Host SSH daemon, if enabled, must not allow use of gateway ports

MediumLevel 1Automatedvmware

Description

When enabled, the SSH daemon on the host should have the gateway ports feature disabled to prevent remote hosts from forwarding connections. This is a hardening measure to ensure that the SSH service is securely configured against potential forwarding misuses. The audit reads /etc/ssh/sshd_config and requires GatewayPorts no (unset = OpenSSH default no). Runs in the ESXi Shell (busybox sh) as root.

How it is checked

Audit method: Shell command

shell

f=/etc/ssh/sshd_config; [ -r "$f" ] || exit 1
v=$(awk 'tolower($1)=="gatewayports" {print tolower($2); exit}' "$f")
case "$v" in '') echo compliant ;; no) echo compliant ;; *) echo "GatewayPorts $v" ;; esac

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

To remediate this recommendation, set GatewayPorts no in the supported ESXi SSH configuration. Restart SSH only during an authorized maintenance/admin window and verify the effective setting.

Properties

Operating systems: Any
Tags: vmwareesxiservices
Reference: CIS VMware ESXi 9.0 Benchmark v1.0.0 - 6.5.3 Host SSH daemon, if enabled, must not allow use of gateway ports

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target vmware