RHEL 9 must not allow a noncertificate trusted host SSH logon to the system.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-257992 | RHEL-09-255080 | SV-257992r1045047_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 | |||
| Red Hat Enterprise Linux 9 Security Technical Implementation Guide | 2025-05-14 | |||
Details
Check Text (C-257992r1045047_chk)
Verify the operating system does not allow a noncertificate trusted host SSH logon to the system 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*hostbasedauthentication'
HostbasedAuthentication no
If the "HostbasedAuthentication" keyword is not set to "no", is missing, or is commented out, this is a finding.
If the required value is not set, this is a finding.
Fix Text (F-61657r1045046_fix)
To configure RHEL 9 to not allow a noncertificate trusted host SSH logon to the system, add or modify the following line in "/etc/ssh/sshd_config" or in a file in "/etc/ssh/sshd_config.d".
HostbasedAuthentication no
Restart the SSH daemon for the settings to take effect:
$ sudo systemctl restart sshd.service