cis-ubuntu1804-v220-1-8-6

name	cis-ubuntu1804-v220-1-8-6
description	Ensure GDM automatic mounting of removable media is disabled
category	cis-networking
version	2.2.0
author	cyberstrike-official
tags	["cis","ubuntu","linux","ubuntu-18.04","gdm","gnome","automount","removable-media","dconf"]
cis_id	1.8.6
cis_benchmark	CIS Ubuntu Linux 18.04 LTS Benchmark v2.2.0
tech_stack	["ubuntu","linux"]
cwe_ids	[]
chains_with	[]
prerequisites	[]
severity_boost	{}

1.8.6 Ensure GDM automatic mounting of removable media is disabled (Automated)

Profile Applicability

• Level 1 - Server
• Level 2 - Workstation

Description

By default GNOME automatically mounts removable media when inserted as a convenience to the user.

Rationale

With automounting enabled anyone with physical access could attach a USB drive or disc and have its contents available in system even if they lacked permissions to mount it themselves.

Impact

The use of portable hard drives is very common for workstation users. If your organization allows the use of portable storage or media on workstations and physical access controls to workstations is considered adequate there is little value add in turning off automounting.

Audit Procedure

Command Line

Run the following script to verify automatic mounting is disabled:

#!/usr/bin/env bash

{
    l_pkgoutput="" l_output="" l_output2=""
    # Check if GNOME Desktop Manager is installed. If package isn't installed, recommendation is Not Applicable\n
    # determine system's package manager
    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"
    done
    
     [ -n  ]; 
         -e 
        
        l_kfile=
        l_kfile2=
        
         [ -f  ]; 
            l_gpname=.
         [ -f  ]; 
            l_gpname=.
        
        
         [ -n  ]; 
            l_gpdir=
            
             grep -Pq --  /etc/dconf/profile/*; 
                l_output=
            
                l_output2=
            
            
             [ -f  ]; 
                l_output=
            
                l_output2=
            
            
             [ -d  ]; 
                l_output=
            
                l_output2=
            
            
             grep -Pqrs --  ; 
                l_output=
            
                l_output2=
            
            
             grep -Pqs --  ; 
                l_output=
            
                l_output2=
            
        
            
            l_output2=
        
    
        l_output=
    
    
     [ -z  ]; 
         -e 
    
         -e 
        [ -n  ] &&  -e 
    
}