SV-219297r991586: The Ubuntu operating system must generate records for successful/unsuccessful uses of delete_module syscall and when unloading dynamic kernel modules. | Canonical Ubuntu 18.04 LTS STIG SCAP Benchmark

Loading benchmark…

Assessment Title

Rule Text

The Ubuntu operating system must generate records for successful/unsuccessful uses of delete_module syscall and when unloading dynamic kernel modules.

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). Satisfies: SRG-OS-000064-GPOS-00033, SRG-OS-000471-GPOS-00216

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

IA Controls

NIST SP 800-53

Not mappedCCI-000172V-100817SV-109921

References

DPMS Target Canonical Ubuntu 18.04 LTS DISA DPMS Target Canonical Ubuntu 18.04 LTS 4055

Checks

DISA STIG (Manual Reference)

Verify if the Ubuntu operating system is configured to audit the "delete_module" syscall, by running the following command:

# sudo auditctl -l | egrep delete_module

-a always,exit -F arch=b64 -S delete_module -F key=modules
-a always,exit -F arch=b32 -S delete_module -F key=modules

If the command does not return lines that match the example or the lines are commented out, this is a finding.

Notes:
For 32-bit architectures, only the 32-bit specific output lines from the commands are required.
The '-k' allows for specifying an arbitrary identifier and the string after it does not need to match the example output above.

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.ubuntu1804:def:237
# The Ubuntu operating system must generate records for successful/unsuccessful uses of delete_module syscall and when unloading dynamic kernel modules.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# auditd package is installed
# dpkginfo_object (dpkginfo_test)
test_1() {
  grep -A1 '^Package: auditd$' /var/lib/dpkg/status &>/dev/null
}
# check for running auditd
# process58_object (process58_test)
test_2() {
  ps -eo args | grep -P '^\/sbin\/auditd\b' &>/dev/null
}
# Audit 32-bit invocations of delete_module syscall
# textfilecontent54_object (textfilecontent54_test)
test_3() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S[\s]+delete_module[\s]+|([\s]+|[,])delete_module([\s]+|[,])).*)((-F\s+-k\s+|-F\s+key=)\S+)?\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# Audit 64-bit invocations of delete_module syscall
# textfilecontent54_object (textfilecontent54_test)
test_4() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S[\s]+delete_module[\s]+|([\s]+|[,])delete_module([\s]+|[,])).*)((-F\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.ubuntu1804:def:237 STIG compliance check
if [ ! -f "/usr/bin/auditd" ]; then echo "FAIL"; exit 1; fi
if ! pgrep -f '^/sbin/auditd' > /dev/null; then echo "FAIL"; exit 1; fi
if ! grep -q '^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b32\\s+-S\\s+delete_module\\s*$' /etc/audit/rules.d/stig.rules; then echo "FAIL"; exit 1; fi
if ! grep -q '^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b64\\s+-S\\s+delete_module\\s*$' /etc/audit/rules.d/stig.rules; then echo "FAIL"; exit 1; fi
echo "PASS"; exit 0

Remediation

Configure the Ubuntu operating system to generate an audit event for any use of the delete_module system call.

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

-a always,exit -F arch=b32 -S delete_module -F key=modules
-a always,exit -F arch=b64 -S delete_module -F key=modules

Notes: For 32-bit architectures, only the 32-bit specific entries are required. 
The "root" account must be used to view/edit any files in the /etc/audit/rules.d/ directory.

In order to reload the rules file, issue the following command:

# sudo augenrules --load