The Red Hat Enterprise Linux operating system must be configured so that the SSH daemon does not allow authentication using rhosts authentication.

STIG ID: RHEL-07-040350 |  SRG: SRG-OS-000480-GPOS-00227 |  Severity: medium |  CCI:  | Vulnerability Id: V-204590

Vulnerability Discussion

Configuring this setting for the SSH daemon provides additional assurance that remote logon via SSH will require a password, even in the event of misconfiguration elsewhere.

Check

Configure the SSH daemon to not allow authentication using known hosts authentication.

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

IgnoreRhosts yes

Fix

Verify the SSH daemon does not allow authentication using known hosts authentication.

To determine how the SSH daemon's "IgnoreRhosts" option is set, run the following command:

# grep -i IgnoreRhosts /etc/ssh/sshd_config

IgnoreRhosts yes

If the value is returned as "no", the returned line is commented out, or no output is returned, this is a finding.