CriticalSSHBLWK-SSH-003

SSH allows empty passwords

What this means

PermitEmptyPasswords is set to “‹permit empty passwords›” — any account with a blank password can log in over SSH with no credential at all.

How to fix it

Set PermitEmptyPasswords no in /etc/ssh/sshd_config and run systemctl restart sshd.

Check it yourself

Run a scan and look for BLWK-SSH-003 in the results:

bulwark scan

Installed the standalone CLI package instead of the app? The command is bulwarkctl.

How Bulwark decides

Bulwark reads sshd_config and reports this check when:

permit_empty_passwords == "yes"

If a value can't be read, Bulwark reports the check as undetermined rather than passing it. View the rule source.

References

• CIS Benchmark 5.2.11

Related checks

• SSH password authentication is enabled · BLWK-SSH-001
• SSH root login is permitted · BLWK-SSH-002
• SSH X11 forwarding is enabled · BLWK-SSH-004
• SSH TCP forwarding/tunneling is enabled · BLWK-SSH-005
• SSH permits user-set environment variables · BLWK-SSH-006
• SSH tun-device (layer 2/3) tunneling is enabled · BLWK-SSH-007