SV-258156r1106364: RHEL 9 must take action when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity. | Red Hat Enterprise Linux 9 STIG SCAP Benchmark

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Assessment Title

Rule Text

RHEL 9 must take action when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity.

Description

Discussion Text

If security personnel are not notified immediately when storage volume reaches a maximum of 75 percent utilization, they are unable to plan for audit record storage capacity expansion. The notification can be set to trigger at lower utilization thresholds at the information system security officer's (ISSO's) discretion.

How this relates to the STIG checklist: STIG vs SCAP benchmark.

IA Controls

NIST SP 800-53

Not mappedCCI-001855

References

DPMS Target Red Hat Enterprise Linux 9 DISA DPMS Target Red Hat Enterprise Linux 9 5551

Checks

DISA STIG (Manual Reference)

Verify RHEL 9 takes action when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity with the following command:

$ sudo grep -w space_left /etc/audit/auditd.conf

space_left = 25%

If the value of the "space_left" keyword is not set to 25 percent or greater of the storage volume allocated to audit logs, or if the line is commented out, ask the system administrator (SA) to indicate how the system is providing real-time alerts to the SA and ISSO. If the "space_left" value is not configured to the value 25 percent or more, this is a finding.

SCC Automation Reference

The reconstructed evaluation script behind this rule's OVAL check(s) — every module a compound check combines, with this rule's own concrete values and DISA's SCC tool's real per-module mechanism curated from static teardown of SCC releases.

#!/bin/bash
# Reconstructed from oval:mil.disa.stig.rhel9os:def:258156
# RHEL 9 must take action when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# /etc/audit/auditd.conf: space_left greater than or equal to 25%
# textfilecontent54_object (textfilecontent54_test)
test_1() {
  [ "$(sed -En 's/(?i)^\s*space_left\s*=\s*([\d]+)%\s*(?:#.*)?$/\1/p' '/etc/audit/auditd.conf')" -ge 25 ]
}
# /etc/audit/auditd.conf: space_left less than 100%
# textfilecontent54_object (textfilecontent54_test)
test_2() {
  [ "$(sed -En 's/(?i)^\s*space_left\s*=\s*([\d]+)%\s*(?:#.*)?$/\1/p' '/etc/audit/auditd.conf')" -lt 100 ]
}

if ( test_1 && test_2 ); then
  echo "PASS"
else
  echo "FAIL"
fi

Remediation

Configure RHEL 9 to initiate an action to notify the SA and ISSO (at a minimum) when allocated audit record storage volume reaches (at most) 75 percent of the repository maximum audit record storage capacity by adding/modifying the following line in the /etc/audit/auditd.conf file.

space_left  = 25%