STIGQter STIGQter: STIG Summary: Canonical Ubuntu 24.04 LTS Security Technical Implementation Guide Version: 1 Release: 6 Benchmark Date: 01 Jul 2026:

Ubuntu 24.04 LTS must immediately terminate all network connections associated with SSH traffic at the end of the session or after 10 minutes of inactivity.

DISA Rule

SV-270743r1208702_rule

Vulnerability Number

V-270743

Group Title

SRG-OS-000163-GPOS-00072

Rule Version

UBTU-24-600010

Severity

CAT II

CCI(s)

Weight

10

Fix Recommendation

Configure Ubuntu 24.04 LTS to automatically terminate all network connections associated with SSH traffic at the end of a session or after a 10-minute period of inactivity.

In the file "/etc/ssh/sshd_config", set "ClientAliveInterval" to a value of "600" or less:

ClientAliveInterval 600

Restart SSH for the changes to take effect:

$ sudo systemctl restart ssh

Check Contents

Verify that all network connections associated with SSH traffic are automatically terminated at the end of the session or after 10 minutes of inactivity with the following command:

$ grep -ir ClientAliveInterval /etc/ssh/sshd_config*
/etc/ssh/sshd_config:ClientAliveInterval 600

If "ClientAliveInterval" does not exist, is not set to a value of "600" or less in "/etc/ssh/sshd_config", if conflicting results are returned, is commented out, or is missing, this is a finding.

Vulnerability Number

V-270743

Documentable

False

Rule Version

UBTU-24-600010

Severity Override Guidance

Verify that all network connections associated with SSH traffic are automatically terminated at the end of the session or after 10 minutes of inactivity with the following command:

$ grep -ir ClientAliveInterval /etc/ssh/sshd_config*
/etc/ssh/sshd_config:ClientAliveInterval 600

If "ClientAliveInterval" does not exist, is not set to a value of "600" or less in "/etc/ssh/sshd_config", if conflicting results are returned, is commented out, or is missing, this is a finding.

Check Content Reference

M

Target Key

5673