STIGQter STIGQter: STIG Summary: Red Hat Enterprise Linux 9 Security Technical Implementation Guide Version: 2 Release: 9 Benchmark Date: 01 Jul 2026:

RHEL 9 SSH daemon must disable remote X connections for interactive users.

DISA Rule

SV-258007r1045073_rule

Vulnerability Number

V-258007

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

RHEL-09-255155

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Configure the SSH daemon to not allow X11 forwarding.

Add the following line to "/etc/ssh/sshd_config" or to a file in "/etc/ssh/sshd_config.d", or uncomment the line and set the value to "no":

X11forwarding no

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

$ sudo systemctl restart sshd.service

Check Contents

Verify the SSH daemon does not allow X11Forwarding 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 value is returned as "yes", the returned line is commented out, or no output is returned, and X11 forwarding is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding.

Vulnerability Number

V-258007

Documentable

False

Rule Version

RHEL-09-255155

Severity Override Guidance

Verify the SSH daemon does not allow X11Forwarding 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 value is returned as "yes", the returned line is commented out, or no output is returned, and X11 forwarding is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding.

Check Content Reference

M

Target Key

5551