cis-ubuntu1604-v200-4-1-16

name	cis-ubuntu1604-v200-4-1-16
description	Ensure kernel module loading and unloading is collected
category	cis-logging
version	2.0.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-16.04","auditd","logging"]
cis_id	4.1.16
cis_benchmark	CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

CIS Ubuntu Linux 16.04 LTS Benchmark v2.0.0 - Control 4.1.16

Profile

• Level: 2 - Server
• Level: 2 - Workstation
• Assessment Status: Automated

Description

Monitor the loading and unloading of kernel modules. The programs insmod (install a kernel module), rmmod (remove a kernel module), and modprobe (a more sophisticated program to load and unload modules, as well as some other features) control loading and unloading of modules. The init_module (load a module) and delete_module (delete a module) system calls control loading and unloading of modules. Any execution of the loading and unloading module programs and system calls will trigger an audit record with an identifier of "modules".

Note: Reloading the auditd config to set active settings requires the auditd service to be restarted, and may require a system reboot.

Rationale

Monitoring the use of insmod, rmmod and modprobe could provide system administrators with evidence that an unauthorized user loaded or unloaded a kernel module, possibly compromising the security of the system. Monitoring of the init_module and delete_module system calls would reflect an unauthorized user attempting to use a different program to load and unload modules.

Impact

None.

Audit Procedure

Command Line

On a 32 bit system:

Run the following command to verify the rules are contained in a .rules file in the /etc/audit/rules.d/ directory:

grep modules /etc/audit/rules.d/*.rules

Verify output matches:

-w /sbin/insmod -p x -k modules
-w /sbin/rmmod -p x -k modules
-w /sbin/modprobe -p x -k modules
-a always,exit -F arch=b32 -S init_module -S delete_module -k modules

Run the following command to verify that rules are in the running auditd config:

auditctl -l | grep modules

Verify output matches:

-w /sbin/insmod -p x -k modules
-w /sbin/rmmod -p x -k modules
-w /sbin/modprobe -p x -k modules
-a always,exit -F arch=b32 -S init_module,delete_module -F key=modules

On a 64 bit system:

Run the following command to verify the rules are contained in a .rules file in the /etc/audit/rules.d/ directory:

grep modules /etc/audit/rules.d/*.rules

Verify output matches: