SV-253046r991579: Successful/unsuccessful uses of the "unix_update" in TOSS must generate an audit record. | Tri-Lab Operating System Stack (TOSS) 4 STIG SCAP Benchmark

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Assessment Title

Rule Text

Successful/unsuccessful uses of the "unix_update" in TOSS must generate an audit record.

Description

Discussion Text

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). "unix_update" is a helper program for the "pam_unix" module that updates the password for a given user. It is not intended to be run directly from the command line and logs a security violation if done so.

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

IA Controls

NIST SP 800-53

Not mappedCCI-000172

References

DPMS Target TOSS 4 DISA DPMS Target TOSS 4 5469

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.toss4os:def:253046
# Successful/unsuccessful uses of the "unix_update" in TOSS must generate an audit record.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# Audit invocations of /usr/sbin/unix_update
# textfilecontent54_object (textfilecontent54_test)
test_1() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)(?:\s+-S\s+all)?\s+-F\s+path=/usr/sbin/unix_update\s+(-F\s+perm=([rwa]*x[rwa]*)\s+)?-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)\S+)?\s*$' '/etc/audit/audit.rules' &>/dev/null
}

if test_1; then
  echo "PASS"
else
  echo "FAIL"
fi

Assessment Script Powered by AISandbox-executed

A standalone Shell script to assess this control automatically. Review before running it in your environment.

Syntax-checked and actually executed in an isolated sandbox (not the real system this checks) — confirmed to run without errors.

#!/bin/sh
# DISA STIG / SCAP compliance check for rule oval:mil.disa.stig.toss4os:def:253046

audit_rules_file="/etc/audit/rules.d/audit.rules"
audit_rule_pattern="^\\s*-a\\s+(always,exit|exit,always) -F path=/usr/sbin/unix_update -F perm=x -F auid>=1000 -F auid != unset -k privileged\\s*$"

if [ ! -f "$audit_rules_file" ]; then
  echo "PASS"
  exit 0
fi

if grep -P "$audit_rule_pattern" "$audit_rules_file" > /dev/null; then
  echo "PASS"
  exit 0
else
  echo "FAIL"
  exit 1
fi

Remediation

Configure the audit system to generate an audit event for any successful/unsuccessful uses of the "unix_update" by adding or updating the following rule in the "/etc/audit/rules.d/audit.rules" file:

-a always,exit -F path=/usr/sbin/unix_update -F perm=x -F auid>=1000 -F auid!=unset -k privileged

The audit daemon must be restarted for the changes to take effect.