STIGQter STIGQter: STIG Summary: Canonical Ubuntu 22.04 LTS Security Technical Implementation Guide Version: 2 Release: 9 Benchmark Date: 01 Jul 2026:

Ubuntu 22.04 LTS must be configured so that remote X connections are disabled, unless to fulfill documented and validated mission requirements.

DISA Rule

SV-260529r1208685_rule

Vulnerability Number

V-260529

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

UBTU-22-255040

Severity

CAT I

CCI(s)

Weight

10

Fix Recommendation

Configure the SSH server to disable X11 forwarding.

Add or modify the following line in the "/etc/ssh/sshd_config" file:

X11Forwarding no

Restart SSH for the changes to take effect:

$ sudo systemctl restart ssh

Check Contents

Verify that X11 forwarding is disabled by using the following command:

$ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH 'x11forwarding'
/etc/ssh/sshd_config:X11Forwarding no

If "X11Forwarding" is set to "yes" and is not documented with the information system security officer (ISSO) as an operational requirement, is commented out, is missing, or conflicting results are returned, this is a finding.

Vulnerability Number

V-260529

Documentable

False

Rule Version

UBTU-22-255040

Severity Override Guidance

Verify that X11 forwarding is disabled by using the following command:

$ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH 'x11forwarding'
/etc/ssh/sshd_config:X11Forwarding no

If "X11Forwarding" is set to "yes" and is not documented with the information system security officer (ISSO) as an operational requirement, is commented out, is missing, or conflicting results are returned, this is a finding.

Check Content Reference

M

Target Key

5594