create a list of audit *.rules files that should be inspected for presence and correctness
        # of a particular audit rule. The scheme is as follows:
        #
        # -----------------------------------------------------------------------------------------
        #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
        # -----------------------------------------------------------------------------------------
        #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
        # -----------------------------------------------------------------------------------------
        #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
        #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
        # -----------------------------------------------------------------------------------------
        #
        files_to_inspect=()

        # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
        # file to the list of files to be inspected
        default_file="/etc/audit/audit.rules"
        files_to_inspect+=('/etc/audit/audit.rules' )

        # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
        skip=1

        for audit_file in "${files_to_inspect[@]}"
        do
            # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
            # i.e, collect rules that match:
            # * the action, list and arch, (2-nd argument)
            # * the other filters, (3-rd argument)
            # * the auid filters, (4-rd argument)
            readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

            candidate_rules=()
            # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
            for s_rule in "${similar_rules[@]}"
            do
                # Strip all the options and fields we know of,
                # than check if there was any field left over
                extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
                grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
            done

            if [[ ${#syscall_a[@]} -ge 1 ]]
            then
                # Check if the syscall we want is present in any of the similar existing rules
                for rule in "${candidate_rules[@]}"
                do
                    rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                    all_syscalls_found=0
                    for syscall in "${syscall_a[@]}"
                    do
                        grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                           # A syscall was not found in the candidate rule
                           all_syscalls_found=1
                           }
                    done
                    if [[ $all_syscalls_found -eq 0 ]]
                    then
                        # We found a rule with all the syscall(s) we want; skip rest of macro
                        skip=0
                        break
                    fi

                    # Check if this rule can be grouped with our target syscall and keep track of it
                    for syscall_g in "${syscall_grouping[@]}"
                    do
                        if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                        then
                            file_to_edit=${audit_file}
                            rule_to_edit=${rule}
                            rule_syscalls_to_edit=${rule_syscalls}
                        fi
                    done
                done
            else
                # If there is any candidate rule, it is compliant; skip rest of macro
                if [ "${#candidate_rules[@]}" -gt 0 ]
                then
                    skip=0
                fi
            fi

            if [ "$skip" -eq 0 ]; then
                break
            fi
        done

        if [ "$skip" -ne 0 ]; then
            # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
            # At this point we know if we need to either append the $full_rule or group
            # the syscall together with an exsiting rule

            # Append the full_rule if it cannot be grouped to any other rule
            if [ -z ${rule_to_edit+x} ]
            then
                # Build full_rule while avoid adding double spaces when other_filters is empty
                if [ "${#syscall_a[@]}" -gt 0 ]
                then
                    syscall_string=""
                    for syscall in "${syscall_a[@]}"
                    do
                        syscall_string+=" -S $syscall"
                    done
                fi
                other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
                auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
                full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
                echo "$full_rule" >> "$default_file"
                chmod 0600 ${default_file}
            else
                # Check if the syscalls are declared as a comma separated list or
                # as multiple -S parameters
                if grep -q -- "," <<< "${rule_syscalls_to_edit}"
                then
                    delimiter=","
                else
                    delimiter=" -S "
                fi
                new_grouped_syscalls="${rule_syscalls_to_edit}"
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                       # A syscall was not found in the candidate rule
                       new_grouped_syscalls+="${delimiter}${syscall}"
                       }
                done

                # Group the syscall in the rule
                sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
            fi
        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_settimeofday
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set architecture for audit tasks
      set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_settimeofday
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Perform remediation of Audit rules for settimeofday for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - settimeofday
          syscall_grouping:
          - adjtimex
          - settimeofday
          - stime

      - name: Check existence of settimeofday in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - settimeofday
          syscall_grouping:
          - adjtimex
          - settimeofday
          - stime

      - name: Check existence of settimeofday in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_settimeofday
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Perform remediation of Audit rules for settimeofday for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - settimeofday
          syscall_grouping:
          - adjtimex
          - settimeofday
          - stime

      - name: Check existence of settimeofday in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_time_rules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - settimeofday
          syscall_grouping:
          - adjtimex
          - settimeofday
          - stime

      - name: Check existence of settimeofday in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_time_rules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_settimeofday
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Attempts to Alter Time Through stime [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d` for both 32 bit and 64 bit systems:
    -a always,exit -F arch=b32 -S stime -F key=audit_time_rules
Since the 64 bit version of the "stime" system call is not defined in the audit lookup table, the corresponding "-F arch=b64" form of this rule is not expected to be defined on 64 bit systems (the aforementioned "-F arch=b32" stime rule form itself is sufficient for both 32 bit and 64 bit systems). If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file for both 32 bit and 64 bit systems:
    -a always,exit -F arch=b32 -S stime -F key=audit_time_rules
Since the 64 bit version of the "stime" system call is not defined in the audit lookup table, the corresponding "-F arch=b64" form of this rule is not expected to be defined on 64 bit systems (the aforementioned "-F arch=b32" stime rule form itself is sufficient for both 32 bit and 64 bit systems). The -k option allows for the specification of a key in string form that can be used for better reporting capability through ausearch and aureport. Multiple system calls can be defined on the same line to save space if desired, but is not required. See an example of multiple combined system calls:
    -a always,exit -F arch=b64 -S adjtimex,settimeofday -F key=audit_time_rules
Rationale: | Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_time_stime
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.4.2.b
anssi | R73
cis | 5.2.3.4
ism | 0582
pcidss4 | 10.6.3, 10.6
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel && { ( ( ! ( ( grep -sqE "^.*\.aarch64$" /proc/sys/kernel/osrelease || grep -sqE "^aarch64$" /proc/sys/kernel/arch; ) ) && ! ( ( grep -sqE "^.*\.s390x$" /proc/sys/kernel/osrelease || grep -sqE "^s390x$" /proc/sys/kernel/arch; ) ) ) ); }; then

    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
        # Create expected audit group and audit rule form for particular system call & architecture
        if [ ${ARCH} = "b32" ]
        then
            ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
            # stime system call is known at 32-bit arch (see e.g "$ ausyscall i386 stime" 's output)
            # so append it to the list of time group system calls to be audited
            SYSCALL="adjtimex settimeofday stime"
            SYSCALL_GROUPING="adjtimex settimeofday stime"
        elif [ ${ARCH} = "b64" ]
        then
            ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
            # stime system call isn't known at 64-bit arch (see "$ ausyscall x86_64 stime" 's output)
            # therefore don't add it to the list of time group system calls to be audited
            SYSCALL="adjtimex settimeofday"
            SYSCALL_GROUPING="adjtimex settimeofday"
        fi
        OTHER_FILTERS=""
        AUID_FILTERS=""
        KEY="audit_time_rules"
        # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
        unset syscall_a
        unset syscall_grouping
        unset syscall_string
        unset syscall
        unset file_to_edit
        unset rule_to_edit
        unset rule_syscalls_to_edit
        unset other_string
        unset auid_string
        unset full_rule

        # Load macro arguments into arrays
        read -a syscall_a <<< $SYSCALL
        read -a syscall_grouping <<< $SYSCALL_GROUPING

        # Create a list of audit *.rules files that should be inspected for presence and correctness
        # of a particular audit rule. The scheme is as follows:
        #
        # -----------------------------------------------------------------------------------------
        #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
        # -----------------------------------------------------------------------------------------
        #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
        # -----------------------------------------------------------------------------------------
        #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
        #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
        # -----------------------------------------------------------------------------------------
        #
        files_to_inspect=()

        # If audit tool is 'augenrules', then check if the audit rule is defined
        # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
        # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
        default_file="/etc/audit/rules.d/$KEY.rules"
        # As other_filters may include paths, lets use a different delimiter for it
        # The "F" script expression tells sed to print the filenames where the expressions matched
        readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
        # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
        if [ ${#files_to_inspect[@]} -eq "0" ]
        then
            file_to_inspect="/etc/audit/rules.d/$KEY.rules"
            files_to_inspect=("$file_to_inspect")
            if [ ! -e "$file_to_inspect" ]
            then
                touch "$file_to_inspect"
                chmod 0600 "$file_to_inspect"
            fi
        fi

        # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
        skip=1

        for audit_file in "${files_to_inspect[@]}"
        do
            # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
            # i.e, collect rules that match:
            # * the action, list and arch, (2-nd argument)
            # * the other filters, (3-rd argument)
            # * the auid filters, (4-rd argument)
            readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

            candidate_rules=()
            # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
            for s_rule in "${similar_rules[@]}"
            do
                # Strip all the options and fields we know of,
                # than check if there was any field left over
                extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
                grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
            done

            if [[ ${#syscall_a[@]} -ge 1 ]]
            then
                # Check if the syscall we want is present in any of the similar existing rules
                for rule in "${candidate_rules[@]}"
                do
                    rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                    all_syscalls_found=0
                    for syscall in "${syscall_a[@]}"
                    do
                        grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                           # A syscall was not found in the candidate rule
                           all_syscalls_found=1
                           }
                    done
                    if [[ $all_syscalls_found -eq 0 ]]
                    then
                        # We found a rule with all the syscall(s) we want; skip rest of macro
                        skip=0
                        break
                    fi

                    # Check if this rule can be grouped with our target syscall and keep track of it
                    for syscall_g in "${syscall_grouping[@]}"
                    do
                        if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                        then
                            file_to_edit=${audit_file}
                            rule_to_edit=${rule}
                            rule_syscalls_to_edit=${rule_syscalls}
                        fi
                    done
                done
            else
                # If there is any candidate rule, it is compliant; skip rest of macro
                if [ "${#candidate_rules[@]}" -gt 0 ]
                then
                    skip=0
                fi
            fi

            if [ "$skip" -eq 0 ]; then
                break
            fi
        done

        if [ "$skip" -ne 0 ]; then
            # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
            # At this point we know if we need to either append the $full_rule or group
            # the syscall together with an exsiting rule

            # Append the full_rule if it cannot be grouped to any other rule
            if [ -z ${rule_to_edit+x} ]
            then
                # Build full_rule while avoid adding double spaces when other_filters is empty
                if [ "${#syscall_a[@]}" -gt 0 ]
                then
                    syscall_string=""
                    for syscall in "${syscall_a[@]}"
                    do
                        syscall_string+=" -S $syscall"
                    done
                fi
                other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
                auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
                full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
                echo "$full_rule" >> "$default_file"
                chmod 0600 ${default_file}
            else
                # Check if the syscalls are declared as a comma separated list or
                # as multiple -S parameters
                if grep -q -- "," <<< "${rule_syscalls_to_edit}"
                then
                    delimiter=","
                else
                    delimiter=" -S "
                fi
                new_grouped_syscalls="${rule_syscalls_to_edit}"
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                       # A syscall was not found in the candidate rule
                       new_grouped_syscalls+="${delimiter}${syscall}"
                       }
                done

                # Group the syscall in the rule
                sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
            fi
        fi
        unset syscall_a
        unset syscall_grouping
        unset syscall_string
        unset syscall
        unset file_to_edit
        unset rule_to_edit
        unset rule_syscalls_to_edit
        unset other_string
        unset auid_string
        unset full_rule

        # Load macro arguments into arrays
        read -a syscall_a <<< $SYSCALL
        read -a syscall_grouping <<< $SYSCALL_GROUPING

        # Create a list of audit *.rules files that should be inspected for presence and correctness
        # of a particular audit rule. The scheme is as follows:
        #
        # -----------------------------------------------------------------------------------------
        #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
        # -----------------------------------------------------------------------------------------
        #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
        # -----------------------------------------------------------------------------------------
        #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
        #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
        # -----------------------------------------------------------------------------------------
        #
        files_to_inspect=()

        # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
        # file to the list of files to be inspected
        default_file="/etc/audit/audit.rules"
        files_to_inspect+=('/etc/audit/audit.rules' )

        # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
        skip=1

        for audit_file in "${files_to_inspect[@]}"
        do
            # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
            # i.e, collect rules that match:
            # * the action, list and arch, (2-nd argument)
            # * the other filters, (3-rd argument)
            # * the auid filters, (4-rd argument)
            readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

            candidate_rules=()
            # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
            for s_rule in "${similar_rules[@]}"
            do
                # Strip all the options and fields we know of,
                # than check if there was any field left over
                extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
                grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
            done

            if [[ ${#syscall_a[@]} -ge 1 ]]
            then
                # Check if the syscall we want is present in any of the similar existing rules
                for rule in "${candidate_rules[@]}"
                do
                    rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                    all_syscalls_found=0
                    for syscall in "${syscall_a[@]}"
                    do
                        grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                           # A syscall was not found in the candidate rule
                           all_syscalls_found=1
                           }
                    done
                    if [[ $all_syscalls_found -eq 0 ]]
                    then
                        # We found a rule with all the syscall(s) we want; skip rest of macro
                        skip=0
                        break
                    fi

                    # Check if this rule can be grouped with our target syscall and keep track of it
                    for syscall_g in "${syscall_grouping[@]}"
                    do
                        if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                        then
                            file_to_edit=${audit_file}
                            rule_to_edit=${rule}
                            rule_syscalls_to_edit=${rule_syscalls}
                        fi
                    done
                done
            else
                # If there is any candidate rule, it is compliant; skip rest of macro
                if [ "${#candidate_rules[@]}" -gt 0 ]
                then
                    skip=0
                fi
            fi

            if [ "$skip" -eq 0 ]; then
                break
            fi
        done

        if [ "$skip" -ne 0 ]; then
            # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
            # At this point we know if we need to either append the $full_rule or group
            # the syscall together with an exsiting rule

            # Append the full_rule if it cannot be grouped to any other rule
            if [ -z ${rule_to_edit+x} ]
            then
                # Build full_rule while avoid adding double spaces when other_filters is empty
                if [ "${#syscall_a[@]}" -gt 0 ]
                then
                    syscall_string=""
                    for syscall in "${syscall_a[@]}"
                    do
                        syscall_string+=" -S $syscall"
                    done
                fi
                other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
                auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
                full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
                echo "$full_rule" >> "$default_file"
                chmod 0600 ${default_file}
            else
                # Check if the syscalls are declared as a comma separated list or
                # as multiple -S parameters
                if grep -q -- "," <<< "${rule_syscalls_to_edit}"
                then
                    delimiter=","
                else
                    delimiter=" -S "
                fi
                new_grouped_syscalls="${rule_syscalls_to_edit}"
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                       # A syscall was not found in the candidate rule
                       new_grouped_syscalls+="${delimiter}${syscall}"
                       }
                done

                # Group the syscall in the rule
                sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
            fi
        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_stime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Perform remediation of Audit rules for stime syscall for x86 platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - stime
          syscall_grouping:
          - adjtimex
          - settimeofday
          - stime

      - name: Check existence of stime in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/audit_time_rules.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_time_rules.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - stime
          syscall_grouping:
          - adjtimex
          - settimeofday
          - stime

      - name: Check existence of stime in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_time_rules
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ( not ( ansible_architecture == "aarch64" ) and not ( ansible_architecture ==
        "s390x" ) )
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_stime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Attempts to Alter the localtime File [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/localtime -p wa -k audit_time_rules
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /etc/localtime -p wa -k audit_time_rules
Rationale: | Arbitrary changes to the system time can be used to obfuscate nefarious activities in log files, as well as to confuse network services that are highly dependent upon an accurate system time (such as sshd). All changes to the system time should be audited.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_time_watch_localtime
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.4.2.b
anssi | R73
cis | 5.2.3.4
ism | 0582
pcidss4 | 10.6.3, 10.6
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/localtime" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/localtime $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/localtime$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/localtime -p wa -k audit_time_rules" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/audit_time_rules.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/localtime" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/audit_time_rules.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/audit_time_rules.rules"
        # If the audit_time_rules.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/localtime" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/localtime $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/localtime$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/localtime -p wa -k audit_time_rules" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_watch_localtime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter the localtime File - Check if watch rule for /etc/localtime
        already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/localtime\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_watch_localtime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter the localtime File - Search /etc/audit/rules.d for
        other rules with specified key audit_time_rules
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)audit_time_rules$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_watch_localtime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter the localtime File - Use /etc/audit/rules.d/audit_time_rules.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/audit_time_rules.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_watch_localtime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter the localtime File - Use matched file as the recipient
        for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_watch_localtime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter the localtime File - Add watch rule for /etc/localtime
        in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/localtime -p wa -k audit_time_rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_watch_localtime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter the localtime File - Check if watch rule for /etc/localtime
        already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/localtime\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_watch_localtime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to Alter the localtime File - Add watch rule for /etc/localtime
        in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/localtime -p wa -k audit_time_rules
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.4.2.b
      - PCI-DSSv4-10.6
      - PCI-DSSv4-10.6.3
      - audit_rules_time_watch_localtime
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Make the auditd Configuration Immutable [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d` in order to make the auditd configuration immutable:
    -e 2
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file in order to make the auditd configuration immutable:
    -e 2
With this setting, a reboot will be required to change any audit rules.
Rationale: | Making the audit configuration immutable prevents accidental as well as malicious modification of the audit rules, although it may be problematic if legitimate changes are needed during system operation.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_immutable
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8
cjis | 5.4.1.1
cobit5 | APO01.06, APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.3.1, 3.4.3
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.310(a)(2)(iv), 164.312(d), 164.310(d)(2)(iii), 164.312(b), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, ID.SC-4, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4
pcidss | Req-10.5.2
os-srg | SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
app-srg-ctr | SRG-APP-000119-CTR-000245, SRG-APP-000120-CTR-000250
anssi | R73
cis | 5.2.3.20
pcidss4 | 10.3.2, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Traverse all of:
    #
    # /etc/audit/audit.rules,			(for auditctl case)
    # /etc/audit/rules.d/*.rules			(for augenrules case)
    #
    # files to check if '-e .*' setting is present in that '*.rules' file already.
    # If found, delete such occurrence since auditctl(8) manual page instructs the
    # '-e 2' rule should be placed as the last rule in the configuration
    find /etc/audit /etc/audit/rules.d -maxdepth 1 -type f -name '*.rules' -exec sed -i '/-e[[:space:]]\+.*/d' {} ';'

    # Append '-e 2' requirement at the end of both:
    # * /etc/audit/audit.rules file 		(for auditctl case)
    # * /etc/audit/rules.d/immutable.rules		(for augenrules case)

    for AUDIT_FILE in "/etc/audit/audit.rules" "/etc/audit/rules.d/immutable.rules"
    do
    	echo '' >> $AUDIT_FILE
    	echo '# Set the audit.rules configuration immutable per security requirements' >> $AUDIT_FILE
    	echo '# Reboot is required to change audit rules once this setting is applied' >> $AUDIT_FILE
    	echo '-e 2' >> $AUDIT_FILE
    	chmod o-rwx $AUDIT_FILE
    	chmod g-rwx $AUDIT_FILE
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-171-3.4.3
      - NIST-800-53-AC-6(9)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - audit_rules_immutable
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Make the auditd Configuration Immutable - Collect all files from /etc/audit/rules.d
        with .rules extension
      ansible.builtin.find:
        paths: /etc/audit/rules.d/
        patterns: '*.rules'
      register: find_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-171-3.4.3
      - NIST-800-53-AC-6(9)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - audit_rules_immutable
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Make the auditd Configuration Immutable - Check if target files exist and
        get their content
      ansible.builtin.stat:
        path: '{{ item }}'
      register: audit_files_stat
      loop:
      - /etc/audit/audit.rules
      - /etc/audit/rules.d/immutable.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-171-3.4.3
      - NIST-800-53-AC-6(9)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - audit_rules_immutable
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Make the auditd Configuration Immutable - Read content of existing audit files
      ansible.builtin.slurp:
        src: '{{ item.item }}'
      register: audit_files_content
      loop: '{{ audit_files_stat.results }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - item.stat.exists
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-171-3.4.3
      - NIST-800-53-AC-6(9)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - audit_rules_immutable
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Make the auditd Configuration Immutable - Check if -e 2 is already correctly
        set in target files
      ansible.builtin.set_fact:
        immutable_correctly_set: |-
          {{
            audit_files_content.results
            | selectattr('content', 'defined')
            | map(attribute='content')
            | map('b64decode')
            | select('search', '^-e 2$', multiline=True)
            | list
            | length == 2
          }}
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-171-3.4.3
      - NIST-800-53-AC-6(9)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - audit_rules_immutable
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Make the auditd Configuration Immutable - Remove any existing -e option from
        all Audit config files
      ansible.builtin.lineinfile:
        path: '{{ item }}'
        regexp: ^\s*-e\s+.*$
        state: absent
      loop: '{{ find_rules_d.files | map(attribute=''path'') | list + [''/etc/audit/audit.rules'']
        }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not immutable_correctly_set
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-171-3.4.3
      - NIST-800-53-AC-6(9)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - audit_rules_immutable
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Make the auditd Configuration Immutable - Ensure target directories exist
      ansible.builtin.file:
        path: '{{ item | dirname }}'
        state: directory
        mode: '0750'
      loop:
      - /etc/audit/audit.rules
      - /etc/audit/rules.d/immutable.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not immutable_correctly_set
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-171-3.4.3
      - NIST-800-53-AC-6(9)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - audit_rules_immutable
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Make the auditd Configuration Immutable - Add Audit -e 2 option to make rules
        immutable
      ansible.builtin.lineinfile:
        path: '{{ item }}'
        create: true
        line: -e 2
        regexp: ^\s*-e\s+.*$
        mode: g-rwx,o-rwx
      loop:
      - /etc/audit/audit.rules
      - /etc/audit/rules.d/immutable.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - not immutable_correctly_set
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-171-3.4.3
      - NIST-800-53-AC-6(9)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.2
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.2
      - audit_rules_immutable
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Mandatory Access Controls [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/selinux/ -p wa -k MAC-policy
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file:
    -w /etc/selinux/ -p wa -k MAC-policy
Rationale: | The system's mandatory access policy (SELinux or Apparmor) should not be arbitrarily changed by anything other than administrator action. All changes to MAC policy should be audited.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_mac_modification
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.8
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
anssi | R73
cis | 5.2.3.14
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/selinux/" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/selinux/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/selinux/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/selinux/ -p wa -k MAC-policy" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/MAC-policy.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/selinux/" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/MAC-policy.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/MAC-policy.rules"
        # If the MAC-policy.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/selinux/" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/selinux/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/selinux/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/selinux/ -p wa -k MAC-policy" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_mac_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls - Check if
        watch rule for /etc/selinux/ already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/selinux/\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_mac_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls - Search
        /etc/audit/rules.d for other rules with specified key MAC-policy
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)MAC-policy$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_mac_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls - Use /etc/audit/rules.d/MAC-policy.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/MAC-policy.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_mac_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls - Use matched
        file as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_mac_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls - Add watch
        rule for /etc/selinux/ in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/selinux/ -p wa -k MAC-policy
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_mac_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls - Check if
        watch rule for /etc/selinux/ already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/selinux/\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_mac_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls - Add watch
        rule for /etc/selinux/ in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/selinux/ -p wa -k MAC-policy
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_mac_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Mandatory Access Controls in usr/share [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /usr/share/selinux/ -p wa -k MAC-policy
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /usr/share/selinux/ -p wa -k MAC-policy
Rationale: | The system's mandatory access policy (SELinux) should not be arbitrarily changed by anything other than administrator action. All changes to MAC policy should be audited.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_mac_modification_usr_share
References: |
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.8
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
cis | 5.2.3.14
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/usr/share/selinux/" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/usr/share/selinux/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/usr/share/selinux/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /usr/share/selinux/ -p wa -k MAC-policy" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/MAC-policy.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/usr/share/selinux/" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/MAC-policy.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/MAC-policy.rules"
        # If the MAC-policy.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/usr/share/selinux/" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/usr/share/selinux/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/usr/share/selinux/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /usr/share/selinux/ -p wa -k MAC-policy" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - audit_rules_mac_modification_usr_share
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls in usr/share
        - Check if watch rule for /usr/share/selinux/ already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/usr/share/selinux/\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - audit_rules_mac_modification_usr_share
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls in usr/share
        - Search /etc/audit/rules.d for other rules with specified key MAC-policy
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)MAC-policy$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - audit_rules_mac_modification_usr_share
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls in usr/share
        - Use /etc/audit/rules.d/MAC-policy.rules as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/MAC-policy.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - audit_rules_mac_modification_usr_share
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls in usr/share
        - Use matched file as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - audit_rules_mac_modification_usr_share
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls in usr/share
        - Add watch rule for /usr/share/selinux/ in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /usr/share/selinux/ -p wa -k MAC-policy
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - audit_rules_mac_modification_usr_share
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls in usr/share
        - Check if watch rule for /usr/share/selinux/ already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/usr/share/selinux/\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - audit_rules_mac_modification_usr_share
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Mandatory Access Controls in usr/share
        - Add watch rule for /usr/share/selinux/ in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /usr/share/selinux/ -p wa -k MAC-policy
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - NIST-800-171-3.1.8
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - audit_rules_mac_modification_usr_share
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Ensure auditd Collects Information on Exporting to Media (successful) [ref]
At a minimum, the audit system should collect media exportation events for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following line to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S mount -F auid>=1000 -F auid!=unset -F key=export
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following line to `/etc/audit/audit.rules` file, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S mount -F auid>=1000 -F auid!=unset -F key=export
Rationale: | The unauthorized exportation of data to external media could result in an information leak where classified information, Privacy Act information, and intellectual property could be lost. An audit trail should be created each time a filesystem is mounted to help identify and guard against information loss.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_media_export
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.7
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
app-srg-ctr | SRG-APP-000495-CTR-001235
anssi | R73
cis | 5.2.3.10
pcidss4 | 10.2.1.7, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS="-F auid>=1000 -F auid!=unset"
    	SYSCALL="mount"
    	KEY="export"
    	SYSCALL_GROUPING=""

    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_media_export
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Set architecture for audit mount tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_media_export
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for mount for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - mount
          syscall_grouping: []

      - name: Check existence of mount in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/export.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/export.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=export
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - mount
          syscall_grouping: []

      - name: Check existence of mount in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=export
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_media_export
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Perform remediation of Audit rules for mount for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - mount
          syscall_grouping: []

      - name: Check existence of mount in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/export.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/export.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k
            |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=export
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - mount
          syscall_grouping: []

      - name: Check existence of mount in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* -F auid>=1000 -F auid!=unset (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( -F auid>=1000 -F auid!=unset (?:-k |-F
            key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F auid>=1000
            -F auid!=unset -F key=export
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.7
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.7
      - audit_rules_media_export
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events that Modify the System's Network Environment [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S sethostname,setdomainname -F key=audit_rules_networkconfig_modification
    -w /etc/issue -p wa -k audit_rules_networkconfig_modification
    -w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
    -w /etc/hosts -p wa -k audit_rules_networkconfig_modification

    -w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file, setting ARCH to either b32 for 32-bit system, or having two lines for both b32 and b64 in case your system is 64-bit:
    -a always,exit -F arch=ARCH -S sethostname,setdomainname -F key=audit_rules_networkconfig_modification
    -w /etc/issue -p wa -k audit_rules_networkconfig_modification
    -w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
    -w /etc/hosts -p wa -k audit_rules_networkconfig_modification
    -w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
Rationale: | The network environment should not be modified by anything other than administrator action. Any change to network parameters should be audited.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_networkconfig_modification
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.5.5
anssi | R73
cis | 5.2.3.5
ism | 0582
pcidss4 | 10.3.4, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # First perform the remediation of the syscall rule
    # Retrieve hardware architecture of the underlying system
    [ "$(getconf LONG_BIT)" = "32" ] && RULE_ARCHS=("b32") || RULE_ARCHS=("b32" "b64")

    for ARCH in "${RULE_ARCHS[@]}"
    do
    	ACTION_ARCH_FILTERS="-a always,exit -F arch=$ARCH"
    	OTHER_FILTERS=""
    	AUID_FILTERS=""
    	SYSCALL="sethostname setdomainname"
    	KEY="audit_rules_networkconfig_modification"
    	SYSCALL_GROUPING="sethostname setdomainname"
    	# Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'augenrules', then check if the audit rule is defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to the list for inspection
    # If rule isn't defined yet, add '/etc/audit/rules.d/$key.rules' to the list for inspection
    default_file="/etc/audit/rules.d/$KEY.rules"
    # As other_filters may include paths, lets use a different delimiter for it
    # The "F" script expression tells sed to print the filenames where the expressions matched
    readarray -t files_to_inspect < <(sed -s -n -e "/^$ACTION_ARCH_FILTERS/!d" -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" -e "F" /etc/audit/rules.d/*.rules)
    # Case when particular rule isn't defined in /etc/audit/rules.d/*.rules yet
    if [ ${#files_to_inspect[@]} -eq "0" ]
    then
        file_to_inspect="/etc/audit/rules.d/$KEY.rules"
        files_to_inspect=("$file_to_inspect")
        if [ ! -e "$file_to_inspect" ]
        then
            touch "$file_to_inspect"
            chmod 0600 "$file_to_inspect"
        fi
    fi

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    	unset syscall_a
    unset syscall_grouping
    unset syscall_string
    unset syscall
    unset file_to_edit
    unset rule_to_edit
    unset rule_syscalls_to_edit
    unset other_string
    unset auid_string
    unset full_rule

    # Load macro arguments into arrays
    read -a syscall_a <<< $SYSCALL
    read -a syscall_grouping <<< $SYSCALL_GROUPING

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    #  Tool used to load audit rules | Rule already defined  |  Audit rules file to inspect    |
    # -----------------------------------------------------------------------------------------
    #        auditctl                |     Doesn't matter    |  /etc/audit/audit.rules         |
    # -----------------------------------------------------------------------------------------
    #        augenrules              |          Yes          |  /etc/audit/rules.d/*.rules     |
    #        augenrules              |          No           |  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    #
    files_to_inspect=()

    # If audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # file to the list of files to be inspected
    default_file="/etc/audit/audit.rules"
    files_to_inspect+=('/etc/audit/audit.rules' )

    # After converting to jinja, we cannot return; therefore we skip the rest of the macro if needed instead
    skip=1

    for audit_file in "${files_to_inspect[@]}"
    do
        # Filter existing $audit_file rules' definitions to select those that satisfy the rule pattern,
        # i.e, collect rules that match:
        # * the action, list and arch, (2-nd argument)
        # * the other filters, (3-rd argument)
        # * the auid filters, (4-rd argument)
        readarray -t similar_rules < <(sed -e "/^$ACTION_ARCH_FILTERS/!d"  -e "\#$OTHER_FILTERS#!d" -e "/$AUID_FILTERS/!d" "$audit_file")

        candidate_rules=()
        # Filter out rules that have more fields then required. This will remove rules more specific than the required scope
        for s_rule in "${similar_rules[@]}"
        do
            # Strip all the options and fields we know of,
            # than check if there was any field left over
            extra_fields=$(sed -E -e "s/^$ACTION_ARCH_FILTERS//"  -e "s#$OTHER_FILTERS##" -e "s/$AUID_FILTERS//" -e "s/((:?-S [[:alnum:],]+)+)//g" -e "s/-F key=\w+|-k \w+//"<<< "$s_rule")
            grep -q -- "-F" <<< "$extra_fields" || candidate_rules+=("$s_rule")
        done

        if [[ ${#syscall_a[@]} -ge 1 ]]
        then
            # Check if the syscall we want is present in any of the similar existing rules
            for rule in "${candidate_rules[@]}"
            do
                rule_syscalls=$(echo "$rule" | grep -o -P '(-S [\w,]+)+' | xargs)
                all_syscalls_found=0
                for syscall in "${syscall_a[@]}"
                do
                    grep -q -- "\b${syscall}\b" <<< "$rule_syscalls" || {
                       # A syscall was not found in the candidate rule
                       all_syscalls_found=1
                       }
                done
                if [[ $all_syscalls_found -eq 0 ]]
                then
                    # We found a rule with all the syscall(s) we want; skip rest of macro
                    skip=0
                    break
                fi

                # Check if this rule can be grouped with our target syscall and keep track of it
                for syscall_g in "${syscall_grouping[@]}"
                do
                    if grep -q -- "\b${syscall_g}\b" <<< "$rule_syscalls"
                    then
                        file_to_edit=${audit_file}
                        rule_to_edit=${rule}
                        rule_syscalls_to_edit=${rule_syscalls}
                    fi
                done
            done
        else
            # If there is any candidate rule, it is compliant; skip rest of macro
            if [ "${#candidate_rules[@]}" -gt 0 ]
            then
                skip=0
            fi
        fi

        if [ "$skip" -eq 0 ]; then
            break
        fi
    done

    if [ "$skip" -ne 0 ]; then
        # We checked all rules that matched the expected resemblance pattern (action, arch & auid)
        # At this point we know if we need to either append the $full_rule or group
        # the syscall together with an exsiting rule

        # Append the full_rule if it cannot be grouped to any other rule
        if [ -z ${rule_to_edit+x} ]
        then
            # Build full_rule while avoid adding double spaces when other_filters is empty
            if [ "${#syscall_a[@]}" -gt 0 ]
            then
                syscall_string=""
                for syscall in "${syscall_a[@]}"
                do
                    syscall_string+=" -S $syscall"
                done
            fi
            other_string=$([[ $OTHER_FILTERS ]] && echo " $OTHER_FILTERS") || /bin/true
            auid_string=$([[ $AUID_FILTERS ]] && echo " $AUID_FILTERS") || /bin/true
            full_rule="$ACTION_ARCH_FILTERS${syscall_string}${other_string}${auid_string} -F key=$KEY" || /bin/true
            echo "$full_rule" >> "$default_file"
            chmod 0600 ${default_file}
        else
            # Check if the syscalls are declared as a comma separated list or
            # as multiple -S parameters
            if grep -q -- "," <<< "${rule_syscalls_to_edit}"
            then
                delimiter=","
            else
                delimiter=" -S "
            fi
            new_grouped_syscalls="${rule_syscalls_to_edit}"
            for syscall in "${syscall_a[@]}"
            do
                grep -q -- "\b${syscall}\b" <<< "${rule_syscalls_to_edit}" || {
                   # A syscall was not found in the candidate rule
                   new_grouped_syscalls+="${delimiter}${syscall}"
                   }
            done

            # Group the syscall in the rule
            sed -i -e "\#${rule_to_edit}#s#${rule_syscalls_to_edit}#${new_grouped_syscalls}#" "$file_to_edit"
        fi
    fi
    done

    # Then perform the remediations for the watch rules
    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/issue" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/issue $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/issue$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/issue -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/issue" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
        # If the audit_rules_networkconfig_modification.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/issue" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/issue $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/issue$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/issue -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/issue.net" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/issue.net $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/issue.net$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/issue.net -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/issue.net" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
        # If the audit_rules_networkconfig_modification.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/issue.net" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/issue.net $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/issue.net$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/issue.net -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/hosts" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/hosts $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/hosts$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/hosts -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/hosts" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
        # If the audit_rules_networkconfig_modification.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/hosts" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/hosts $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/hosts$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/hosts -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"

        fi
    done

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/sysconfig/network" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sysconfig/network $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/sysconfig/network$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sysconfig/network" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/audit_rules_networkconfig_modification.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
        # If the audit_rules_networkconfig_modification.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/sysconfig/network" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sysconfig/network $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/sysconfig/network$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Set architecture for audit tasks
      ansible.builtin.set_fact:
        audit_arch: b64
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - ansible_architecture == "aarch64" or ansible_architecture == "ppc64" or ansible_architecture
        == "ppc64le" or ansible_architecture == "s390x" or ansible_architecture == "x86_64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Remediate audit rules for network configuration for 32bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - sethostname
          - setdomainname
          syscall_grouping:
          - sethostname
          - setdomainname

      - name: Check existence of sethostname, setdomainname in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_rules_networkconfig_modification
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - sethostname
          - setdomainname
          syscall_grouping:
          - sethostname
          - setdomainname

      - name: Check existence of sethostname, setdomainname in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b32(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b32)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b32 -S {{ syscalls | join(',') }} -F key=audit_rules_networkconfig_modification
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Remediate audit rules for network configuration for 64bit platform
      block:

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - sethostname
          - setdomainname
          syscall_grouping:
          - sethostname
          - setdomainname

      - name: Check existence of sethostname, setdomainname in /etc/audit/rules.d/
        ansible.builtin.find:
          paths: /etc/audit/rules.d
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: '*.rules'
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Reset syscalls found per file
        ansible.builtin.set_fact:
          syscalls_per_file: {}
          found_paths_dict: {}

      - name: Declare syscalls found per file
        ansible.builtin.set_fact: syscalls_per_file="{{ syscalls_per_file | combine( {item.files[0].path
          :[item.item] + syscalls_per_file.get(item.files[0].path, []) } ) }}"
        loop: '{{ find_command.results | selectattr(''matched'') | list }}'

      - name: Declare files where syscalls were found
        ansible.builtin.set_fact: found_paths="{{ find_command.results | map(attribute='files')
          | flatten | map(attribute='path') | list }}"

      - name: Count occurrences of syscalls in paths
        ansible.builtin.set_fact: found_paths_dict="{{ found_paths_dict | combine({ item:1+found_paths_dict.get(item,
          0) }) }}"
        loop: '{{ find_command.results | map(attribute=''files'') | flatten | map(attribute=''path'')
          | list }}'

      - name: Get path with most syscalls
        ansible.builtin.set_fact: audit_file="{{ (found_paths_dict | dict2items() | sort(attribute='value')
          | last).key }}"
        when: found_paths | length >= 1

      - name: No file with syscall found, set path to /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/rules.d/audit_rules_networkconfig_modification.rules"
        when: found_paths | length == 0

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_per_file[audit_file]
            | join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_rules_networkconfig_modification
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0

      - name: Declare list of syscalls
        ansible.builtin.set_fact:
          syscalls:
          - sethostname
          - setdomainname
          syscall_grouping:
          - sethostname
          - setdomainname

      - name: Check existence of sethostname, setdomainname in /etc/audit/audit.rules
        ansible.builtin.find:
          paths: /etc/audit
          contains: -a always,exit -F arch=b64(( -S |,)\w+)*(( -S |,){{ item }})+(( -S
            |,)\w+)* (-k\s+|-F\s+key=)\S+\s*$
          patterns: audit.rules
        register: find_command
        loop: '{{ (syscall_grouping + syscalls) | unique }}'

      - name: Set path to /etc/audit/audit.rules
        ansible.builtin.set_fact: audit_file="/etc/audit/audit.rules"

      - name: Declare found syscalls
        ansible.builtin.set_fact: syscalls_found="{{ find_command.results | selectattr('matched')
          | map(attribute='item') | list }}"

      - name: Declare missing syscalls
        ansible.builtin.set_fact: missing_syscalls="{{ syscalls | difference(syscalls_found)
          }}"

      - name: Replace the audit rule in {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          regexp: (-a always,exit -F arch=b64)(?=.*(?:(?:-S |,)(?:{{ syscalls_found |
            join("|") }}))\b)((?:( -S |,)\w+)+)( (?:-k |-F key=)\w+)
          line: \1\2\3{{ missing_syscalls | join("\3") }}\4
          backrefs: true
          state: present
          mode: g-rwx,o-rwx
        when: syscalls_found | length > 0 and missing_syscalls | length > 0

      - name: Add the audit rule to {{ audit_file }}
        ansible.builtin.lineinfile:
          path: '{{ audit_file }}'
          line: -a always,exit -F arch=b64 -S {{ syscalls | join(',') }} -F key=audit_rules_networkconfig_modification
          create: true
          mode: g-rwx,o-rwx
          state: present
        when: syscalls_found | length == 0
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - audit_arch == "b64"
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Check if watch
        rule for /etc/issue already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/issue\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Search /etc/audit/rules.d
        for other rules with specified key audit_rules_networkconfig_modification
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)audit_rules_networkconfig_modification$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Use /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Use matched file
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Add watch rule
        for /etc/issue in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/issue -p wa -k audit_rules_networkconfig_modification
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Check if watch
        rule for /etc/issue already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/issue\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Add watch rule
        for /etc/issue in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/issue -p wa -k audit_rules_networkconfig_modification
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Check if watch
        rule for /etc/issue.net already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/issue.net\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Search /etc/audit/rules.d
        for other rules with specified key audit_rules_networkconfig_modification
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)audit_rules_networkconfig_modification$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Use /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Use matched file
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Add watch rule
        for /etc/issue.net in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Check if watch
        rule for /etc/issue.net already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/issue.net\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Add watch rule
        for /etc/issue.net in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/issue.net -p wa -k audit_rules_networkconfig_modification
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Check if watch
        rule for /etc/hosts already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/hosts\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Search /etc/audit/rules.d
        for other rules with specified key audit_rules_networkconfig_modification
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)audit_rules_networkconfig_modification$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Use /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Use matched file
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Add watch rule
        for /etc/hosts in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/hosts -p wa -k audit_rules_networkconfig_modification
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Check if watch
        rule for /etc/hosts already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/hosts\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Add watch rule
        for /etc/hosts in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/hosts -p wa -k audit_rules_networkconfig_modification
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Check if watch
        rule for /etc/sysconfig/network already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/sysconfig/network\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Search /etc/audit/rules.d
        for other rules with specified key audit_rules_networkconfig_modification
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)audit_rules_networkconfig_modification$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Use /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/audit_rules_networkconfig_modification.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Use matched file
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Add watch rule
        for /etc/sysconfig/network in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Check if watch
        rule for /etc/sysconfig/network already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/sysconfig/network\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - Add watch rule
        for /etc/sysconfig/network in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/sysconfig/network -p wa -k audit_rules_networkconfig_modification
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.4
      - audit_rules_networkconfig_modification
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Events that Modify the System's Network Environment - /etc/sysconfig/network-scripts [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/sysconfig/network-scripts -p wa -k system-locale
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /etc/sysconfig/network-scripts -p wa -k system-locale
Rationale: | The network environment should not be modified by anything other than administrator action. Any change to network parameters should be audited.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_networkconfig_modification_network_scripts
References: |
cis | 5.2.3.5
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/sysconfig/network-scripts" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sysconfig/network-scripts $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/sysconfig/network-scripts$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/sysconfig/network-scripts -p wa -k system-locale" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/system-locale.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sysconfig/network-scripts" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/system-locale.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/system-locale.rules"
        # If the system-locale.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/sysconfig/network-scripts" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sysconfig/network-scripts $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/sysconfig/network-scripts$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/sysconfig/network-scripts -p wa -k system-locale" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - audit_rules_networkconfig_modification_network_scripts
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - /etc/sysconfig/network-scripts
        - Check if watch rule for /etc/sysconfig/network-scripts already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/sysconfig/network-scripts\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - audit_rules_networkconfig_modification_network_scripts
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - /etc/sysconfig/network-scripts
        - Search /etc/audit/rules.d for other rules with specified key system-locale
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)system-locale$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - audit_rules_networkconfig_modification_network_scripts
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - /etc/sysconfig/network-scripts
        - Use /etc/audit/rules.d/system-locale.rules as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/system-locale.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - audit_rules_networkconfig_modification_network_scripts
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - /etc/sysconfig/network-scripts
        - Use matched file as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - audit_rules_networkconfig_modification_network_scripts
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - /etc/sysconfig/network-scripts
        - Add watch rule for /etc/sysconfig/network-scripts in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/sysconfig/network-scripts -p wa -k system-locale
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - audit_rules_networkconfig_modification_network_scripts
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - /etc/sysconfig/network-scripts
        - Check if watch rule for /etc/sysconfig/network-scripts already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/sysconfig/network-scripts\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - audit_rules_networkconfig_modification_network_scripts
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify the System's Network Environment - /etc/sysconfig/network-scripts
        - Add watch rule for /etc/sysconfig/network-scripts in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/sysconfig/network-scripts -p wa -k system-locale
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - audit_rules_networkconfig_modification_network_scripts
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Attempts to Alter Process and Session Initiation Information [ref]
The audit system already collects process information for all users and root. If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d` in order to watch for attempted manual edits of files involved in storing such process information:
    -w /var/run/utmp -p wa -k session
    -w /var/log/btmp -p wa -k session
    -w /var/log/wtmp -p wa -k session
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules` file in order to watch for attempted manual edits of files involved in storing such process information:
    -w /var/run/utmp -p wa -k session
    -w /var/log/btmp -p wa -k session
    -w /var/log/wtmp -p wa -k session
Rationale: | Manual editing of these files may indicate nefarious activity, such as an attacker attempting to remove evidence of an intrusion.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_session_events
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AU-2(d), AU-12(c), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.3
app-srg-ctr | SRG-APP-000505-CTR-001285
cis | 5.2.3.11
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/var/run/utmp" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/run/utmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/var/run/utmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /var/run/utmp -p wa -k session" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/session.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/run/utmp" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/session.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/session.rules"
        # If the session.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/var/run/utmp" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/run/utmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/var/run/utmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /var/run/utmp -p wa -k session" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/var/log/btmp" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/btmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/var/log/btmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /var/log/btmp -p wa -k session" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/session.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/btmp" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/session.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/session.rules"
        # If the session.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/var/log/btmp" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/btmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/var/log/btmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /var/log/btmp -p wa -k session" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/var/log/wtmp" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/wtmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/var/log/wtmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /var/log/wtmp -p wa -k session" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/session.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/wtmp" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/session.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/session.rules"
        # If the session.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/var/log/wtmp" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/wtmp $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/var/log/wtmp$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /var/log/wtmp -p wa -k session" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Check
        if watch rule for /var/run/utmp already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/var/run/utmp\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Search
        /etc/audit/rules.d for other rules with specified key session
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)session$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Use
        /etc/audit/rules.d/session.rules as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/session.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Use
        matched file as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Add
        watch rule for /var/run/utmp in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /var/run/utmp -p wa -k session
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Check
        if watch rule for /var/run/utmp already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/var/run/utmp\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Add
        watch rule for /var/run/utmp in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /var/run/utmp -p wa -k session
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Check
        if watch rule for /var/log/btmp already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/var/log/btmp\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Search
        /etc/audit/rules.d for other rules with specified key session
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)session$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Use
        /etc/audit/rules.d/session.rules as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/session.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Use
        matched file as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Add
        watch rule for /var/log/btmp in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /var/log/btmp -p wa -k session
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Check
        if watch rule for /var/log/btmp already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/var/log/btmp\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Add
        watch rule for /var/log/btmp in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /var/log/btmp -p wa -k session
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Check
        if watch rule for /var/log/wtmp already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/var/log/wtmp\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Search
        /etc/audit/rules.d for other rules with specified key session
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)session$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Use
        /etc/audit/rules.d/session.rules as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/session.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Use
        matched file as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Add
        watch rule for /var/log/wtmp in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /var/log/wtmp -p wa -k session
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Check
        if watch rule for /var/log/wtmp already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/var/log/wtmp\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy

    - name: Record Attempts to Alter Process and Session Initiation Information - Add
        watch rule for /var/log/wtmp in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /var/log/wtmp -p wa -k session
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.3
      - audit_rules_session_events
      - low_complexity
      - low_disruption
      - medium_severity
      - reboot_required
      - restrict_strategy
#### Rule Record Events When Executables Are Run As Another User [ref]
Verify the system generates an audit record when actions are run as another user. sudo provides users with temporary elevated privileges to perform operations, either as the superuser or another user. If audit is using the "auditctl" tool to load the rules, run the following command:
    $ sudo grep execve /etc/audit/audit.rules
If audit is using the "augenrules" tool to load the rules, run the following command:
    $ sudo grep -r execve /etc/audit/rules.d
    -a always,exit -F arch=b32 -S execve -C euid!=uid -F auid!=unset -k user_emulation
    -a always,exit -F arch=b64  S execve -C euid!=uid -F auid!=unset -k user_emulation
If both the "b32" and "b64" audit rules for "SUID" files are not defined, this is a finding. Warning: Note that these rules can be configured in a number of ways while still achieving the desired effect.
Rationale: | Creating an audit log of users with temporary elevated privileges and the operation(s) they performed is essential to reporting. Administrators will want to correlate the events written to the audit trail with the records written to sudo's logfile to verify if unauthorized commands have been executed. Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised information system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider threats and the advanced persistent threat.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_suid_auid_privilege_function
References: |
cis | 5.2.3.2
#### Rule Ensure auditd Collects System Administrator Actions [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/sudoers -p wa -k actions
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /etc/sudoers -p wa -k actions
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/sudoers.d/ -p wa -k actions
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /etc/sudoers.d/ -p wa -k actions
Rationale: | The actions taken by system administrators should be audited to keep a record of what was executed on the system, as well as, for accountability purposes.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_sysadmin_actions
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nist | AC-2(7)(b), AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.2, Req-10.2.5.b
os-srg | SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221
app-srg-ctr | SRG-APP-000026-CTR-000070, SRG-APP-000027-CTR-000075, SRG-APP-000028-CTR-000080, SRG-APP-000291-CTR-000675, SRG-APP-000292-CTR-000680, SRG-APP-000293-CTR-000685, SRG-APP-000294-CTR-000690, SRG-APP-000319-CTR-000745, SRG-APP-000320-CTR-000750, SRG-APP-000509-CTR-001305
anssi | R73
cis | 5.2.3.1
ism | 0582
pcidss4 | 10.2.1.5, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/sudoers$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/sudoers -p wa -k actions" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/actions.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sudoers" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/actions.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/actions.rules"
        # If the actions.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/sudoers$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/sudoers -p wa -k actions" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers.d/" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers.d/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/sudoers.d/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/sudoers.d/ -p wa -k actions" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/actions.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/sudoers.d/" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/actions.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/actions.rules"
        # If the actions.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/sudoers.d/" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/sudoers.d/ $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/sudoers.d/$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/sudoers.d/ -p wa -k actions" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Check if watch rule
        for /etc/sudoers already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/sudoers\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Add watch rule for /etc/sudoers
        in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/sudoers -p wa -k actions
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Check if watch rule
        for /etc/sudoers already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/sudoers\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Search /etc/audit/rules.d
        for other rules with specified key actions
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)actions$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Use /etc/audit/rules.d/actions.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/actions.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Use matched file as
        the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Add watch rule for /etc/sudoers
        in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/sudoers -p wa -k actions
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Check if watch rule
        for /etc/sudoers.d/ already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/sudoers.d/\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Add watch rule for /etc/sudoers.d/
        in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/sudoers.d/ -p wa -k actions
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Check if watch rule
        for /etc/sudoers.d/ already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/sudoers.d/\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Search /etc/audit/rules.d
        for other rules with specified key actions
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)actions$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Use /etc/audit/rules.d/actions.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/actions.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Use matched file as
        the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Ensure auditd Collects System Administrator Actions - Add watch rule for /etc/sudoers.d/
        in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/sudoers.d/ -p wa -k actions
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(7)(b)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_sysadmin_actions
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Events that Modify User/Group Information - /etc/group [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/group -p wa -k audit_rules_usergroup_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /etc/group -p wa -k audit_rules_usergroup_modification
Rationale: | In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_usergroup_modification_group
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nerc-cip | CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3
nist | AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.5
os-srg | SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000503-CTR-001275
anssi | R73
cis | 5.2.3.8
ism | 0582
pcidss4 | 10.2.1.5, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/group" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/group $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/group$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/group -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/group" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
        # If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/group" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/group $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/group$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/group -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/group - Check if watch
        rule for /etc/group already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/group\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/group - Search /etc/audit/rules.d
        for other rules with specified key audit_rules_usergroup_modification
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/group - Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/audit_rules_usergroup_modification.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/group - Use matched
        file as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/group - Add watch
        rule for /etc/group in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/group -p wa -k audit_rules_usergroup_modification
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/group - Check if watch
        rule for /etc/group already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/group\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/group - Add watch
        rule for /etc/group in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/group -p wa -k audit_rules_usergroup_modification
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_group
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Events that Modify User/Group Information - /etc/gshadow [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
Rationale: | In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_usergroup_modification_gshadow
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nerc-cip | CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3
nist | AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.5
os-srg | SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000503-CTR-001275
anssi | R73
cis | 5.2.3.8
ism | 0582
pcidss4 | 10.2.1.5, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/gshadow" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/gshadow $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/gshadow$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/gshadow -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/gshadow" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
        # If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/gshadow" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/gshadow $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/gshadow$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/gshadow -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/gshadow - Check if
        watch rule for /etc/gshadow already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/gshadow\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/gshadow - Search /etc/audit/rules.d
        for other rules with specified key audit_rules_usergroup_modification
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/gshadow - Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/audit_rules_usergroup_modification.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/gshadow - Use matched
        file as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/gshadow - Add watch
        rule for /etc/gshadow in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/gshadow - Check if
        watch rule for /etc/gshadow already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/gshadow\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/gshadow - Add watch
        rule for /etc/gshadow in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/gshadow -p wa -k audit_rules_usergroup_modification
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_gshadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Events that Modify User/Group Information - /etc/security/opasswd [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
Rationale: | In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_usergroup_modification_opasswd
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nerc-cip | CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3
nist | AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.5
os-srg | SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000496-CTR-001240, SRG-APP-000497-CTR-001245, SRG-APP-000498-CTR-001250, SRG-APP-000503-CTR-001275
anssi | R73
cis | 5.2.3.8
ism | 0582
pcidss4 | 10.2.1.5, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/security/opasswd" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/security/opasswd $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/security/opasswd$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/security/opasswd" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
        # If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/security/opasswd" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/security/opasswd $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/security/opasswd$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_opasswd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/security/opasswd -
        Check if watch rule for /etc/security/opasswd already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/security/opasswd\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_opasswd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/security/opasswd -
        Search /etc/audit/rules.d for other rules with specified key audit_rules_usergroup_modification
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_opasswd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/security/opasswd -
        Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules as the recipient
        for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/audit_rules_usergroup_modification.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_opasswd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/security/opasswd -
        Use matched file as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_opasswd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/security/opasswd -
        Add watch rule for /etc/security/opasswd in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_opasswd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/security/opasswd -
        Check if watch rule for /etc/security/opasswd already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/security/opasswd\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_opasswd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/security/opasswd -
        Add watch rule for /etc/security/opasswd in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/security/opasswd -p wa -k audit_rules_usergroup_modification
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_opasswd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Events that Modify User/Group Information - /etc/passwd [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/passwd -p wa -k audit_rules_usergroup_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /etc/passwd -p wa -k audit_rules_usergroup_modification
Rationale: | In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_usergroup_modification_passwd
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nerc-cip | CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3
nist | AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.5
os-srg | SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221, SRG-OS-000274-GPOS-00104, SRG-OS-000275-GPOS-00105, SRG-OS-000276-GPOS-00106, SRG-OS-000277-GPOS-00107
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000503-CTR-001275
anssi | R73
cis | 5.2.3.8
ism | 0582
pcidss4 | 10.2.1.5, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/passwd" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/passwd $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/passwd$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/passwd -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/passwd" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
        # If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/passwd" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/passwd $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/passwd$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/passwd -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/passwd - Check if
        watch rule for /etc/passwd already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/passwd\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/passwd - Search /etc/audit/rules.d
        for other rules with specified key audit_rules_usergroup_modification
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/passwd - Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/audit_rules_usergroup_modification.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/passwd - Use matched
        file as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/passwd - Add watch
        rule for /etc/passwd in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/passwd -p wa -k audit_rules_usergroup_modification
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/passwd - Check if
        watch rule for /etc/passwd already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/passwd\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/passwd - Add watch
        rule for /etc/passwd in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/passwd -p wa -k audit_rules_usergroup_modification
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_passwd
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Events that Modify User/Group Information - /etc/shadow [ref]
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /etc/shadow -p wa -k audit_rules_usergroup_modification
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /etc/shadow -p wa -k audit_rules_usergroup_modification
Rationale: | In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_rules_usergroup_modification_shadow
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, DSS06.03, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.1.7
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(3)(ii)(A), 164.308(a)(5)(ii)(C), 164.312(a)(2)(i), 164.312(b), 164.312(d), 164.312(e)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.2.2, 4.3.3.3.9, 4.3.3.5.1, 4.3.3.5.2, 4.3.3.5.8, 4.3.3.6.6, 4.3.3.7.2, 4.3.3.7.3, 4.3.3.7.4, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.1, SR 1.13, SR 1.2, SR 1.3, SR 1.4, SR 1.5, SR 1.7, SR 1.8, SR 1.9, SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.6.2.1, A.6.2.2, A.7.1.1, A.9.1.2, A.9.2.1, A.9.2.2, A.9.2.3, A.9.2.4, A.9.2.6, A.9.3.1, A.9.4.1, A.9.4.2, A.9.4.3, A.9.4.4, A.9.4.5
nerc-cip | CIP-004-6 R2.2.2, CIP-004-6 R2.2.3, CIP-007-3 R.1.3, CIP-007-3 R5, CIP-007-3 R5.1.1, CIP-007-3 R5.1.3, CIP-007-3 R5.2.1, CIP-007-3 R5.2.3
nist | AC-2(4), AU-2(d), AU-12(c), AC-6(9), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-1, PR.AC-3, PR.AC-4, PR.AC-6, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
pcidss | Req-10.2.5
os-srg | SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000466-GPOS-00210, SRG-OS-000476-GPOS-00221
app-srg-ctr | SRG-APP-000495-CTR-001235, SRG-APP-000499-CTR-001255, SRG-APP-000503-CTR-001275
anssi | R73
cis | 5.2.3.8
ism | 0582
pcidss4 | 10.2.1.5, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/shadow" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/shadow $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/shadow$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/shadow -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/etc/shadow" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/audit_rules_usergroup_modification.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/audit_rules_usergroup_modification.rules"
        # If the audit_rules_usergroup_modification.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/etc/shadow" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/etc/shadow $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/etc/shadow$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /etc/shadow -p wa -k audit_rules_usergroup_modification" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/shadow - Check if
        watch rule for /etc/shadow already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/etc/shadow\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/shadow - Search /etc/audit/rules.d
        for other rules with specified key audit_rules_usergroup_modification
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)audit_rules_usergroup_modification$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/shadow - Use /etc/audit/rules.d/audit_rules_usergroup_modification.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/audit_rules_usergroup_modification.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/shadow - Use matched
        file as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/shadow - Add watch
        rule for /etc/shadow in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /etc/shadow -p wa -k audit_rules_usergroup_modification
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/shadow - Check if
        watch rule for /etc/shadow already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/etc/shadow\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Events that Modify User/Group Information - /etc/shadow - Add watch
        rule for /etc/shadow in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /etc/shadow -p wa -k audit_rules_usergroup_modification
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.1.7
      - NIST-800-53-AC-2(4)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.2.5
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.5
      - audit_rules_usergroup_modification_shadow
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Record Attempts to perform maintenance activities [ref]
The Amazon Linux 2023 operating system must generate audit records for privileged activities, nonlocal maintenance, diagnostic sessions and other system-level access. Verify the operating system audits activities performed during nonlocal maintenance and diagnostic sessions. Run the following command:
    $ sudo auditctl -l | grep sudo.log
    -w /var/log/sudo.log -p wa -k maintenance
If the `auditd` daemon is configured to use the `augenrules` program to read audit rules during daemon startup (the default), add the following lines to a file with suffix `.rules` in the directory `/etc/audit/rules.d`:
    -w /var/log/sudo.log -p wa -k maintenance
If the `auditd` daemon is configured to use the `auditctl` utility to read audit rules during daemon startup, add the following lines to `/etc/audit/audit.rules`:
    -w /var/log/sudo.log -p wa -k maintenance
Rationale: | If events associated with nonlocal administrative access or diagnostic sessions are not logged, a major tool for assessing and investigating attacks would not be available. This requirement addresses auditing-related issues associated with maintenance tools used specifically for diagnostic and repair actions on organizational information systems. Nonlocal maintenance and diagnostic activities are those activities conducted by individuals communicating through a network, either an external network (e.g., the internet) or an internal network. Local maintenance and diagnostic activities are those activities carried out by individuals physically present at the information system or information system component and not communicating across a network connection. This requirement applies to hardware/software diagnostic test equipment or tools. This requirement does not cover hardware/software components that may support information system maintenance, yet are a part of the system, for example, the software implementing "ping," "ls," "ipconfig," or the hardware and software implementing the monitoring port of an Ethernet switch.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_audit_sudo_log_events
References: |
pcidss | Req-10.2.2, Req-10.2.5.b
os-srg | SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215
anssi | R73
cis | 5.2.3.3
pcidss4 | 10.2.1.3, 10.2.1, 10.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    # Perform the remediation for both possible tools: 'auditctl' and 'augenrules'

    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit tool is 'auditctl', then add '/etc/audit/audit.rules'
    # into the list of files to be inspected
    files_to_inspect+=('/etc/audit/audit.rules')

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/var/log/sudo.log" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/sudo.log $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/var/log/sudo.log$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /var/log/sudo.log -p wa -k maintenance" >> "$audit_rules_file"

        fi
    done
    # Create a list of audit *.rules files that should be inspected for presence and correctness
    # of a particular audit rule. The scheme is as follows:
    #
    # -----------------------------------------------------------------------------------------
    # Tool used to load audit rules	| Rule already defined	|  Audit rules file to inspect	  |
    # -----------------------------------------------------------------------------------------
    #	auditctl		|     Doesn't matter	|  /etc/audit/audit.rules	  |
    # -----------------------------------------------------------------------------------------
    # 	augenrules		|          Yes		|  /etc/audit/rules.d/*.rules	  |
    # 	augenrules		|          No		|  /etc/audit/rules.d/$key.rules  |
    # -----------------------------------------------------------------------------------------
    files_to_inspect=()

    # If the audit is 'augenrules', then check if rule is already defined
    # If rule is defined, add '/etc/audit/rules.d/*.rules' to list of files for inspection.
    # If rule isn't defined, add '/etc/audit/rules.d/maintenance.rules' to list of files for inspection.

    readarray -t matches < <(grep -HP "[\s]*-w[\s]+/var/log/sudo.log" /etc/audit/rules.d/*.rules)

    # For each of the matched entries
    for match in "${matches[@]}"
    do
        # Extract filepath from the match
        rulesd_audit_file=$(echo $match | cut -f1 -d ':')
        # Append that path into list of files for inspection
        files_to_inspect+=("$rulesd_audit_file")
    done
    # Case when particular audit rule isn't defined yet
    if [ "${#files_to_inspect[@]}" -eq "0" ]
    then
        # Append '/etc/audit/rules.d/maintenance.rules' into list of files for inspection
        key_rule_file="/etc/audit/rules.d/maintenance.rules"
        # If the maintenance.rules file doesn't exist yet, create it with correct permissions
        if [ ! -e "$key_rule_file" ]
        then
            touch "$key_rule_file"
            chmod 0600 "$key_rule_file"
        fi
        files_to_inspect+=("$key_rule_file")
    fi

    # Finally perform the inspection and possible subsequent audit rule
    # correction for each of the files previously identified for inspection
    for audit_rules_file in "${files_to_inspect[@]}"
    do
        # Check if audit watch file system object rule for given path already present

        if grep -q -P -- "^[\s]*-w[\s]+/var/log/sudo.log" "$audit_rules_file"

        then
            # Rule is found => verify yet if existing rule definition contains
            # all of the required access type bits

            # Define BRE whitespace class shortcut
            sp="[[:space:]]"
            # Extract current permission access types (e.g. -p [r|w|x|a] values) from audit rule

            current_access_bits=$(sed -ne "s#$sp*-w$sp\+/var/log/sudo.log $sp\+-p$sp\+\([rxwa]\{1,4\}\).*#\1#p" "$audit_rules_file")

            # Split required access bits string into characters array
            # (to check bit's presence for one bit at a time)
            for access_bit in $(echo "wa" | grep -o .)
            do
                # For each from the required access bits (e.g. 'w', 'a') check
                # if they are already present in current access bits for rule.
                # If not, append that bit at the end
                if ! grep -q "$access_bit" <<< "$current_access_bits"
                then
                    # Concatenate the existing mask with the missing bit
                    current_access_bits="$current_access_bits$access_bit"
                fi
            done
            # Propagate the updated rule's access bits (original + the required
            # ones) back into the /etc/audit/audit.rules file for that rule

            sed -i "s#\($sp*-w$sp\+/var/log/sudo.log$sp\+-p$sp\+\)\([rxwa]\{1,4\}\)\(.*\)#\1$current_access_bits\3#" "$audit_rules_file"

        else
            # Rule isn't present yet. Append it at the end of $audit_rules_file file
            # with proper key

            echo "-w /var/log/sudo.log -p wa -k maintenance" >> "$audit_rules_file"

        fi
    done

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_sudo_log_events
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to perform maintenance activities - Check if watch rule for
        /var/log/sudo.log already exists in /etc/audit/rules.d/
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^\s*-w\s+/var/log/sudo.log\s+-p\s+wa(\s|$)+
        patterns: '*.rules'
      register: find_existing_watch_rules_d
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_sudo_log_events
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to perform maintenance activities - Search /etc/audit/rules.d
        for other rules with specified key maintenance
      ansible.builtin.find:
        paths: /etc/audit/rules.d
        contains: ^.*(?:-F key=|-k\s+)maintenance$
        patterns: '*.rules'
      register: find_watch_key
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_sudo_log_events
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to perform maintenance activities - Use /etc/audit/rules.d/maintenance.rules
        as the recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - /etc/audit/rules.d/maintenance.rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched == 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_sudo_log_events
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to perform maintenance activities - Use matched file as the
        recipient for the rule
      ansible.builtin.set_fact:
        all_files:
        - '{{ find_watch_key.files | map(attribute=''path'') | list | first }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_watch_key.matched is defined and find_watch_key.matched > 0 and find_existing_watch_rules_d.matched
        is defined and find_existing_watch_rules_d.matched == 0
      tags:
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_sudo_log_events
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to perform maintenance activities - Add watch rule for /var/log/sudo.log
        in /etc/audit/rules.d/
      ansible.builtin.lineinfile:
        path: '{{ all_files[0] }}'
        line: -w /var/log/sudo.log -p wa -k maintenance
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_rules_d.matched is defined and find_existing_watch_rules_d.matched
        == 0
      tags:
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_sudo_log_events
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to perform maintenance activities - Check if watch rule for
        /var/log/sudo.log already exists in /etc/audit/audit.rules
      ansible.builtin.find:
        paths: /etc/audit/
        contains: ^\s*-w\s+/var/log/sudo.log\s+-p\s+wa(\s|$)+
        patterns: audit.rules
      register: find_existing_watch_audit_rules
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_sudo_log_events
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: Record Attempts to perform maintenance activities - Add watch rule for /var/log/sudo.log
        in /etc/audit/audit.rules
      ansible.builtin.lineinfile:
        line: -w /var/log/sudo.log -p wa -k maintenance
        state: present
        dest: /etc/audit/audit.rules
        create: true
        mode: '0600'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      - find_existing_watch_audit_rules.matched is defined and find_existing_watch_audit_rules.matched
        == 0
      tags:
      - PCI-DSS-Req-10.2.2
      - PCI-DSS-Req-10.2.5.b
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - PCI-DSSv4-10.2.1.3
      - audit_sudo_log_events
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule System Audit Logs Must Have Mode 0750 or Less Permissive [ref]
Verify the audit log directories have a mode of "0750" or less permissive by first determining where the audit logs are stored with the following command:
    $ sudo grep -iw log_file /etc/audit/auditd.conf
    log_file = /var/log/audit/audit.log
By default, the audit log directory is `/var/log/audit`. Configure the audit log directory to be protected from unauthorized read access by setting the correct permissive mode. The appropriate directory permissions depend on the `log_group` setting in `/etc/audit/auditd.conf`: If `log_group` is set to `root` or is not set, the directory should have mode `0700`. This restricts access to root only, which is the most secure configuration. If `log_group` is set to a group other than `root`, the directory should have mode `0750`. This is necessary because when `log_group` is set to a non-root group, the audit log files are typically configured with mode `0640` (allowing group read access). For group members to access these files, they need execute permission on the directory to traverse it. The `0750` mode allows root full access and the specified group read and execute access, while preventing others from accessing the directory. If `log_group` is set to a group other than `root`, change the mode of the audit log directory with the following command:
    $ sudo chmod 0750 audit_log_directory
Otherwise, change the mode of the audit log directory with the following command:
    $ sudo chmod 0700 audit_log_directory
Replace `audit_log_directory` with the correct audit log directory path.
Rationale: | If users can write to audit logs, audit trails can be modified or destroyed.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_directory_permissions_var_log_audit
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8
cobit5 | APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01
isa-62443-2009 | 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.2, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-004-6 R3.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2, CIP-007-3 R6.5
nist | CM-6(a), AC-6(1), AU-9
nist-csf | DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4
os-srg | SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029
cis | 5.2.4.4
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    if LC_ALL=C grep -iw ^log_file /etc/audit/auditd.conf; then
      DIR=$(awk -F "=" '/^log_file/ {print $2}' /etc/audit/auditd.conf | tr -d ' ' | rev | cut -d"/" -f2- | rev)
    else
      DIR="/var/log/audit"
    fi

    if LC_ALL=C grep -m 1 -q ^log_group /etc/audit/auditd.conf; then
      GROUP=$(awk -F "=" '/log_group/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
      if ! [ "$GROUP" == 'root' ] ; then
        chmod 0750 "$DIR"
      else
        chmod 0700 "$DIR"
      fi
    else
      chmod 0700 "$DIR"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9
      - NIST-800-53-CM-6(a)
      - directory_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: System Audit Logs Must Have Mode 0750 or Less Permissive - Get audit log file
        from /etc/audit/auditd.conf
      ansible.builtin.command: grep -iw ^log_file /etc/audit/auditd.conf
      check_mode: false
      failed_when: false
      changed_when: false
      register: log_file_exists
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9
      - NIST-800-53-CM-6(a)
      - directory_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: System Audit Logs Must Have Mode 0750 or Less Permissive - Set audit log directory
        path
      ansible.builtin.set_fact:
        log_file_dir: '{{ (log_file_exists.stdout | default('''') | split('' '') | last
          | dirname) | default(''/var/log/audit'', true) }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9
      - NIST-800-53-CM-6(a)
      - directory_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: System Audit Logs Must Have Mode 0750 or Less Permissive - Get audit log group
        from /etc/audit/auditd.conf
      ansible.builtin.command: grep -iw ^log_group /etc/audit/auditd.conf
      check_mode: false
      failed_when: false
      changed_when: false
      register: log_group_exists
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9
      - NIST-800-53-CM-6(a)
      - directory_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: System Audit Logs Must Have Mode 0750 or Less Permissive - Set audit log group
      ansible.builtin.set_fact:
        log_group: '{{ (log_group_exists.stdout | default('''') | split('' '') | last)
          | default(''root'', true) }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9
      - NIST-800-53-CM-6(a)
      - directory_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: System Audit Logs Must Have Mode 0750 or Less Permissive - Set audit log directory
        permissions
      ansible.builtin.file:
        path: '{{ log_file_dir }}'
        state: directory
        mode: '{{ ''0700'' if log_group == ''root'' else ''0750'' }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9
      - NIST-800-53-CM-6(a)
      - directory_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule System Audit Logs Must Be Group Owned By Root [ref]
All audit logs must be group owned by root user. The path for audit log can be configured via `log_file` parameter in
    /etc/audit/auditd.conf
or, by default, the path for audit log is
    /var/log/audit/
. To properly set the group owner of `/var/log/audit/*`, run the command:
    $ sudo chgrp root /var/log/audit/*
If `log_group` in `/etc/audit/auditd.conf` is set to a group other than the `root` group account, change the group ownership of the audit logs to this specific group.
Rationale: | Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_group_ownership_var_log_audit
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8
cjis | 5.4.1.1
cobit5 | APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01
cui | 3.3.1
isa-62443-2009 | 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1), AU-9(4)
nist-csf | DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4
pcidss | Req-10.5.1
os-srg | SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084
cis | 5.2.4.3
pcidss4 | 10.3.2, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    if LC_ALL=C grep -iw log_file /etc/audit/auditd.conf; then
      FILE=$(awk -F "=" '/^log_file/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
    else
      FILE="/var/log/audit/audit.log"
    fi

    if LC_ALL=C grep -m 1 -q ^log_group /etc/audit/auditd.conf; then
      GROUP=$(awk -F "=" '/log_group/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
        if ! [ "${GROUP}" == 'root' ]; then
          chgrp ${GROUP} $FILE*
        else
          chgrp root $FILE*
        fi
    else
      chgrp root $FILE*
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
#### Rule Audit Configuration Files Must Be Owned By Group root [ref]
All audit configuration files must be owned by group root.
    chown :root /etc/audit/audit*.{rules,conf} /etc/audit/rules.d/*
Rationale: | Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupownership_audit_configuration
References: |
os-srg | SRG-OS-000063-GPOS-00032
cis | 5.2.4.7
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    find -P /etc/audit/ -maxdepth 1 -type f  ! -group 0 -regextype posix-extended -regex '^.*audit(\.rules|d\.conf)$' -exec chgrp --no-dereference "$newgroup" {} \;
    find -P /etc/audit/rules.d/ -maxdepth 1 -type f  ! -group 0 -regextype posix-extended -regex '^.*\.rules$' -exec chgrp --no-dereference "$newgroup" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - file_groupownership_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupownership_audit_configuration_newgroup variable if represented
        by gid
      ansible.builtin.set_fact:
        file_groupownership_audit_configuration_newgroup: '0'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/audit/ file(s) matching ^.*audit(\.rules|d\.conf)$
      ansible.builtin.command: find -P /etc/audit/ -maxdepth 1 -type f  ! -group 0 -regextype
        posix-extended -regex "^.*audit(\.rules|d\.conf)$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/audit/ file(s) matching ^.*audit(\.rules|d\.conf)$
      ansible.builtin.file:
        path: '{{ item }}'
        follow: false
        group: '{{ file_groupownership_audit_configuration_newgroup }}'
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/audit/rules.d/ file(s) matching ^.*\.rules$
      ansible.builtin.command: find -P /etc/audit/rules.d/ -maxdepth 1 -type f  ! -group
        0 -regextype posix-extended -regex "^.*\.rules$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /etc/audit/rules.d/ file(s) matching ^.*\.rules$
      ansible.builtin.file:
        path: '{{ item }}'
        follow: false
        group: '{{ file_groupownership_audit_configuration_newgroup }}'
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Audit Configuration Files Must Be Owned By Root [ref]
All audit configuration files must be owned by root user. To properly set the owner of `/etc/audit/`, run the command:
    $ sudo chown root /etc/audit/
To properly set the owner of `/etc/audit/rules.d/`, run the command:
    $ sudo chown root /etc/audit/rules.d/
Rationale: | Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_ownership_audit_configuration
References: |
os-srg | SRG-OS-000063-GPOS-00032
cis | 5.2.4.6
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else

    find -P /etc/audit/ -maxdepth 1 -type f  ! -user 0 -regextype posix-extended -regex '^.*audit(\.rules|d\.conf)$' -exec chown --no-dereference "$newown" {} \;

    find -P /etc/audit/rules.d/ -maxdepth 1 -type f  ! -user 0 -regextype posix-extended -regex '^.*\.rules$' -exec chown --no-dereference "$newown" {} \;

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - file_ownership_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_ownership_audit_configuration_newown variable if represented
        by uid
      ansible.builtin.set_fact:
        file_ownership_audit_configuration_newown: '0'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/audit/ file(s) matching ^.*audit(\.rules|d\.conf)$
      ansible.builtin.command: find -P /etc/audit/ -maxdepth 1 -type f  ! -user 0 -regextype
        posix-extended -regex "^.*audit(\.rules|d\.conf)$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/audit/ file(s) matching ^.*audit(\.rules|d\.conf)$
      ansible.builtin.file:
        path: '{{ item }}'
        follow: false
        owner: '{{ file_ownership_audit_configuration_newown }}'
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/audit/rules.d/ file(s) matching ^.*\.rules$
      ansible.builtin.command: find -P /etc/audit/rules.d/ -maxdepth 1 -type f  ! -user
        0 -regextype posix-extended -regex "^.*\.rules$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /etc/audit/rules.d/ file(s) matching ^.*\.rules$
      ansible.builtin.file:
        path: '{{ item }}'
        follow: false
        owner: '{{ file_ownership_audit_configuration_newown }}'
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule System Audit Logs Must Be Owned By Root [ref]
All audit logs must be owned by root user. The path for audit log can be configured via `log_file` parameter in
    /etc/audit/auditd.conf
or by default, the path for audit log is
    /var/log/audit/
. To properly set the owner of `/var/log/audit/*`, run the command:
    $ sudo chown root /var/log/audit/*
Rationale: | Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_ownership_var_log_audit_stig
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8
cjis | 5.4.1.1
cobit5 | APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01
cui | 3.3.1
isa-62443-2009 | 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nist | CM-6(a), AC-6(1), AU-9(4)
nist-csf | DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4
pcidss | Req-10.5.1
os-srg | SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084
cis | 5.2.4.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    if LC_ALL=C grep -iw log_file /etc/audit/auditd.conf; then
        FILE=$(awk -F "=" '/^log_file/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
        chown root $FILE*
    else
        chown root /var/log/audit/audit.log*
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
#### Rule Audit Configuration Files Permissions are 640 or More Restrictive [ref]
All audit configuration files permissions must be 640 or more restrictive.
    chmod 0640 /etc/audit/audit*.{rules,conf} /etc/audit/rules.d/*
Rationale: | Without the capability to restrict which roles and individuals can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_audit_configuration
References: |
nist | AU-12 b
os-srg | SRG-OS-000063-GPOS-00032
cis | 5.2.4.5
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    find -P /etc/audit/ -maxdepth 1 -perm /u+xs,g+xws,o+xwrt  -type f -regextype posix-extended -regex '^.*audit(\.rules|d\.conf)$' -exec chmod u-xs,g-xws,o-xwrt {} \;

    find -P /etc/audit/rules.d/ -maxdepth 1 -perm /u+xs,g+xws,o+xwrt  -type f -regextype posix-extended -regex '^.*\.rules$' -exec chmod u-xs,g-xws,o-xwrt {} \;

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AU-12 b
      - configure_strategy
      - file_permissions_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/audit/ file(s)
      ansible.builtin.command: find -P /etc/audit/ -maxdepth 1 -perm /u+xs,g+xws,o+xwrt  -type
        f -regextype posix-extended -regex "^.*audit(\.rules|d\.conf)$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AU-12 b
      - configure_strategy
      - file_permissions_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for /etc/audit/ file(s)
      ansible.builtin.file:
        path: '{{ item }}'
        mode: u-xs,g-xws,o-xwrt
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AU-12 b
      - configure_strategy
      - file_permissions_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Find /etc/audit/rules.d/ file(s)
      ansible.builtin.command: find -P /etc/audit/rules.d/ -maxdepth 1 -perm /u+xs,g+xws,o+xwrt  -type
        f -regextype posix-extended -regex "^.*\.rules$"
      register: files_found
      changed_when: false
      failed_when: false
      check_mode: false
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AU-12 b
      - configure_strategy
      - file_permissions_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set permissions for /etc/audit/rules.d/ file(s)
      ansible.builtin.file:
        path: '{{ item }}'
        mode: u-xs,g-xws,o-xwrt
        state: file
      with_items:
      - '{{ files_found.stdout_lines }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AU-12 b
      - configure_strategy
      - file_permissions_audit_configuration
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule System Audit Logs Must Have Mode 0640 or Less Permissive [ref]
Verify the audit log files have a mode of "0640" or less permissive by first determining where the audit logs are stored with the following command:
    $ sudo grep -iw log_file /etc/audit/auditd.conf
    log_file = /var/log/audit/audit.log
By default, the audit log file is `/var/log/audit/audit.log`. Configure the audit log to be protected from unauthorized read access by setting the correct permissive mode. If `log_group` in `/etc/audit/auditd.conf` is set to a group other than the `root` group account, change the mode of the audit log files with the following command:
    $ sudo chmod 0640 audit_log_file
Otherwise, change the mode of the audit log files with the following command:
    $ sudo chmod 0600 audit_log_file
Replace `audit_log_file` with the correct audit log file path.
Rationale: | If users can write to audit logs, audit trails can be modified or destroyed.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_var_log_audit
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 18, 19, 3, 4, 5, 6, 7, 8
cjis | 5.4.1.1
cobit5 | APO01.06, APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, DSS06.02, MEA02.01
cui | 3.3.1
isa-62443-2009 | 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.7.3, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.1, SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 5.2, SR 6.1
iso27001-2013 | A.10.1.1, A.11.1.4, A.11.1.5, A.11.2.1, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.1.3, A.13.2.1, A.13.2.3, A.13.2.4, A.14.1.2, A.14.1.3, A.16.1.4, A.16.1.5, A.16.1.7, A.6.1.2, A.7.1.1, A.7.1.2, A.7.3.1, A.8.2.2, A.8.2.3, A.9.1.1, A.9.1.2, A.9.2.3, A.9.4.1, A.9.4.4, A.9.4.5
nerc-cip | CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.3, CIP-007-3 R2.1, CIP-007-3 R2.2, CIP-007-3 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.1, CIP-007-3 R5.1.2
nist | CM-6(a), AC-6(1), AU-9(4)
nist-csf | DE.AE-3, DE.AE-5, PR.AC-4, PR.DS-5, PR.PT-1, RS.AN-1, RS.AN-4
pcidss | Req-10.5
os-srg | SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084
app-srg-ctr | SRG-APP-000118-CTR-000240
cis | 5.2.4.1
pcidss4 | 10.3.1, 10.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    if LC_ALL=C grep -iw ^log_file /etc/audit/auditd.conf; then
        FILE=$(awk -F "=" '/^log_file/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
    else
        FILE="/var/log/audit/audit.log"
    fi

    if LC_ALL=C grep -m 1 -q ^log_group /etc/audit/auditd.conf; then
        GROUP=$(awk -F "=" '/log_group/ {print $2}' /etc/audit/auditd.conf | tr -d ' ')
        if ! [ "$GROUP" == 'root' ] ; then
           chmod 0640 "$FILE"
        else
           chmod 0600 "$FILE"
        fi
    else
        chmod 0600 "$FILE"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9(4)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - file_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: System Audit Logs Must Have Mode 0640 or Less Permissive - Get audit log file
        from /etc/audit/auditd.conf
      ansible.builtin.command: grep -iw ^log_file /etc/audit/auditd.conf
      check_mode: false
      failed_when: false
      changed_when: false
      register: log_file_exists
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9(4)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - file_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: System Audit Logs Must Have Mode 0640 or Less Permissive - Set audit log file
        path
      ansible.builtin.set_fact:
        log_file_path: '{{ (log_file_exists.stdout | default('''') | split('' '') | last)
          | default(''/var/log/audit/audit.log'', true) }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9(4)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - file_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: System Audit Logs Must Have Mode 0640 or Less Permissive - Get audit log group
        from /etc/audit/auditd.conf
      ansible.builtin.command: grep -iw ^log_group /etc/audit/auditd.conf
      check_mode: false
      failed_when: false
      changed_when: false
      register: log_group_exists
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9(4)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - file_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: System Audit Logs Must Have Mode 0640 or Less Permissive - Set audit log group
      ansible.builtin.set_fact:
        log_group: '{{ (log_group_exists.stdout | default('''') | split('' '') | last)
          | default(''root'', true) }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9(4)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - file_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy

    - name: System Audit Logs Must Have Mode 0640 or Less Permissive - Set audit log file
        permissions
      ansible.builtin.file:
        path: '{{ log_file_path }}'
        state: file
        mode: '{{ ''0600'' if log_group == ''root'' else ''0640'' }}'
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-6(1)
      - NIST-800-53-AU-9(4)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.5
      - PCI-DSSv4-10.3
      - PCI-DSSv4-10.3.1
      - file_permissions_var_log_audit
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
Group Configure auditd Data Retention Group contains 5 rules
[ref] The audit system writes data to `/var/log/audit/audit.log`. By default, `auditd` rotates 5 logs by size (6MB), retaining a maximum of 30MB of data in total, and refuses to write entries when the disk is too full. This minimizes the risk of audit data filling its partition and impacting other services. This also minimizes the risk of the audit daemon temporarily disabling the system if it cannot write audit log (which it can be configured to do). For a busy system or a system which is thoroughly auditing system activity, the default settings for data retention may be insufficient. The log file size needed will depend heavily on what types of events are being audited. First configure auditing to log all the events of interest. Then monitor the log size manually for awhile to determine what file size will allow you to keep the required data for the correct time period. Using a dedicated partition for `/var/log/audit` prevents the `auditd` logs from disrupting system functionality if they fill, and, more importantly, prevents other activity in `/var` from filling the partition and stopping the audit trail. (The audit logs are size-limited and therefore unlikely to grow without bound unless configured to do so.) Some machines may have requirements that no actions occur which cannot be audited. If this is the case, then `auditd` can be configured to halt the machine if it runs out of space. Note: Since older logs are rotated, configuring `auditd` this way does not prevent older logs from being rotated away before they can be viewed. If your system is configured to halt when logging cannot be performed, make sure this can never happen under normal circumstances! Ensure that `/var/log/audit` is on its own partition, and that this partition is larger than the maximum amount of data `auditd` will retain normally.
#### Rule Configure auditd mail_acct Action on Low Disk Space [ref]
The `auditd` service can be configured to send email to a designated account in certain situations. Add or correct the following line in `/etc/audit/auditd.conf` to ensure that administrators are notified via email for those situations:
    action_mail_acct = root
Rationale: | Email sent to the root account is typically aliased to the administrators of the system, who can take appropriate action.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_auditd_data_retention_action_mail_acct
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8
cjis | 5.4.1.1
cobit5 | APO11.04, APO12.06, APO13.01, BAI03.05, BAI04.04, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, MEA02.01
cui | 3.3.1
hipaa | 164.312(a)(2)(ii)
isa-62443-2009 | 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 7.1, SR 7.2
iso27001-2013 | A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.16.1.4, A.16.1.5, A.16.1.7, A.17.2.1
nerc-cip | CIP-003-8 R1.3, CIP-003-8 R3, CIP-003-8 R3.1, CIP-003-8 R3.2, CIP-003-8 R3.3, CIP-003-8 R5.1.1, CIP-003-8 R5.3, CIP-004-6 R2.2.3, CIP-004-6 R2.3, CIP-007-3 R5.1, CIP-007-3 R5.1.2, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3
nist | IA-5(1), AU-5(a), AU-5(2), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, PR.DS-4, PR.PT-1, RS.AN-1, RS.AN-4
pcidss | Req-10.7.a
os-srg | SRG-OS-000046-GPOS-00022, SRG-OS-000343-GPOS-00134
cis | 5.2.2.3
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    var_auditd_action_mail_acct='root'

    AUDITCONFIG=/etc/audit/auditd.conf

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^action_mail_acct")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_action_mail_acct"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^action_mail_acct\\>" "$AUDITCONFIG"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^action_mail_acct\\>.*/$escaped_formatted_output/gi" "$AUDITCONFIG"
    else
        if [[ -s "$AUDITCONFIG" ]] && [[ -n "$(tail -c 1 -- "$AUDITCONFIG" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "$AUDITCONFIG"
        fi
        printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AU-5(2)
      - NIST-800-53-AU-5(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)
      - PCI-DSS-Req-10.7.a
      - auditd_data_retention_action_mail_acct
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_auditd_action_mail_acct # promote to variable
      set_fact:
        var_auditd_action_mail_acct: !!str root
      tags:
        - always

    - name: Configure auditd mail_acct Action on Low Disk Space - Configure auditd mail_acct
        Action on Low Disk Space
      ansible.builtin.lineinfile:
        dest: /etc/audit/auditd.conf
        regexp: ^action_mail_acct
        line: action_mail_acct = {{ var_auditd_action_mail_acct }}
        state: present
        create: true
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AU-5(2)
      - NIST-800-53-AU-5(a)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IA-5(1)
      - PCI-DSS-Req-10.7.a
      - auditd_data_retention_action_mail_acct
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Configure auditd admin_space_left Action on Low Disk Space [ref]
The `auditd` service can be configured to take an action when disk space is running low but prior to running out of space completely. Edit the file `/etc/audit/auditd.conf`. Add or modify the following line, substituting ACTION appropriately:
    admin_space_left_action = ACTION
Set this value to `single` to cause the system to switch to single user mode for corrective action. Acceptable values also include `suspend` and `halt`. For certain systems, the need for availability outweighs the need to log all actions, and a different setting should be determined. Details regarding all possible values for ACTION are described in the `auditd.conf` man page.
Rationale: | Administrators should be made aware of an inability to record audit records. If a separate partition or logical volume of adequate size is used, running low on space for audit records should never occur.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_auditd_data_retention_admin_space_left_action
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8
cjis | 5.4.1.1
cobit5 | APO11.04, APO12.06, APO13.01, BAI03.05, BAI04.04, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, MEA02.01
cui | 3.3.1
hipaa | 164.312(a)(2)(ii)
isa-62443-2009 | 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 7.1, SR 7.2
iso27001-2013 | A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.16.1.4, A.16.1.5, A.16.1.7, A.17.2.1
nist | AU-5(b), AU-5(2), AU-5(1), AU-5(4), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, PR.DS-4, PR.PT-1, RS.AN-1, RS.AN-4
pcidss | Req-10.7
os-srg | SRG-OS-000343-GPOS-00134
cis | 5.2.2.3
pcidss4 | 10.5.1, 10.5
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    var_auditd_admin_space_left_action='halt'

    var_auditd_admin_space_left_action="$(echo $var_auditd_admin_space_left_action | cut -d \| -f 1)"

    AUDITCONFIG=/etc/audit/auditd.conf

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^admin_space_left_action")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_admin_space_left_action"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^admin_space_left_action\\>" "$AUDITCONFIG"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^admin_space_left_action\\>.*/$escaped_formatted_output/gi" "$AUDITCONFIG"
    else
        if [[ -s "$AUDITCONFIG" ]] && [[ -n "$(tail -c 1 -- "$AUDITCONFIG" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "$AUDITCONFIG"
        fi
        printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AU-5(1)
      - NIST-800-53-AU-5(2)
      - NIST-800-53-AU-5(4)
      - NIST-800-53-AU-5(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.7
      - PCI-DSSv4-10.5
      - PCI-DSSv4-10.5.1
      - auditd_data_retention_admin_space_left_action
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_auditd_admin_space_left_action # promote to variable
      set_fact:
        var_auditd_admin_space_left_action: !!str halt
      tags:
        - always

    - name: Configure auditd admin_space_left Action on Low Disk Space
      ansible.builtin.lineinfile:
        dest: /etc/audit/auditd.conf
        line: admin_space_left_action = {{ var_auditd_admin_space_left_action .split('|')[0]
          }}
        regexp: ^\s*admin_space_left_action\s*=\s*.*$
        state: present
        create: true
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AU-5(1)
      - NIST-800-53-AU-5(2)
      - NIST-800-53-AU-5(4)
      - NIST-800-53-AU-5(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.7
      - PCI-DSSv4-10.5
      - PCI-DSSv4-10.5.1
      - auditd_data_retention_admin_space_left_action
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Configure auditd Max Log File Size [ref]
Determine the amount of audit data (in megabytes) which should be retained in each log file. Edit the file `/etc/audit/auditd.conf`. Add or modify the following line, substituting the correct value of 6 for STOREMB:
    max_log_file = STOREMB
Set the value to `6` (MB) or higher for general-purpose systems. Larger values, of course, support retention of even more audit data.
Rationale: | The total storage for audit log files must be large enough to retain log information over the period required. This is a function of the maximum log file size and the number of logs retained.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_auditd_data_retention_max_log_file
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 3, 4, 5, 6, 7, 8
cjis | 5.4.1.1
cobit5 | APO11.04, APO12.06, BAI03.05, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, MEA02.01
isa-62443-2009 | 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1
iso27001-2013 | A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.16.1.4, A.16.1.5, A.16.1.7
nerc-cip | CIP-004-6 R2.2.3, CIP-004-6 R3.3, CIP-007-3 R5.2, CIP-007-3 R5.3.1, CIP-007-3 R5.3.2, CIP-007-3 R5.3.3, CIP-007-3 R6.5
nist | AU-11, CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, PR.PT-1, RS.AN-1, RS.AN-4
pcidss | Req-10.7
cis | 5.2.2.1
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    var_auditd_max_log_file='6'

    AUDITCONFIG=/etc/audit/auditd.conf

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^max_log_file")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_max_log_file"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^max_log_file\\>" "$AUDITCONFIG"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^max_log_file\\>.*/$escaped_formatted_output/gi" "$AUDITCONFIG"
    else
        if [[ -s "$AUDITCONFIG" ]] && [[ -n "$(tail -c 1 -- "$AUDITCONFIG" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "$AUDITCONFIG"
        fi
        printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-53-AU-11
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.7
      - auditd_data_retention_max_log_file
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_auditd_max_log_file # promote to variable
      set_fact:
        var_auditd_max_log_file: !!str 6
      tags:
        - always

    - name: Configure auditd Max Log File Size
      ansible.builtin.lineinfile:
        dest: /etc/audit/auditd.conf
        regexp: ^\s*max_log_file\s*=\s*.*$
        line: max_log_file = {{ var_auditd_max_log_file }}
        state: present
        create: true
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-53-AU-11
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.7
      - auditd_data_retention_max_log_file
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Configure auditd max_log_file_action Upon Reaching Maximum Log Size [ref]
The default action to take when the logs reach their maximum size is to rotate the log files, discarding the oldest one. To configure the action taken by `auditd`, add or correct the line in `/etc/audit/auditd.conf`:
    max_log_file_action = ACTION
Possible values for ACTION are described in the `auditd.conf` man page. These include: `ignore` `syslog` `suspend` `rotate` `keep_logs` Set the `ACTION` to `keep_logs`. The setting is case-insensitive.
Rationale: | Automatically rotating logs (by setting this to `rotate`) minimizes the chances of the system unexpectedly running out of disk space by being overwhelmed with log data. However, for systems that must never discard log data, or which use external processes to transfer it and reclaim space, `keep_logs` can be employed.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_auditd_data_retention_max_log_file_action
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8
cjis | 5.4.1.1
cobit5 | APO11.04, APO12.06, APO13.01, BAI03.05, BAI04.04, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, MEA02.01
hipaa | 164.312(a)(2)(ii)
isa-62443-2009 | 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 7.1, SR 7.2
iso27001-2013 | A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.16.1.4, A.16.1.5, A.16.1.7, A.17.2.1
nist | AU-5(b), AU-5(2), AU-5(1), AU-5(4), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, PR.DS-4, PR.PT-1, RS.AN-1, RS.AN-4
pcidss | Req-10.7
os-srg | SRG-OS-000047-GPOS-00023
cis | 5.2.2.2
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    var_auditd_max_log_file_action='keep_logs'

    AUDITCONFIG=/etc/audit/auditd.conf

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^max_log_file_action")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_max_log_file_action"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^max_log_file_action\\>" "$AUDITCONFIG"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^max_log_file_action\\>.*/$escaped_formatted_output/gi" "$AUDITCONFIG"
    else
        if [[ -s "$AUDITCONFIG" ]] && [[ -n "$(tail -c 1 -- "$AUDITCONFIG" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "$AUDITCONFIG"
        fi
        printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-53-AU-5(1)
      - NIST-800-53-AU-5(2)
      - NIST-800-53-AU-5(4)
      - NIST-800-53-AU-5(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.7
      - auditd_data_retention_max_log_file_action
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_auditd_max_log_file_action # promote to variable
      set_fact:
        var_auditd_max_log_file_action: !!str keep_logs
      tags:
        - always

    - name: Configure auditd max_log_file_action Upon Reaching Maximum Log Size
      ansible.builtin.lineinfile:
        dest: /etc/audit/auditd.conf
        line: max_log_file_action = {{ var_auditd_max_log_file_action }}
        regexp: ^\s*max_log_file_action\s*=\s*.*$
        state: present
        create: true
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-53-AU-5(1)
      - NIST-800-53-AU-5(2)
      - NIST-800-53-AU-5(4)
      - NIST-800-53-AU-5(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.7
      - auditd_data_retention_max_log_file_action
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
#### Rule Configure auditd space_left Action on Low Disk Space [ref]
The `auditd` service can be configured to take an action when disk space starts to run low. Edit the file `/etc/audit/auditd.conf`. Modify the following line, substituting ACTION appropriately:
    space_left_action = ACTION
Possible values for ACTION are described in the `auditd.conf` man page. These include: `syslog` `email` `exec` `suspend` `single` `halt` Set this to `email` (instead of the default, which is `suspend`) as it is more likely to get prompt attention. Acceptable values also include `suspend`, `single`, and `halt`.
Rationale: | Notifying administrators of an impending disk space problem may allow them to take corrective action prior to any disruption.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_auditd_data_retention_space_left_action
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8
cjis | 5.4.1.1
cobit5 | APO11.04, APO12.06, APO13.01, BAI03.05, BAI04.04, BAI08.02, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.04, DSS05.07, MEA02.01
cui | 3.3.1
hipaa | 164.312(a)(2)(ii)
isa-62443-2009 | 4.2.3.10, 4.3.3.3.9, 4.3.3.5.8, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 2.10, SR 2.11, SR 2.12, SR 2.8, SR 2.9, SR 6.1, SR 7.1, SR 7.2
iso27001-2013 | A.12.1.3, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.16.1.4, A.16.1.5, A.16.1.7, A.17.2.1
nist | AU-5(b), AU-5(2), AU-5(1), AU-5(4), CM-6(a)
nist-csf | DE.AE-3, DE.AE-5, PR.DS-4, PR.PT-1, RS.AN-1, RS.AN-4
pcidss | Req-10.7
os-srg | SRG-OS-000343-GPOS-00134
cis | 5.2.2.3
pcidss4 | 10.5.1, 10.5
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q audit && rpm --quiet -q kernel; then

    var_auditd_space_left_action='email'

    var_auditd_space_left_action="$(echo $var_auditd_space_left_action | cut -d \| -f 1)"
    #
    # If space_left_action present in /etc/audit/auditd.conf, change value
    # to var_auditd_space_left_action, else
    # add "space_left_action = $var_auditd_space_left_action" to /etc/audit/auditd.conf
    #

    AUDITCONFIG=/etc/audit/auditd.conf

    # Strip any search characters in the key arg so that the key can be replaced without
    # adding any search characters to the config file.
    stripped_key=$(sed 's/[\^=\$,;+]*//g' <<< "^space_left_action")

    # shellcheck disable=SC2059
    printf -v formatted_output "%s = %s" "$stripped_key" "$var_auditd_space_left_action"

    # If the key exists, change it. Otherwise, add it to the config_file.
    # We search for the key string followed by a word boundary (matched by \>),
    # so if we search for 'setting', 'setting2' won't match.
    if LC_ALL=C grep -q -m 1 -i -e "^space_left_action\\>" "$AUDITCONFIG"; then
        escaped_formatted_output=$(sed -e 's|/|\\/|g' <<< "$formatted_output")
        LC_ALL=C sed -i --follow-symlinks "s/^space_left_action\\>.*/$escaped_formatted_output/gi" "$AUDITCONFIG"
    else
        if [[ -s "$AUDITCONFIG" ]] && [[ -n "$(tail -c 1 -- "$AUDITCONFIG" || true)" ]]; then
            LC_ALL=C sed -i --follow-symlinks '$a'\\ "$AUDITCONFIG"
        fi
        printf '%s\n' "$formatted_output" >> "$AUDITCONFIG"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AU-5(1)
      - NIST-800-53-AU-5(2)
      - NIST-800-53-AU-5(4)
      - NIST-800-53-AU-5(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.7
      - PCI-DSSv4-10.5
      - PCI-DSSv4-10.5.1
      - auditd_data_retention_space_left_action
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
    - name: XCCDF Value var_auditd_space_left_action # promote to variable
      set_fact:
        var_auditd_space_left_action: !!str email
      tags:
        - always

    - name: Configure auditd space_left Action on Low Disk Space
      ansible.builtin.lineinfile:
        dest: /etc/audit/auditd.conf
        line: space_left_action = {{ var_auditd_space_left_action.split('|')[0] }}
        regexp: ^\s*space_left_action\s*=\s*.*$
        state: present
        create: true
      when:
      - '"audit" in ansible_facts.packages'
      - '"kernel" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AU-5(1)
      - NIST-800-53-AU-5(2)
      - NIST-800-53-AU-5(4)
      - NIST-800-53-AU-5(b)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.7
      - PCI-DSSv4-10.5
      - PCI-DSSv4-10.5.1
      - auditd_data_retention_space_left_action
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - restrict_strategy
Group System Accounting with auditd Group contains 3 rules
[ref] The audit service provides substantial capabilities for recording system activities. This section deals with permissions of auditd related files.
#### Rule Verify that audit tools are owned by group root [ref]
The Amazon Linux 2023 operating system audit tools must have the proper ownership configured to protected against unauthorized access. Verify it by running the following command:
    $ stat -c "%n %G" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/audispd /sbin/augenrules

    /sbin/auditctl root

    /sbin/aureport root

    /sbin/ausearch root

    /sbin/autrace root

    /sbin/auditd root

    /sbin/audispd root

    /sbin/augenrules root
Audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators
Rationale: | Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Operating systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys to make access decisions regarding the access to audit tools.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_groupownership_audit_binaries
References: |
os-srg | SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098
cis | 5.2.4.10
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newgroup=""
    if getent group "0" >/dev/null 2>&1; then
      newgroup="0"
    fi

    if [[ -z "${newgroup}" ]]; then
      >&2 echo "0 is not a defined group on the system"
    else
    if ! stat -c "%g %G" "/sbin/auditctl" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /sbin/auditctl
    fi
    if ! stat -c "%g %G" "/sbin/aureport" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /sbin/aureport
    fi
    if ! stat -c "%g %G" "/sbin/ausearch" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /sbin/ausearch
    fi
    if ! stat -c "%g %G" "/sbin/autrace" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /sbin/autrace
    fi
    if ! stat -c "%g %G" "/sbin/auditd" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /sbin/auditd
    fi
    if ! stat -c "%g %G" "/sbin/audispd" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /sbin/audispd
    fi
    if ! stat -c "%g %G" "/sbin/augenrules" | grep -E -w -q "0"; then
        chgrp --no-dereference "$newgroup" /sbin/augenrules
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_groupownership_audit_binaries_newgroup variable if represented
        by gid
      ansible.builtin.set_fact:
        file_groupownership_audit_binaries_newgroup: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/auditctl
      ansible.builtin.stat:
        path: /sbin/auditctl
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /sbin/auditctl
      ansible.builtin.file:
        path: /sbin/auditctl
        follow: false
        group: '{{ file_groupownership_audit_binaries_newgroup }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/aureport
      ansible.builtin.stat:
        path: /sbin/aureport
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /sbin/aureport
      ansible.builtin.file:
        path: /sbin/aureport
        follow: false
        group: '{{ file_groupownership_audit_binaries_newgroup }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/ausearch
      ansible.builtin.stat:
        path: /sbin/ausearch
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /sbin/ausearch
      ansible.builtin.file:
        path: /sbin/ausearch
        follow: false
        group: '{{ file_groupownership_audit_binaries_newgroup }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/autrace
      ansible.builtin.stat:
        path: /sbin/autrace
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /sbin/autrace
      ansible.builtin.file:
        path: /sbin/autrace
        follow: false
        group: '{{ file_groupownership_audit_binaries_newgroup }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/auditd
      ansible.builtin.stat:
        path: /sbin/auditd
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /sbin/auditd
      ansible.builtin.file:
        path: /sbin/auditd
        follow: false
        group: '{{ file_groupownership_audit_binaries_newgroup }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/audispd
      ansible.builtin.stat:
        path: /sbin/audispd
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /sbin/audispd
      ansible.builtin.file:
        path: /sbin/audispd
        follow: false
        group: '{{ file_groupownership_audit_binaries_newgroup }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/augenrules
      ansible.builtin.stat:
        path: /sbin/augenrules
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure group owner on /sbin/augenrules
      ansible.builtin.file:
        path: /sbin/augenrules
        follow: false
        group: '{{ file_groupownership_audit_binaries_newgroup }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_groupownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify that audit tools are owned by root [ref]
The Amazon Linux 2023 operating system audit tools must have the proper ownership configured to protected against unauthorized access. Verify it by running the following command:
    $ stat -c "%n %U" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/audispd /sbin/augenrules

    /sbin/auditctl root

    /sbin/aureport root

    /sbin/ausearch root

    /sbin/autrace root

    /sbin/auditd root

    /sbin/audispd root

    /sbin/augenrules root
Audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators
Rationale: | Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Operating systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys to make access decisions regarding the access to audit tools.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_ownership_audit_binaries
References: |
os-srg | SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098
cis | 5.2.4.9
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    newown=""
    if id "0" >/dev/null 2>&1; then
      newown="0"
    fi

    if [[ -z "$newown" ]]; then
      >&2 echo "0 is not a defined user on the system"
    else
    if ! stat -c "%u %U" "/sbin/auditctl" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /sbin/auditctl
    fi
    if ! stat -c "%u %U" "/sbin/aureport" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /sbin/aureport
    fi
    if ! stat -c "%u %U" "/sbin/ausearch" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /sbin/ausearch
    fi
    if ! stat -c "%u %U" "/sbin/autrace" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /sbin/autrace
    fi
    if ! stat -c "%u %U" "/sbin/auditd" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /sbin/auditd
    fi
    if ! stat -c "%u %U" "/sbin/audispd" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /sbin/audispd
    fi
    if ! stat -c "%u %U" "/sbin/augenrules" | grep -E -w -q "0"; then
        chown --no-dereference "$newown" /sbin/augenrules
    fi

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Set the file_ownership_audit_binaries_newown variable if represented by uid
      ansible.builtin.set_fact:
        file_ownership_audit_binaries_newown: '0'
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/auditctl
      ansible.builtin.stat:
        path: /sbin/auditctl
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /sbin/auditctl
      ansible.builtin.file:
        path: /sbin/auditctl
        follow: false
        owner: '{{ file_ownership_audit_binaries_newown }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/aureport
      ansible.builtin.stat:
        path: /sbin/aureport
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /sbin/aureport
      ansible.builtin.file:
        path: /sbin/aureport
        follow: false
        owner: '{{ file_ownership_audit_binaries_newown }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/ausearch
      ansible.builtin.stat:
        path: /sbin/ausearch
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /sbin/ausearch
      ansible.builtin.file:
        path: /sbin/ausearch
        follow: false
        owner: '{{ file_ownership_audit_binaries_newown }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/autrace
      ansible.builtin.stat:
        path: /sbin/autrace
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /sbin/autrace
      ansible.builtin.file:
        path: /sbin/autrace
        follow: false
        owner: '{{ file_ownership_audit_binaries_newown }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/auditd
      ansible.builtin.stat:
        path: /sbin/auditd
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /sbin/auditd
      ansible.builtin.file:
        path: /sbin/auditd
        follow: false
        owner: '{{ file_ownership_audit_binaries_newown }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/audispd
      ansible.builtin.stat:
        path: /sbin/audispd
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /sbin/audispd
      ansible.builtin.file:
        path: /sbin/audispd
        follow: false
        owner: '{{ file_ownership_audit_binaries_newown }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/augenrules
      ansible.builtin.stat:
        path: /sbin/augenrules
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure owner on /sbin/augenrules
      ansible.builtin.file:
        path: /sbin/augenrules
        follow: false
        owner: '{{ file_ownership_audit_binaries_newown }}'
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_ownership_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Verify that audit tools Have Mode 0755 or less [ref]
The Amazon Linux 2023 operating system audit tools must have the proper permissions configured to protected against unauthorized access. Verify it by running the following command:
    $ stat -c "%n %a" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/audispd /sbin/augenrules

    /sbin/auditctl 755

    /sbin/aureport 755

    /sbin/ausearch 755

    /sbin/autrace 755

    /sbin/auditd 755

    /sbin/audispd 755

    /sbin/augenrules 755
Audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators
Rationale: | Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. Operating systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools and the corresponding rights the user enjoys to make access decisions regarding the access to audit tools.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_file_permissions_audit_binaries
References: |
os-srg | SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098
cis | 5.2.4.8
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    chmod u-s,g-ws,o-wt /sbin/auditctl

    chmod u-s,g-ws,o-wt /sbin/aureport

    chmod u-s,g-ws,o-wt /sbin/ausearch

    chmod u-s,g-ws,o-wt /sbin/autrace

    chmod u-s,g-ws,o-wt /sbin/auditd

    chmod u-s,g-ws,o-wt /sbin/audispd

    chmod u-s,g-ws,o-wt /sbin/augenrules

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | configure
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/auditctl
      ansible.builtin.stat:
        path: /sbin/auditctl
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-s,g-ws,o-wt on /sbin/auditctl
      ansible.builtin.file:
        path: /sbin/auditctl
        mode: u-s,g-ws,o-wt
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/aureport
      ansible.builtin.stat:
        path: /sbin/aureport
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-s,g-ws,o-wt on /sbin/aureport
      ansible.builtin.file:
        path: /sbin/aureport
        mode: u-s,g-ws,o-wt
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/ausearch
      ansible.builtin.stat:
        path: /sbin/ausearch
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-s,g-ws,o-wt on /sbin/ausearch
      ansible.builtin.file:
        path: /sbin/ausearch
        mode: u-s,g-ws,o-wt
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/autrace
      ansible.builtin.stat:
        path: /sbin/autrace
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-s,g-ws,o-wt on /sbin/autrace
      ansible.builtin.file:
        path: /sbin/autrace
        mode: u-s,g-ws,o-wt
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/auditd
      ansible.builtin.stat:
        path: /sbin/auditd
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-s,g-ws,o-wt on /sbin/auditd
      ansible.builtin.file:
        path: /sbin/auditd
        mode: u-s,g-ws,o-wt
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/audispd
      ansible.builtin.stat:
        path: /sbin/audispd
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-s,g-ws,o-wt on /sbin/audispd
      ansible.builtin.file:
        path: /sbin/audispd
        mode: u-s,g-ws,o-wt
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Test for existence /sbin/augenrules
      ansible.builtin.stat:
        path: /sbin/augenrules
      register: file_exists
      when: '"kernel" in ansible_facts.packages'
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed

    - name: Ensure permission u-s,g-ws,o-wt on /sbin/augenrules
      ansible.builtin.file:
        path: /sbin/augenrules
        mode: u-s,g-ws,o-wt
      when:
      - '"kernel" in ansible_facts.packages'
      - file_exists.stat is defined and file_exists.stat.exists
      tags:
      - configure_strategy
      - file_permissions_audit_binaries
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
#### Rule Ensure the audit Subsystem is Installed [ref]
The audit package should be installed.
Rationale: | The auditd service is an access monitoring and accounting daemon, watching system calls to audit any access, in comparison with potential local access control policy such as SELinux policy.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_package_audit_installed
References: |
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b)
nerc-cip | CIP-004-6 R3.3, CIP-007-3 R6.5
nist | AC-7(a), AU-7(1), AU-7(2), AU-14, AU-12(2), AU-2(a), CM-6(a)
ospp | FAU_GEN.1
pcidss | Req-10.1
os-srg | SRG-OS-000062-GPOS-00031, SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000054-GPOS-00025, SRG-OS-000122-GPOS-00063, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096, SRG-OS-000337-GPOS-00129, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000475-GPOS-00220
anssi | R33, R73
cis | 5.2.1.1
ism | 0582, 0846
pcidss4 | 10.2.1, 10.2
Remediation OSBuild Blueprint snippet ⇲
    [[packages]]
    name = "audit"
    version = "*"
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel; then

    if ! rpm -q --quiet "audit" ; then
        dnf install -y "audit"
    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Anaconda snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    package --add=audit
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-AC-7(a)
      - NIST-800-53-AU-12(2)
      - NIST-800-53-AU-14
      - NIST-800-53-AU-2(a)
      - NIST-800-53-AU-7(1)
      - NIST-800-53-AU-7(2)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.1
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_audit_installed

    - name: Ensure audit is installed
      ansible.builtin.package:
        name: audit
        state: present
      when: '"kernel" in ansible_facts.packages'
      tags:
      - NIST-800-53-AC-7(a)
      - NIST-800-53-AU-12(2)
      - NIST-800-53-AU-14
      - NIST-800-53-AU-2(a)
      - NIST-800-53-AU-7(1)
      - NIST-800-53-AU-7(2)
      - NIST-800-53-CM-6(a)
      - PCI-DSS-Req-10.1
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - package_audit_installed
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include install_audit

    class install_audit {
      package { 'audit':
        ensure => 'installed',
      }
    }
#### Rule Enable auditd Service [ref]
The `auditd` service is an essential userspace component of the Linux Auditing System, as it is responsible for writing audit records to disk. The `auditd` service can be enabled with the following command:
    $ sudo systemctl enable auditd.service
Rationale: | Without establishing what type of events occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Ensuring the `auditd` service is active ensures audit records generated by the kernel are appropriately recorded. Additionally, a properly configured audit subsystem ensures that actions of individual system users can be uniquely traced to those users so they can be held accountable for their actions.
Severity: | medium
Rule ID: | xccdf_org.ssgproject.content_rule_service_auditd_enabled
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 2, 3, 4, 5, 6, 7, 8, 9
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.03, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS03.05, DSS05.02, DSS05.03, DSS05.04, DSS05.05, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.3.1, 3.3.2, 3.3.6
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 6.2, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.14.2.7, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nerc-cip | CIP-004-6 R3.3, CIP-007-3 R6.5
nist | AC-2(g), AU-3, AU-10, AU-2(d), AU-12(c), AU-14(1), AC-6(9), CM-6(a), SI-4(23)
nist-csf | DE.AE-3, DE.AE-5, DE.CM-1, DE.CM-3, DE.CM-7, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
ospp | FAU_GEN.1
pcidss | Req-10.1
os-srg | SRG-OS-000062-GPOS-00031, SRG-OS-000037-GPOS-00015, SRG-OS-000038-GPOS-00016, SRG-OS-000039-GPOS-00017, SRG-OS-000040-GPOS-00018, SRG-OS-000041-GPOS-00019, SRG-OS-000042-GPOS-00021, SRG-OS-000051-GPOS-00024, SRG-OS-000054-GPOS-00025, SRG-OS-000122-GPOS-00063, SRG-OS-000254-GPOS-00095, SRG-OS-000255-GPOS-00096, SRG-OS-000337-GPOS-00129, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000475-GPOS-00220
app-srg-ctr | SRG-APP-000095-CTR-000170, SRG-APP-000409-CTR-000990, SRG-APP-000508-CTR-001300, SRG-APP-000510-CTR-001310
anssi | R33, R73
cis | 5.2.1.4
ism | 1409
pcidss4 | 10.2.1, 10.2
Remediation Kubernetes snippet ⇲
    ---
    apiVersion: machineconfiguration.openshift.io/v1
    kind: MachineConfig
    spec:
      config:
        ignition:
          version: 3.1.0
        systemd:
          units:
          - name: auditd.service
            enabled: true
Remediation OSBuild Blueprint snippet ⇲
    [customizations.services]
    enabled = ["auditd"]
Remediation Shell script ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q audit; }; then

    SYSTEMCTL_EXEC='/usr/bin/systemctl'
    "$SYSTEMCTL_EXEC" unmask 'auditd.service'
    if [[ $("$SYSTEMCTL_EXEC" is-system-running) != "offline" ]]; then
      "$SYSTEMCTL_EXEC" start 'auditd.service'
    fi
    "$SYSTEMCTL_EXEC" enable 'auditd.service'

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-171-3.3.2
      - NIST-800-171-3.3.6
      - NIST-800-53-AC-2(g)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-10
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-14(1)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-AU-3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SI-4(23)
      - PCI-DSS-Req-10.1
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_auditd_enabled

    - name: Enable auditd Service - Enable service auditd
      block:

      - name: Gather the package facts
        ansible.builtin.package_facts:
          manager: auto

      - name: Enable auditd Service - Enable Service auditd
        ansible.builtin.systemd:
          name: auditd
          enabled: true
          state: started
          masked: false
        when:
        - '"audit" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-171-3.3.2
      - NIST-800-171-3.3.6
      - NIST-800-53-AC-2(g)
      - NIST-800-53-AC-6(9)
      - NIST-800-53-AU-10
      - NIST-800-53-AU-12(c)
      - NIST-800-53-AU-14(1)
      - NIST-800-53-AU-2(d)
      - NIST-800-53-AU-3
      - NIST-800-53-CM-6(a)
      - NIST-800-53-SI-4(23)
      - PCI-DSS-Req-10.1
      - PCI-DSSv4-10.2
      - PCI-DSSv4-10.2.1
      - enable_strategy
      - low_complexity
      - low_disruption
      - medium_severity
      - no_reboot_needed
      - service_auditd_enabled
      - special_service_block
      when:
      - '"kernel" in ansible_facts.packages'
      - '"audit" in ansible_facts.packages'
Remediation Puppet snippet ⇲
Complexity: | low
Disruption: | low
Reboot: | false
Strategy: | enable
    include enable_auditd

    class enable_auditd {
      service {'auditd':
        enable => true,
        ensure => 'running',
      }
    }
#### Rule Enable Auditing for Processes Which Start Prior to the Audit Daemon [ref]
To ensure all processes can be audited, even those which start prior to the audit daemon, add the argument `audit=1` to the default GRUB 2 command line for the Linux operating system. Configure the default Grub2 kernel command line to contain audit=1 as follows:
    # grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) audit=1"
Rationale: | Each process on the system carries an "auditable" flag which indicates whether its activities can be audited. Although `auditd` takes care of enabling this for all processes which launch after it does, adding the kernel argument ensures it is set for every process during boot.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_grub2_audit_argument
References: |
cis-csc | 1, 11, 12, 13, 14, 15, 16, 19, 3, 4, 5, 6, 7, 8
cjis | 5.4.1.1
cobit5 | APO10.01, APO10.03, APO10.04, APO10.05, APO11.04, APO12.06, APO13.01, BAI03.05, BAI08.02, DSS01.04, DSS02.02, DSS02.04, DSS02.07, DSS03.01, DSS05.02, DSS05.03, DSS05.04, DSS05.07, MEA01.01, MEA01.02, MEA01.03, MEA01.04, MEA01.05, MEA02.01
cui | 3.3.1
hipaa | 164.308(a)(1)(ii)(D), 164.308(a)(5)(ii)(C), 164.310(a)(2)(iv), 164.310(d)(2)(iii), 164.312(b)
isa-62443-2009 | 4.2.3.10, 4.3.2.6.7, 4.3.3.3.9, 4.3.3.5.8, 4.3.3.6.6, 4.3.4.4.7, 4.3.4.5.6, 4.3.4.5.7, 4.3.4.5.8, 4.4.2.1, 4.4.2.2, 4.4.2.4
isa-62443-2013 | SR 1.13, SR 2.10, SR 2.11, SR 2.12, SR 2.6, SR 2.8, SR 2.9, SR 3.1, SR 3.5, SR 3.8, SR 4.1, SR 4.3, SR 5.1, SR 5.2, SR 5.3, SR 6.1, SR 7.1, SR 7.6
iso27001-2013 | A.11.2.6, A.12.4.1, A.12.4.2, A.12.4.3, A.12.4.4, A.12.7.1, A.13.1.1, A.13.2.1, A.14.1.3, A.15.2.1, A.15.2.2, A.16.1.4, A.16.1.5, A.16.1.7, A.6.2.1, A.6.2.2
nist | AC-17(1), AU-14(1), AU-10, CM-6(a), IR-5(1)
nist-csf | DE.AE-3, DE.AE-5, ID.SC-4, PR.AC-3, PR.PT-1, PR.PT-4, RS.AN-1, RS.AN-4
ospp | FAU_GEN.1
pcidss | Req-10.3
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218, SRG-OS-000254-GPOS-00095
cis | 5.2.1.2
pcidss4 | 10.7.2, 10.7
Remediation OSBuild Blueprint snippet ⇲
    [customizations.kernel]
    append = "audit=1"
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q grub2-common; }; then

    if { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        KARGS_DIR="/usr/lib/bootc/kargs.d/"
        if grep -q -E "audit" "$KARGS_DIR/*.toml" ; then
            sed -i -E "s/^(\s*kargs\s*=\s*\[.*)\"audit=[^\"]*\"(.*]\s*)/\1\"audit=1\"\2/" "$KARGS_DIR/*.toml"
        else
            echo "kargs = [\"audit=1\"]" >> "$KARGS_DIR/10-audit.toml"
        fi
    else

        grubby --update-kernel=ALL --args=audit=1

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | medium
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-17(1)
      - NIST-800-53-AU-10
      - NIST-800-53-AU-14(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IR-5(1)
      - PCI-DSS-Req-10.3
      - PCI-DSSv4-10.7
      - PCI-DSSv4-10.7.2
      - grub2_audit_argument
      - low_disruption
      - low_severity
      - medium_complexity
      - reboot_required
      - restrict_strategy

    - name: Check if audit argument is already present in /etc/default/grub
      ansible.builtin.slurp:
        src: /etc/default/grub
      register: etc_default_grub
      when:
      - '"kernel" in ansible_facts.packages'
      - '"grub2-common" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-17(1)
      - NIST-800-53-AU-10
      - NIST-800-53-AU-14(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IR-5(1)
      - PCI-DSS-Req-10.3
      - PCI-DSSv4-10.7
      - PCI-DSSv4-10.7.2
      - grub2_audit_argument
      - low_disruption
      - low_severity
      - medium_complexity
      - reboot_required
      - restrict_strategy

    - name: Check if audit argument is already present
      ansible.builtin.command: /sbin/grubby --info=ALL
      register: grubby_info
      check_mode: false
      changed_when: false
      failed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"grub2-common" in ansible_facts.packages'
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-17(1)
      - NIST-800-53-AU-10
      - NIST-800-53-AU-14(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IR-5(1)
      - PCI-DSS-Req-10.3
      - PCI-DSSv4-10.7
      - PCI-DSSv4-10.7.2
      - grub2_audit_argument
      - low_disruption
      - low_severity
      - medium_complexity
      - reboot_required
      - restrict_strategy

    - name: Update grub defaults and the bootloader menu
      ansible.builtin.command: /sbin/grubby --update-kernel=ALL --args="audit=1"
      when:
      - '"kernel" in ansible_facts.packages'
      - '"grub2-common" in ansible_facts.packages'
      - (grubby_info.stdout is not search('audit=1')) or ((etc_default_grub['content']
        | b64decode) is not search('audit=1'))
      tags:
      - CJIS-5.4.1.1
      - NIST-800-171-3.3.1
      - NIST-800-53-AC-17(1)
      - NIST-800-53-AU-10
      - NIST-800-53-AU-14(1)
      - NIST-800-53-CM-6(a)
      - NIST-800-53-IR-5(1)
      - PCI-DSS-Req-10.3
      - PCI-DSSv4-10.7
      - PCI-DSSv4-10.7.2
      - grub2_audit_argument
      - low_disruption
      - low_severity
      - medium_complexity
      - reboot_required
      - restrict_strategy
#### Rule Extend Audit Backlog Limit for the Audit Daemon [ref]
To improve the kernel capacity to queue all log events, even those which occurred prior to the audit daemon, add the argument `audit_backlog_limit=8192` to the default GRUB 2 command line for the Linux operating system. Configure the default Grub2 kernel command line to contain audit_backlog_limit=8192 as follows:
    # grub2-editenv - set "$(grub2-editenv - list | grep kernelopts) audit_backlog_limit=8192"
Rationale: | audit_backlog_limit sets the queue length for audit events awaiting transfer to the audit daemon. Until the audit daemon is up and running, all log messages are stored in this queue. If the queue is overrun during boot process, the action defined by audit failure flag is taken.
Severity: | low
Rule ID: | xccdf_org.ssgproject.content_rule_grub2_audit_backlog_limit_argument
References: |
nist | CM-6(a)
ospp | FAU_STG.1, FAU_STG.3
os-srg | SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000254-GPOS-00095, SRG-OS-000341-GPOS-00132, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215
cis | 5.2.1.3
pcidss4 | 10.7.2, 10.7
Remediation OSBuild Blueprint snippet ⇲
    [customizations.kernel]
    append = "audit_backlog_limit=8192"
Remediation Shell script ⇲
    # Remediation is applicable only in certain platforms
    if rpm --quiet -q kernel && { rpm --quiet -q grub2-common; }; then

    var_audit_backlog_limit='8192'

    if { rpm --quiet -q kernel rpm-ostree bootc && ! rpm --quiet -q openshift-kubelet && { [ -f "/run/.containerenv" ] || [ -f "/.containerenv" ]; }; } ; then
        KARGS_DIR="/usr/lib/bootc/kargs.d/"
        if grep -q -E "audit_backlog_limit" "$KARGS_DIR/*.toml" ; then
            sed -i -E "s/^(\s*kargs\s*=\s*\[.*)\"audit_backlog_limit=[^\"]*\"(.*]\s*)/\1\"audit_backlog_limit=$var_audit_backlog_limit\"\2/" "$KARGS_DIR/*.toml"
        else
            echo "kargs = [\"audit_backlog_limit=$var_audit_backlog_limit\"]" >> "$KARGS_DIR/10-audit_backlog_limit.toml"
        fi
    else

        grubby --update-kernel=ALL --args=audit_backlog_limit=$var_audit_backlog_limit

    fi

    else
        >&2 echo 'Remediation is not applicable, nothing was done'
    fi
Remediation Ansible snippet ⇲
Complexity: | medium
Disruption: | low
Reboot: | true
Strategy: | restrict
    - name: Gather the package facts
      package_facts:
        manager: auto
      tags:
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-10.7
      - PCI-DSSv4-10.7.2
      - grub2_audit_backlog_limit_argument
      - low_disruption
      - low_severity
      - medium_complexity
      - reboot_required
      - restrict_strategy
    - name: XCCDF Value var_audit_backlog_limit # promote to variable
      set_fact:
        var_audit_backlog_limit: !!str 8192
      tags:
        - always

    - name: Check if audit_backlog_limit argument is already present in /etc/default/grub
      ansible.builtin.slurp:
        src: /etc/default/grub
      register: etc_default_grub
      when:
      - '"kernel" in ansible_facts.packages'
      - '"grub2-common" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-10.7
      - PCI-DSSv4-10.7.2
      - grub2_audit_backlog_limit_argument
      - low_disruption
      - low_severity
      - medium_complexity
      - reboot_required
      - restrict_strategy

    - name: Check if audit_backlog_limit argument is already present
      ansible.builtin.command: /sbin/grubby --info=ALL
      register: grubby_info
      check_mode: false
      changed_when: false
      failed_when: false
      when:
      - '"kernel" in ansible_facts.packages'
      - '"grub2-common" in ansible_facts.packages'
      tags:
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-10.7
      - PCI-DSSv4-10.7.2
      - grub2_audit_backlog_limit_argument
      - low_disruption
      - low_severity
      - medium_complexity
      - reboot_required
      - restrict_strategy

    - name: Update grub defaults and the bootloader menu
      ansible.builtin.command: /sbin/grubby --update-kernel=ALL --args="audit_backlog_limit={{
        var_audit_backlog_limit }}"
      when:
      - '"kernel" in ansible_facts.packages'
      - '"grub2-common" in ansible_facts.packages'
      - (grubby_info.stdout is not search('audit_backlog_limit=' ~ var_audit_backlog_limit))
        or ((etc_default_grub['content'] | b64decode) is not search('audit_backlog_limit='
        ~ var_audit_backlog_limit))
      tags:
      - NIST-800-53-CM-6(a)
      - PCI-DSSv4-10.7
      - PCI-DSSv4-10.7.2
      - grub2_audit_backlog_limit_argument
      - low_disruption
      - low_severity
      - medium_complexity
      - reboot_required
      - restrict_strategy

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