Ensure SSH X11 forwarding is disabled

MoyenneNiveau 1Automatiséecos

Description

The X11Forwarding parameter provides the ability to tunnel X11 traffic through the connection to enable remote graphic connections. Disable X11 forwarding unless there is an operational requirement to use X11 applications directly. There is a small risk that the remote X11 servers of users who are logged in via SSH with X11 forwarding could be compromised by other users on the X11 server. Note that even if X11 forwarding is disabled, users can always install their own forwarders.

Méthode de vérification

Méthode d'audit: Commande shell

shell

alt0() { command -v grep >/dev/null 2>&1 || { echo "step1: grep not installed"; return 1; }; command -v sshd >/dev/null 2>&1 || { echo "step1: sshd not installed"; return 1; }; o=$(bash -c 'sshd -T | grep x11forwarding' 2>&1); printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'X11Forwarding no' || { echo step1: missing 'X11Forwarding no'; return 1; }; }; if alt0; then echo compliant; fi

Sortie attendue: compliant

Méthode de correction

Méthode de correction: Recommandation ou correctif d'infrastructure

Edit the /etc/ssh/sshd_config file to set the parameter as follows: X11Forwarding no

Propriétés

Systèmes d'exploitation: Tous
Étiquettes: container-optimized-oscosssh
Référence: CIS Google Container-Optimized OS Benchmark v1.2.0 - 5.1.6 Ensure SSH X11 forwarding is disabled

Vérifier cet hôte

Exécutez cette commande sur une machine que vous êtes autorisé à auditer. L'analyse est en lecture seule.

shell

tmaegis scan --target cos