The ESXi host Secure Shell (SSH) daemon must be configured to not allow gateway ports.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| low | V-256391 | SRG-OS-000480-VMM-002000 | ESXI-70-000022 | SV-256391r959010_rule | 2025-02-11 | 1 |
Description
SSH Transmission Control Protocol (TCP) connection forwarding provides a mechanism to establish TCP connections proxied by the SSH server. This function can provide convenience similar to a virtual private network (VPN) with the similar risk of providing a path to circumvent firewalls and network Access Control Lists (ACLs). Gateway ports allow remote forwarded ports to bind to nonloopback addresses on the server.
ℹ️ Check
From an ESXi shell, run the following command:
# /usr/lib/vmware/openssh/bin/sshd -T|grep gatewayports
Expected result:
gatewayports 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":
GatewayPorts no