cis-ubuntu1804-v220-1-8-9

name	cis-ubuntu1804-v220-1-8-9
description	Ensure GDM autorun-never is not overridden
category	cis-networking
version	2.2.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-18.04","gdm","gnome","autorun-never","lockdown","dconf"]
cis_id	1.8.9
cis_benchmark	CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

1.8.9 Ensure GDM autorun-never is not overridden (Automated)

Profile Applicability

• Level 1 - Server
• Level 1 - Workstation

Description

The autorun-never setting allows the GNOME Desktop Display Manager to disable autorun through GDM.

By using the lockdown mode in dconf, you can prevent users from changing specific settings.

To lock down a dconf key or subpath, create a locks subdirectory in the keyfile directory. The files inside this directory contain a list of keys or subpaths to lock. Just as with the keyfiles, you may add any number of files to this directory.

Example Lock File:

# Lock desktop media-handling settings
/org/gnome/desktop/media-handling/autorun-never

Rationale

Malware on removable media may taking advantage of Autorun features when the media is inserted into a system and execute.

Audit Procedure

Command Line

Run the following script to verify that autorun-never=true cannot be overridden:

#!/usr/bin/env bash

{
    # Check if GNOME Desktop Manager is installed. If package isn't installed, recommendation is Not Applicable\n
    # determine system's package manager
    l_pkgoutput=""
    if command -v dpkg-query > /dev/null 2>&1; then
        l_pq="dpkg-query -s"
    elif command -v rpm > /dev/null 2>&1; then
        l_pq="rpm -q"
    fi
    # Check if GDM is installed
    l_pcl="gdm gdm3" # Space separated list of packages to check
    for l_pn in $l_pcl; do
        $l_pq "$l_pn" > /dev/null 2>&1 && l_pkgoutput="$l_pkgoutput\n - Package: \"$l_pn\" exists on the system\n - checking configuration"
    
    
     [ -n  ]; 
        l_output= l_output2=
        
        l_kfd=. 
         [ -d  ];  
             grep -Prisq  ; 
                l_output=
            
                l_output2=
            
        
            l_output2=
        
    
        l_output=
    
    
    [ -n  ] &&  -e 
     [ -z  ]; 
         -e 
    
         -e 
        [ -n  ] &&  -e 
    
}