The OL 8 SSH daemon must perform strict mode checking of home directory configuration files.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-248603	OL08-00-010500	SV-248603r991589_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
Oracle Linux 8 Security Technical Implementation Guide	2024-06-04

Details

Check Text ( C-52037r951563_chk )
Verify the SSH daemon performs strict mode checking of home directory configuration files 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*strictmodes' StrictModes yes If "StrictModes" is set to "no" or is missing, or if the returned line is commented out, this is a finding. If conflicting results are returned, this is a finding.

Check Text ( C-52037r951563_chk )

Verify the SSH daemon performs strict mode checking of home directory configuration files 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*strictmodes'

StrictModes yes

If "StrictModes" is set to "no" or is missing, or if the returned line is commented out, this is a finding.

If conflicting results are returned, this is a finding.

Fix Text (F-51991r779374_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