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

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-269299SRG-OS-000480-GPOS-00230ALMA-09-024770SV-269299r1050181_rule2025-02-201
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.
ℹ️ Check
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
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