The ESXi host Secure Shell (SSH) daemon must disable port forwarding.

While enabling Transmission Control Protocol (TCP) tunnels is a valuable function of sshd, this feature is not appropriate for use on the ESXi hypervisor.

From an ESXi shell, run the following command:

# /usr/lib/vmware/openssh/bin/sshd -T|grep allowtcpforwarding

Expected result:

allowtcpforwarding no

If the output does not match the expected result, this is a finding.

From an ESXi shell, add or correct the following line in "/etc/ssh/sshd_config":

AllowTcpForwarding no