Detections
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1.7.8 Ensure GDM autorun-never is enabled

Information

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

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

Solution

Run the following script to set autorun-never to true for GDM users:

#!/usr/bin/env bash

{
 l_pkgoutput="" l_output="" l_output2=""
 l_gpname="local" # Set to desired dconf profile name (default is local)
 # Check if GNOME Desktop Manager is installed. If package isn't installed, recommendation is Not Applicable

 # determine system's package manager
 if command -v dpkg-query > /dev/null 2>&1; then
 l_pq="dpkg-query -W"
 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="$l_pkgoutput
 - Package: \"$l_pn\" exists on the system
 - checking configuration"
 done
 echo -e "$l_pkgoutput"
 # Check configuration (If applicable)
 if [ -n "$l_pkgoutput" ]; then
 echo -e "$l_pkgoutput"
 # Look for existing settings and set variables if they exist
 l_kfile="$(grep -Prils -- '^h*autorun-neverb' /etc/dconf/db/*.d)"
 # Set profile name based on dconf db directory ({PROFILE_NAME}.d)
 if [ -f "$l_kfile" ]; then
 l_gpname="$(awk -F/ '{split($(NF-1),a,".");print a[1]}' <<< "$l_kfile")"
 echo " - updating dconf profile name to \"$l_gpname\""
 fi
 [ ! -f "$l_kfile" ] && l_kfile="/etc/dconf/db/$l_gpname.d/00-media-autorun"
 # Check if profile file exists
 if grep -Pq -- "^h*system-db:$l_gpnameb" /etc/dconf/profile/*; then
 echo -e "
 - dconf database profile exists in: \"$(grep -Pl -- "^h*system-db:$l_gpnameb" /etc/dconf/profile/*)\""
 else
 [ ! -f "/etc/dconf/profile/user" ] && l_gpfile="/etc/dconf/profile/user" || l_gpfile="/etc/dconf/profile/user2"
 echo -e " - creating dconf database profile"
 {
 echo -e "
user-db:user"
 echo "system-db:$l_gpname"
 } >> "$l_gpfile"
 fi
 # create dconf directory if it doesn't exists
 l_gpdir="/etc/dconf/db/$l_gpname.d"
 if [ -d "$l_gpdir" ]; then
 echo " - The dconf database directory \"$l_gpdir\" exists"
 else
 echo " - creating dconf database directory \"$l_gpdir\""
 mkdir "$l_gpdir"
 fi
 # check autorun-never setting
 if grep -Pqs -- '^h*autorun-neverh*=h*trueb' "$l_kfile"; then
 echo " - \"autorun-never\" is set to true in: \"$l_kfile\""
 else
 echo " - creating or updating \"autorun-never\" entry in \"$l_kfile\""
 if grep -Psq -- '^h*autorun-never' "$l_kfile"; then
 sed -ri 's/(^s*autorun-nevers*=s*)(S+)(s*.*)$/1true 3/' "$l_kfile"
 else
 ! grep -Psq -- '^h*[org/gnome/desktop/media-handling]b' "$l_kfile" && echo '[org/gnome/desktop/media-handling]' >> "$l_kfile"
 sed -ri '/^s*[org/gnome/desktop/media-handling]/a \nautorun-never=true' "$l_kfile"
 fi
 fi
 else
 echo -e "
 - GNOME Desktop Manager package is not installed on the system
 - Recommendation is not applicable"
 fi
 # update dconf database
 dconf update
}

See Also

https://workbench.cisecurity.org/benchmarks/15965

Item Details

Category: MEDIA PROTECTION

References: 800-53|MP-7, CSCv7|8.5

Plugin: Unix

Control ID: 3d530a42c474dd376622c44d9623c87e2ba48e1bb1d3240970a3a364cb4342b0