The Ubuntu operating system must not permit direct logons to the root account using remote access via SSH.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-215123	UBTU-16-030220	SV-215123r508033_rule		Medium

Description
Even though the communications channel may be encrypted, an additional layer of security is gained by extending the policy of not logging on directly as root. In addition, logging on with a user-specific account provides individual accountability of actions performed on the system.

STIG	Date
Canonical Ubuntu 16.04 LTS Security Technical Implementation Guide	2020-09-03

Details

Check Text ( C-16322r285237_chk )
Verify remote access using SSH prevents users from logging on directly as "root". Check that SSH prevents users from logging on directly as "root" with the following command: # grep PermitRootLogin /etc/ssh/sshd_config PermitRootLogin no If the "PermitRootLogin" keyword is set to "yes", is missing, or is commented out, this is a finding.

Fix Text (F-16320r285238_fix)
Configure the Ubuntu operating system to stop users from logging on remotely as the "root" user via SSH. Edit the appropriate "/etc/ssh/sshd_config" file to uncomment or add the line for the "PermitRootLogin" keyword and set its value to "no": PermitRootLogin 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

Fix Text (F-16320r285238_fix)

Configure the Ubuntu operating system to stop users from logging on remotely as the "root" user via SSH.

Edit the appropriate "/etc/ssh/sshd_config" file to uncomment or add the line for the "PermitRootLogin" keyword and set its value to "no":

PermitRootLogin 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