TOSS 5 must not allow users to override SSH environment variables.

SSH environment options potentially allow users to bypass access restriction in some configurations.

Verify unattended or automatic logon via SSH is disabled 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*permituserenvironment'

PermitUserEnvironment no

If "PermitUserEnvironment" is set to "yes", is missing completely, or is commented out, this is a finding.

Configure the TOSS 5 SSH daemon to not allow unattended or automatic logon to the system.

Add or edit the following line in the "/etc/ssh/sshd_config" file:

PermitUserEnvironment no

Restart the SSH daemon for the setting to take effect:

$ sudo systemctl restart sshd.service