STIGQter: STIG Summary: Riverbed NetIM OS Security Technical Implementation Guide Version: 1 Release: 1 Benchmark Date: 11 Sep 2025:

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

DISA Rule

SV-275622r1147916_rule

Vulnerability Number

V-275622

Group Title

SRG-OS-000480-GPOS-00227

Rule Version

RIIM-OS-255040

Severity

CAT II

CCI(s)

• CCI-000366 - Implement the security configuration settings.

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 the SSH daemon for the changes to take effect:

$ sudo systemctl restart sshd.service

Check Contents

Verify 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 as an operational requirement, is commented out, is missing, or conflicting results are returned, this is a finding.

Vulnerability Number

V-275622

Documentable

False

Rule Version

RIIM-OS-255040

Severity Override Guidance

Verify 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 as an operational requirement, is commented out, is missing, or conflicting results are returned, this is a finding.

Check Content Reference

M

Target Key

5706