Cloud Linux AlmaLinux OS 9 Security Technical Implementation Guide

The Cloud Linux AlmaLinux OS 9 Security Technical Implementation Guide (V1 R8) has 439 STIG checks. New to STIG checklists? Read What is a STIG checklist?, CKL vs CKLB, and STIG vs SCAP benchmark.

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Severity

Version

V1 · R8

CurrentPublished Wed Sep 30 2026

AlmaLinux OS 9 SSH daemon must not allow known hosts authentication.

Cloud Linux AlmaLinux OS 9 Security Technical Implementation Guide

Assessment Title

Rule Text

AlmaLinux OS 9 SSH daemon must not allow known hosts authentication.

Description

Discussion Text

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.

New to STIG checklists? Read What is a STIG checklist? and CKL vs CKLB.

Objective

V-269267

Rule

SV-269267r1050149_rule

Severity

medium

Rule Version

ALMA-09-021140

Documentable

false

IA Controls

NIST SP 800-53

Rev 5

Assessment Procedure

Check Text

Verify the SSH daemon does not allow known hosts authentication with the following command:

$ sshd -T | grep ignoreuserknownhosts

ignoreuserknownhosts yes

If the value is returned as "no", this is a finding.

Implementation Procedure

Fix Text

Configure the SSH daemon to not allow known hosts authentication.

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

IgnoreUserKnownHosts yes

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 'IgnoreUserKnownHosts yes' > /etc/ssh/sshd_config.d/40-knownhosts.conf

Restart the SSH daemon for the settings to take effect:

$ systemctl restart sshd.service

STIG check 160 of 439 in the Cloud Linux AlmaLinux OS 9 STIG checklist

← Previous · V-269266AlmaLinux OS 9 SSH public host key files must have mode 0644 or less permissive.Next · V-269268 →AlmaLinux OS 9 SSH daemon must display the date and time of the last successful account logon upon an SSH logon.