RHEL 9 SSHD must not allow blank passwords.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-257984 | RHEL-09-255040 | SV-257984r1045026_rule | CCI-000766 | high |
| 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-000480-GPOS-00229, SRG-OS-000480-GPOS-00227 | ||||
| STIG | Date | |||
| Red Hat Enterprise Linux 9 Security Technical Implementation Guide | 2025-05-14 | |||
Details
Check Text (C-257984r1045026_chk)
Verify that RHEL 9 remote access using SSH prevents logging on with a blank password with the following command:
$ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*permitemptypasswords'
PermitEmptyPasswords no
If the "PermitEmptyPasswords" keyword is set to "yes", is missing, or is commented out, this is a finding.
Fix Text (F-61649r1045025_fix)
To configure the system to prevent SSH users from logging on with blank passwords edit the following line in "/etc/ssh/sshd_config" or in a file in "/etc/ssh/sshd_config.d":
PermitEmptyPasswords no
Restart the SSH daemon for the settings to take effect:
$ sudo systemctl restart sshd.service