System Audit Logs Must Have Mode 0640 or Less Permissive

An XCCDF Rule

Description

Determine 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

Configure the audit log to be protected from unauthorized read access by setting the correct permissive mode with the following command:

$ sudo chmod 0600 audit_log_file

By default, audit_log_file is "/var/log/audit/audit.log".

Rationale

If users can write to audit logs, audit trails can be modified or destroyed.

ID: xccdf_org.ssgproject.content_rule_file_permissions_var_log_audit
Severity: Medium
References: 1 11 12 13 14 15 16 18 19 3 4 5 6 7 8

5.4.1.1

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

3.3.1

CCI-000162 CCI-000163 CCI-000164 CCI-001314

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

SR 2.1 SR 2.10 SR 2.11 SR 2.12 SR 2.8 SR 2.9 SR 5.2 SR 6.1

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

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

AC-6(1) AU-9(4) CM-6(a)

DE.AE-3 DE.AE-5 PR.AC-4 PR.DS-5 PR.PT-1 RS.AN-1 RS.AN-4

Req-10.5

10.3.1

SRG-OS-000057-GPOS-00027 SRG-OS-000058-GPOS-00028 SRG-OS-000059-GPOS-00029 SRG-OS-000206-GPOS-00084

SRG-APP-000118-CTR-000240
Updated: about 1 year ago

# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ] && rpm --quiet -q audit; 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


chmod 0600 $FILE

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi

- 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-DSSv4-10.3.1
  - file_permissions_var_log_audit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Get audit log files
  command: grep -iw ^log_file /etc/audit/auditd.conf
  failed_when: false
  register: log_file_exists
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  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-DSSv4-10.3.1
  - file_permissions_var_log_audit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Parse log file line
  command: awk -F '=' '/^log_file/ {print $2}' /etc/audit/auditd.conf
  register: log_file_line
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - log_file_exists is not skipped and (log_file_exists.stdout | length > 0)
  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-DSSv4-10.3.1
  - file_permissions_var_log_audit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set default log_file if not set
  set_fact:
    log_file: /var/log/audit/audit.log
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (log_file_exists is skipped) or (log_file_exists is undefined) or (log_file_exists.stdout
    | length == 0)
  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-DSSv4-10.3.1
  - file_permissions_var_log_audit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Set log_file from log_file_line if not set already
  set_fact:
    log_file: '{{ log_file_line.stdout | trim }}'
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  - (log_file_exists is not skipped) and (log_file_line.stdout is defined) and (log_file_line.stdout
    | length > 0)
  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-DSSv4-10.3.1
  - file_permissions_var_log_audit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

- name: Apply mode to log file
  file:
    path: '{{ log_file }}'
    mode: 384
  failed_when: false
  when:
  - '"audit" in ansible_facts.packages'
  - ansible_virtualization_type not in ["docker", "lxc", "openvz", "podman", "container"]
  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-DSSv4-10.3.1
  - file_permissions_var_log_audit
  - low_complexity
  - low_disruption
  - medium_severity
  - no_reboot_needed
  - restrict_strategy

System Audit Logs Must Have Mode 0640 or Less Permissive

Description

Rationale

Remediation - Shell Script

Remediation - Ansible