The ESXi host SSH daemon must not permit Kerberos authentication.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-93985	ESXI-65-000019	SV-104071r1_rule		Low

Description
Kerberos authentication for SSH is often implemented using 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 implementation may then be subject to exploitation. To reduce the attack surface of the system, the Kerberos authentication mechanism within SSH must be disabled for systems.

Description

Kerberos authentication for SSH is often implemented using 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 implementation may then be subject to exploitation. To reduce the attack surface of the system, the Kerberos authentication mechanism within SSH must be disabled for systems.

STIG	Date
VMware vSphere 6.5 ESXi Security Technical Implementation Guide	2020-03-27

Details

Check Text ( C-93303r1_chk )
From an SSH session connected to the ESXi host, or from the ESXi shell, run the following command: # grep -i "^KerberosAuthentication" /etc/ssh/sshd_config If there is no output or the output is not exactly "KerberosAuthentication no", this is a finding.

Fix Text (F-100233r1_fix)
From an SSH session connected to the ESXi host, or from the ESXi shell, add or correct the following line in "/etc/ssh/sshd_config": KerberosAuthentication no