STIGQter: STIG Summary: Cloud Linux AlmaLinux OS 9 Security Technical Implementation Guide Version: 1 Release: 7 Benchmark Date: 01 Jul 2026:

AlmaLinux OS 9 SSH daemon must prevent remote hosts from connecting to the proxy display.

DISA Rule

SV-269271r1050153_rule

Vulnerability Number

V-269271

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

ALMA-09-021580

Severity

CAT II

CCI(s)

• CCI-000366 - Implement the security configuration settings.

Weight

10

Fix Recommendation

Configure the SSH daemon to prevent remote hosts from connecting to the proxy display.

Add the following line to "/etc/ssh/sshd_config", or uncomment the line and set the value to "yes":

X11UseLocalhost yes

Alternatively, add the setting to an include file if the line "Include /etc/ssh/sshd_config.d/*.conf" is found at the top of the "/etc/ssh/sshd_config" file:

$ echo 'X11UseLocalhost yes' > /etc/ssh/sshd_config.d/40-x11local.conf

Restart the SSH daemon for the settings to take effect:

$ systemctl restart sshd.service

Check Contents

Verify the SSH daemon prevents remote hosts from connecting to the proxy display with the following command:

$ sshd -T | grep x11uselocalhost

x11uselocalhost yes

If the value is returned as "no", this is a finding.

Vulnerability Number

V-269271

Documentable

False

Rule Version

ALMA-09-021580

Severity Override Guidance

Verify the SSH daemon prevents remote hosts from connecting to the proxy display with the following command:

$ sshd -T | grep x11uselocalhost

x11uselocalhost yes

If the value is returned as "no", this is a finding.

Check Content Reference

M

Target Key

5664