STIGQter: STIG Summary: Red Hat Enterprise Linux 10 Security Technical Implementation Guide Version: 1 Release: 2 Benchmark Date: 01 Jul 2026:

RHEL 10 must be configured so that the Secure Shell (SSH) daemon does not allow known hosts authentication.

DISA Rule

SV-281257r1184757_rule

Vulnerability Number

V-281257

Group Title

SRG-OS-000445-GPOS-00199

Rule Version

RHEL-10-700540

Severity

CAT II

CCI(s)

• CCI-002696 - Verify correct operation of organization-defined security functions.

Weight

10

Fix Recommendation

Configure RHEL 10 SSH daemons to not allow known hosts authentication.

In "/etc/ssh/sshd_config.d", create a drop file that will lexicographically precede 50-redhat.conf and add the following line:

IgnoreUserKnownHosts yes

Restart the SSH service with the following command for the changes to take effect:

$ sudo systemctl restart sshd.service

Check Contents

Verify RHEL 10 SSH daemons do 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'
/etc/ssh/sshd_config.d/10-stig.conf:IgnoreUserKnownHosts yes

Verify the runtime setting with the following command:

$ sudo sshd -T | grep -i ignoreuserknownhosts
ignoreuserknownhosts yes

If the "IgnoreUserKnownHosts" keyword is not set to "yes" in a drop-in that lexicographically precedes 50-redhat.conf, or if no output is returned, this is a finding.

Vulnerability Number

V-281257

Documentable

False

Rule Version

RHEL-10-700540

Severity Override Guidance

Verify RHEL 10 SSH daemons do 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'
/etc/ssh/sshd_config.d/10-stig.conf:IgnoreUserKnownHosts yes

Verify the runtime setting with the following command:

$ sudo sshd -T | grep -i ignoreuserknownhosts
ignoreuserknownhosts yes

If the "IgnoreUserKnownHosts" keyword is not set to "yes" in a drop-in that lexicographically precedes 50-redhat.conf, or if no output is returned, this is a finding.

Check Content Reference

M

Target Key

5733