SV-39354r1: The at.allow file must be group-owned by system, bin, sys, or cron. | AIX 6.1 SECURITY TECHNICAL IMPLEMENTATION GUIDE

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Assessment Title

Rule Text

The at.allow file must be group-owned by system, bin, sys, or cron.

Description

Discussion Text

If the group-owner of the at.allow file is not set to system, bin, sys, or cron, unauthorized users could be allowed to view or edit the list of users permitted to run at jobs. Unauthorized modification could result in Denial of Service to authorized at users or provide unauthorized users with the ability to run at jobs.

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

IA Controls

NIST SP 800-53

Not mappedCCI-000225

Additional Details

Responsibility

System Administrator

IA Controls

ECLP-1

References

DPMS Target AIX 6.1 DISA DPMS Target AIX 6.1 2176

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.fso.aix11:def:194
# The at.allow file must be group-owned by system, bin, sys, or cron.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# Check group-ownership /var/adm/cron/at.allow
# file_object (file_test)
test_1() {
  ( [ "$(stat -c '%g' '/var/adm/cron/at.allow')" -eq 0 ] ) || ( [ "$(stat -c '%g' '/var/adm/cron/at.allow')" -eq 2 ] ) || ( [ "$(stat -c '%g' '/var/adm/cron/at.allow')" -eq 3 ] ) || ( [ "$(stat -c '%g' '/var/adm/cron/at.allow')" -eq 8 ] )
}

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
# OVAL Definition: oval:mil.disa.fso.aix11:def:194
file="/var/adm/cron/at.allow"
if [ ! -f "$file" ]; then echo "PASS"; exit 0; fi
if [ ! -g "$file" ]; then echo "FAIL"; exit 1; fi
gid=$(stat -c "%g" "$file")
if [ "$gid" = "0" ] || [ "$gid" = "2" ] || [ "$gid" = "3" ] || [ "$gid" = "8" ]; then echo "PASS"; exit 0; else echo "FAIL"; exit 1; fi

Remediation

Change the group owner of the at.allow file to sys, system, bin, or cron. 
Procedure: 
# chgrp cron /var/adm/cron/at.allow