The ESXi host Secure Shell (SSH) daemon must not permit tunnels.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-256393 | ESXI-70-000025 | SV-256393r959010_rule | CCI-000366 | 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 Access Control Lists (ACLs). | ||||
| STIG | Date | |||
| VMware vSphere 7.0 ESXi Security Technical Implementation Guide | 2025-02-11 | |||
Details
Check Text (C-256393r959010_chk)
From an ESXi shell, run the following command:
# /usr/lib/vmware/openssh/bin/sshd -T|grep permittunnel
Expected result:
permittunnel no
If the output does not match the expected result, this is a finding.
Fix Text (F-60011r885959_fix)
From an ESXi shell, add or correct the following line in "/etc/ssh/sshd_config":
PermitTunnel no