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V-282713

CAT II (Medium)

The TOSS 5 SSH daemon must perform strict mode checking of home directory configuration files.

Rule ID

SV-282713r1201377_rule

STIG

Tri-Lab Operating System Stack (TOSS) 5 Security Technical Implementation Guide

Version

V1R1

CCIs

CCI-000366

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.

Check Content

Verify the SSH daemon performs strict mode checking of home directory configuration files using 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.

Fix Text

Configure the SSH daemon to perform strict mode checking of home directory configuration files.

Add the following line in "/etc/ssh/sshd_config" or uncomment the line and set the value to "yes":

StrictModes yes

Restart the SSH service for changes to take effect:

$ sudo systemctl restart sshd.service