The ESXi host Secure Shell (SSH) daemon must be configured to not allow X11 forwarding.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-256392 | ESXI-70-000023 | SV-256392r959010_rule | Medium |
| Description |
| X11 forwarding over SSH allows for the secure remote execution of X11-based applications. This feature can increase the attack surface of an SSH connection. |
| STIG | Date |
| VMware vSphere 7.0 ESXi Security Technical Implementation Guide | 2024-12-16 |
Details
| Check Text (C-60067r885955_chk) |
| From an ESXi shell, run the following command: # /usr/lib/vmware/openssh/bin/sshd -T|grep x11forwarding Expected result: x11forwarding no If the output does not match the expected result, this is a finding. |
| Fix Text (F-60010r885956_fix) |
| From an ESXi shell, add or correct the following line in "/etc/ssh/sshd_config": X11Forwarding no |