Unattended or automatic login via ssh must not be allowed.

From Canonical Ubuntu 16.04 Security Technical Implementation Guide

Associated with: CCI-000366

SV-90513r2_rule Unattended or automatic login via ssh must not be allowed.

Vulnerability discussion

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

Check content

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

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

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