The ESXi host SSH daemon must not permit tunnels.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-93997	ESXI-65-000025	SV-104083r1_rule		Medium

Description
OpenSSH has the ability to create network tunnels (layer-2 and layer-3) over an SSH connection. This function can provide similar convenience to a Virtual Private Network (VPN) with the similar risk of providing a path to circumvent firewalls and network ACLs.

STIG	Date
VMware vSphere 6.5 ESXi Security Technical Implementation Guide	2019-12-13

Details

Check Text ( C-93315r1_chk )
From an SSH session connected to the ESXi host, or from the ESXi shell, run the following command: # grep -i "^PermitTunnel" /etc/ssh/sshd_config If there is no output or the output is not exactly "PermitTunnel no", this is a finding.

Fix Text (F-100245r1_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": PermitTunnel no