The SSH client must be configured to not allow TCP forwarding.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-39249	GEN005516-ESXI5-703	SV-51065r1_rule		Low

Description
SSH TCP connection forwarding provides a mechanism to establish TCP connections proxied by the SSH server. 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 ESXi Server 5.0 Security Technical Implementation Guide	2013-09-12

Details

Check Text ( C-46513r1_chk )
Disable lock down mode. Enable the ESXi Shell. Check the SSH client configuration for allowed MACs. # grep Forward /etc/ssh/ssh_config | grep -v '^#' Re-enable lock down mode. If any forward list exists, this is a finding.

Fix Text (F-44228r1_fix)
Disable lock down mode. Enable the ESXi Shell. Edit the SSH client configuration and delete any/all existing Forward lists in the client configuration. # vi /etc/ssh/ssh_config Re-enable lock down mode.