The SSH daemon must be configured to not allow gateway ports.

From VMware ESXi Server 5.0 Security Technical Implementation Guide

Associated with: CCI-000366

SV-51066r2_rule The SSH daemon must be configured to not allow gateway ports.

Vulnerability discussion

SSH TCP connection forwarding provides a mechanism to establish TCP connections proxied by the SSH server. 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 ACLs. Gateway ports allow remote forwarded ports to bind to non-loopback addresses on the server.

Check content

Disable lock down mode. Enable the ESXi Shell. Execute the following command(s): # grep -i GatewayPorts /etc/ssh/sshd_config If "GatewayPorts" is not set to "no", this is a finding. Re-enable lock down mode.

Fix text

Disable lock down mode. Enable the ESXi Shell. Execute the following command(s): # vi /etc/ssh/sshd_config Add/modify the attribute line entry to the following (quotes for emphasis only): "GatewayPorts no" Re-enable lock down mode.

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