SV-204545r958422: The Red Hat Enterprise Linux operating system must audit all uses of the chage command. | Red Hat Enterprise Linux 7 STIG SCAP Benchmark

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Assessment Title

Rule Text

The Red Hat Enterprise Linux operating system must audit all uses of the chage command.

Description

Discussion Text

Reconstruction of harmful events or forensic analysis is not possible if audit records do not contain enough information. At a minimum, the organization must audit the full-text recording of privileged password commands. The organization must maintain audit trails in sufficient detail to reconstruct events to determine the cause and impact of compromise. When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. Satisfies: SRG-OS-000042-GPOS-00020, SRG-OS-000392-GPOS-00172, SRG-OS-000471-GPOS-00215

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

IA Controls

NIST SP 800-53

Not mappedCCI-000135Not mappedCCI-000172Not mappedCCI-002884SV-86779V-72155

References

DPMS Target Red Hat Enterprise Linux 7 DISA DPMS Target Red Hat Enterprise Linux 7 2899

Checks

DISA STIG (Manual Reference)

Verify the operating system generates audit records when successful/unsuccessful attempts to use the "chage" command occur.

Check the file system rule in "/etc/audit/audit.rules" with the following command:

$ sudo grep -w "/usr/bin/chage" /etc/audit/audit.rules

-a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-passwd

If the command does not return any output, 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.rhel7:def:715
# The Red Hat Enterprise Linux operating system must audit all uses of the chage command.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# audit augenrules
# textfilecontent54_object (textfilecontent54_test)
test_1() {
  grep -Pq '^ExecStartPost=\-\/sbin\/augenrules.*$' '/usr/lib/systemd/system/auditd.service' &>/dev/null
}
# audit augenrules chage
# textfilecontent54_object (textfilecontent54_test)
test_2() {
  grep -rqP --include='*.rules' '^[\s]*-a[\s]+always,exit[\s]+-F[\s]+path=\/usr\/bin\/chage[\s]+(-F[\s]+perm=([rwa]*x[rwa]*)[\s]+)?-F[\s]+auid>=1000[\s]+-F[\s]+auid!=(?:4294967295|-1|unset)[\s]+(-k[\s]+|-F[\s]+key=)[\S]+[\s]*$' '/etc/audit/rules.d' &>/dev/null
}
# audit auditctl
# textfilecontent54_object (textfilecontent54_test)
test_3() {
  grep -Pq '^ExecStartPost=\-\/sbin\/auditctl.*$' '/usr/lib/systemd/system/auditd.service' &>/dev/null
}
# audit auditctl chage
# textfilecontent54_object (textfilecontent54_test)
test_4() {
  grep -Pq '^[\s]*-a[\s]+always,exit[\s]+-F[\s]+path=\/usr\/bin\/chage[\s]+(-F[\s]+perm=([rwa]*x[rwa]*)[\s]+)?-F[\s]+auid>=1000[\s]+-F[\s]+auid!=(?:4294967295|-1|unset)[\s]+(-k[\s]+|-F[\s]+key=)[\S]+[\s]*$' '/etc/audit/audit.rules' &>/dev/null
}

if ( ( test_1 && test_2 ) || ( test_3 && test_4 ) ); 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
# oval:mil.disa.stig.rhel7:def:715 compliance check script

if [ ! -f "/usr/lib/systemd/system/auditd.service" ]; then
  echo "FAIL"
  exit 1
fi

if grep -q "^ExecStartPost=-\\/sbin\\/augenrules.*$" /usr/lib/systemd/system/auditd.service; then

  if [ ! -f "/etc/audit/rules.d/audit.rules" ]; then
    echo "FAIL"
    exit 1
  fi

  if grep -q "^[\\s]*-a[\\s]+always,exit[\\s]+-F[\\s]+path=\\/usr\\/bin\\/chage[\\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/rules.d/audit.rules ]; then
    echo "PASS"
    exit 0
  else
    echo "FAIL"
    exit 1
  fi
else
  echo "FAIL"
  exit 1
fi

Remediation

Configure the operating system to generate audit records when successful/unsuccessful attempts to use the "chage" command occur.

Add or update the following rule in "/etc/audit/rules.d/audit.rules":

-a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-passwd

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