RHEL 9 SSH daemon must not allow known hosts authentication.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-258006 | RHEL-09-255150 | SV-258006r1045071_rule | CCI-000366 | medium |
| Description | ||||
| Configuring the IgnoreUserKnownHosts setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere. | ||||
| STIG | Date | |||
| Red Hat Enterprise Linux 9 Security Technical Implementation Guide | 2025-05-14 | |||
Related Frameworks
4 paths across 3 frameworks
Related Frameworks
NIST 800-531 mapping
CM-6
1.00
- DISA · 2 · disa_xccdf · related
- DISA · 2025-01-23 · disa_cci_list · equivalent
NIST 800-1712 mappings
3.4.1
1.00
- DISA · 2 · disa_xccdf · related
- DISA · 2025-01-23 · disa_cci_list · equivalent
- NIST · Rev 2 (Feb 2020, errata Jan 2021) · nist_800_171_app_d · equivalent
3.4.2
1.00
- DISA · 2 · disa_xccdf · related
- DISA · 2025-01-23 · disa_cci_list · equivalent
- NIST · Rev 2 (Feb 2020, errata Jan 2021) · nist_800_171_app_d · equivalent
CCI1 mapping
CCI-000366
1.00
- DISA · 2 · disa_xccdf · related
Details
Check Text (C-258006r1045071_chk)
Verify the SSH daemon does not allow known hosts authentication 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*ignoreuserknownhosts'
IgnoreUserKnownHosts yes
If the value is returned as "no", the returned line is commented out, or no output is returned, this is a finding.
Fix Text (F-61671r1045070_fix)
Configure the SSH daemon to not allow known hosts authentication.
Add the following line to "/etc/ssh/sshd_config" or to a file in "/etc/ssh/sshd_config.d", or uncomment the line and set the value to "yes":
IgnoreUserKnownHosts yes
The SSH service must be restarted for changes to take effect:
$ sudo systemctl restart sshd.service