Unattended or automatic login via ssh must not be allowed.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-75833	UBTU-16-030250	SV-90513r2_rule		High

Description
Failure to restrict system access to authenticated users negatively impacts Ubuntu operating system security.

STIG	Date
Canonical Ubuntu 16.04 LTS Security Technical Implementation Guide	2018-07-18

Details

Check Text ( C-75521r1_chk )
Verify that unattended or automatic login via ssh is disabled. Check that unattended or automatic login via ssh is disabled with the following command: # egrep '(Permit(.*?)(Passwords\|Environment))' /etc/ssh/sshd_config PermitEmptyPasswords no PermitUserEnvironment no If "PermitEmptyPasswords" or "PermitUserEnvironment" keywords are not set to "no", is missing completely, or they are commented out, this is a finding.

Check Text ( C-75521r1_chk )

Verify that unattended or automatic login via ssh is disabled.

Check that unattended or automatic login via ssh is disabled with the following command:

# egrep '(Permit(.*?)(Passwords|Environment))' /etc/ssh/sshd_config

PermitEmptyPasswords no
PermitUserEnvironment no

If "PermitEmptyPasswords" or "PermitUserEnvironment" keywords are not set to "no", is missing completely, or they are commented out, this is a finding.

Fix Text (F-82463r2_fix)
Configure the Ubuntu operating system to allow the SSH daemon to not allow unattended or automatic login to the system. Add or edit the following lines in the "/etc/ssh/sshd_config" file: PermitEmptyPasswords no 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