STIGQter STIGQter: STIG Summary: Red Hat Enterprise Linux 8 Security Technical Implementation Guide Version: 2 Release: 8 Benchmark Date: 01 Jul 2026:

RHEL 8 remote X connections for interactive users must be disabled unless to fulfill documented and validated mission requirements.

DISA Rule

SV-230555r1017317_rule

Vulnerability Number

V-230555

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

RHEL-08-040340

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Edit the "/etc/ssh/sshd_config" file to uncomment or add the line for the "X11Forwarding" keyword and set its value to "no" (this file may be named differently or be in a different location if using a version of SSH that is provided by a third-party vendor):

X11Forwarding no

The SSH service must be restarted for changes to take effect:

$ sudo systemctl restart sshd

Check Contents

Verify X11Forwarding is disabled with the following command:

$ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*x11forwarding'

X11Forwarding no

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

If conflicting results are returned, this is a finding.

Vulnerability Number

V-230555

Documentable

False

Rule Version

RHEL-08-040340

Severity Override Guidance

Verify X11Forwarding is disabled with the following command:

$ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*x11forwarding'

X11Forwarding no

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

If conflicting results are returned, this is a finding.

Check Content Reference

M

Target Key

2921