AlmaLinux OS 9 must not allow a noncertificate trusted host SSH logon to the system.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-269264 | ALMA-09-020810 | SV-269264r1050146_rule | CCI-000366 | medium |
| Description | ||||
| SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts. | ||||
| STIG | Date | |||
| CloudLinux AlmaLinux OS 9 Security Technical Implementation Guide | 2025-05-22 | |||
Details
Check Text (C-269264r1050146_chk)
Verify the operating system does not allow a noncertificate trusted host SSH logon to the system with the following command:
$ sshd -T | grep hostbasedauthentication
hostbasedauthentication no
If the "HostbasedAuthentication" keyword is not set to "no", this is a finding.
Fix Text (F-73196r1049409_fix)
Configure the AlmaLinux OS 9 SSH daemon to not allow a noncertificate trusted host SSH logon to the system with the following command:
Add the following line to "/etc/ssh/sshd_config", or uncomment the line and set the value to "no":
HostbasedAuthentication 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:
$ echo 'HostbasedAuthentication no' > /etc/ssh/sshd_config.d/40-hostbasedauthentication.conf
Restart the SSH daemon for the settings to take effect:
$ systemctl restart sshd.service