BaselineWatch
Desk
Your fleet and your work Fleetyour releases and the hardware they run onTriagewhat needs a decisionWatchlistthe products and platforms you runSaved searchesthe lists you come back to
This instance Sourceswhat is read, how often, under what termsDigestthe daily or weekly summary, and alerts
How it is drawn Appearancethe look and the colour schemeBrandingthe mark this instance wears
Owner sign-in

RHEL-09-255160 RHEL 9 SSH daemon must perform strict mode checking of home directory configuration files.

DISA STIG library V2R10
All changes in this version
first version loaded CAT II

Maps to CM-6 via CCI-000366

Title

RHEL 9 SSH daemon must perform strict mode checking of home directory configuration files.

Control

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 the "StrictModes" keyword is set to "no", the returned line is commented out, or no output is returned, this is a finding.

Discussion

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

Related controls

CCI-000366

Fix

Configure the SSH daemon to perform strict mode checking of home directory configuration files. Add the following line to "/etc/ssh/sshd_config" or to a file in "/etc/ssh/sshd_config.d", or uncomment the line and set the value to "yes": StrictModes yes The SSH service must be restarted for changes to take effect: $ sudo systemctl restart sshd.service