Vulnerability Discussion
Failure to restrict system access to authenticated users negatively impacts RHEL 8 security.
Check
Verify that unattended or automatic logon via ssh is disabled with the following command:
$ sudo grep -i PermitUserEnvironment /etc/ssh/sshd_config
PermitUserEnvironment no
If "PermitUserEnvironment" is set to "yes", is missing completely, or is commented out, this is a finding.
Fix
Configure RHEL 8 to allow the 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
The SSH daemon must be restarted for the changes to take effect. To restart the SSH daemon, run the following command:
$ sudo systemctl restart sshd.service