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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-281255	RHEL-10-700520	SV-281255r1184755_rule	CCI-001813	medium
Description
Kerberos authentication for SSH is often implemented using Generic Security Service Application Program Interface (GSSAPI). If Kerberos is enabled through SSH, the SSH daemon provides a means of access to the system's Kerberos implementation. Vulnerabilities in the system's Kerberos implementations may be subject to exploitation. OpenSSH uses the first occurrence of a keyword it sees, and drop-in files are read in lexicographical order at the start of the configuration. Red Hat recommends using drop-in files rather than changing base configuration files.
STIG			Date
Red Hat Enterprise Linux 10 Security Technical Implementation Guide			2026-03-11

Details

Check Text (C-281255r1184755_chk)

Verify RHEL 10 SSH daemons do not allow Kerberos 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*kerberosauthentication' /etc/ssh/sshd_config.d/10-stig.conf:KerberosAuthentication no Verify the runtime setting with the following command: $ sudo sshd -T | grep -i kerberosauthentication kerberosauthentication no If the "KerberosAuthentication" keyword is not set to "no" in a drop-in that lexicographically precedes 50-redhat.conf, no output is returned, and the use of Kerberos authentication has not been documented with the information system security officer, this is a finding.

Fix Text (F-85721r1166716_fix)

Configure RHEL 10 SSH daemons to not allow Kerberos authentication. In "/etc/ssh/sshd_config.d", create a drop file that will lexicographically precede 50-redhat.conf and add the following line: KerberosAuthentication no Restart the SSH service with the following command for the changes to take effect: $ sudo systemctl restart sshd.service