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

Overview

Finding IDVersionRule IDIA ControlsSeverity
V-269299ALMA-09-024770SV-269299r1050181_ruleCCI-000366medium
Description
If other users have access to modify user-specific SSH configuration files or read keys, they may be able to log into the system as another user.
STIGDate
CloudLinux AlmaLinux OS 9 Security Technical Implementation Guide2025-05-22

Details

Check Text (C-269299r1050181_chk)

Verify the SSH daemon performs strict mode checking of home directory configuration files with the following command: $ sshd -T | grep strictmodes strictmodes yes If the "StrictModes" keyword is set to "no", or no output is returned, this is a finding.

Fix Text (F-73231r1048274_fix)

To configure the SSH daemon to perform strict mode checking of home directory configuration files, add or modify the following line in "/etc/ssh/sshd_config", or uncomment the line and set the value to "yes": StrictModes 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 "StrictModes yes" > /etc/ssh/sshd_config.d/strictmodes.conf Restart the SSH daemon for the settings to take effect: $ systemctl restart sshd.service