The TOSS SSH daemon must perform strict mode checking of home directory configuration files.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-253106	TOSS-04-040650	SV-253106r824990_rule		Medium

Description
If other users have access to modify user-specific SSH configuration files, they may be able to log on to the system as another user.

STIG	Date
Tri-Lab Operating System Stack (TOSS) 4 Security Technical Implementation Guide	2022-08-29

Details

Check Text ( C-56559r824988_chk )
Verify the SSH daemon performs strict mode checking of home directory configuration files with the following command: $ sudo grep -i strictmodes /etc/ssh/sshd_config StrictModes yes If "StrictModes" is set to "no", is missing, or the returned line is commented out, this is a finding.

Fix Text (F-56509r824989_fix)
Configure SSH to perform strict mode checking of home directory configuration files. Uncomment the "StrictModes" keyword in "/etc/ssh/sshd_config" and set the value to "yes": StrictModes yes The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command: $ sudo systemctl restart sshd.service