DISA STIGS Viewer

AlmaLinux OS 9 SSHD must not allow blank passwords.

Overview

Finding ID Version Rule ID IA Controls Severity
V-269374 ALMA-09-034120 SV-269374r1050257_rule   Medium
Description
If an account has an empty password, anyone could log on and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments. Satisfies: SRG-OS-000106-GPOS-00053, SRG-OS-000108-GPOS-00055
STIG Date
CloudLinux AlmaLinux OS 9 Security Technical Implementation Guide 2025-05-22

Details

Check Text (C-73405r1049574_chk)
Verify AlmaLinux OS 9 remote access using SSH prevents logging on with a blank password with the following command:

$ sshd -T | grep -i permitemptypasswords

permitemptypasswords no

If "PermitEmptyPasswords" is set to "yes", or the line is missing, this is a finding.
Fix Text (F-73306r1048499_fix)
Configure the SSH daemon to prevent users logging in with blank passwords.

Add the following line to "/etc/ssh/sshd_config", or uncomment the line and set the value to "yes":

PermitEmptyPasswords no

Alternatively, add the setting to an include file if the line "Include /etc/ssh/sshd_config.d/*.conf" is found at the top of the "/etc/ssh/sshd_config" file:

$ cat << EOF | tee /etc/ssh/sshd_config.d/emptypasswords.conf
PermitEmptyPasswords no
EOF

Restart the SSH daemon for the settings to take effect:

$ systemctl restart sshd.service