The ESXi host Secure Shell (SSH) daemon must not permit tunnels.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-256393 | SRG-OS-000480-VMM-002000 | ESXI-70-000025 | SV-256393r959010_rule | 2025-02-11 | 1 |
| 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). |
| ℹ️ Check |
|---|
| 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 |
|---|
| From an ESXi shell, add or correct the following line in "/etc/ssh/sshd_config": PermitTunnel no |