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

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-258785	ESXI-80-000230	SV-258785r933416_rule		Medium

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

STIG	Date
VMware vSphere 8.0 ESXi Security Technical Implementation Guide	2023-10-11

Details

Check Text ( C-62525r933414_chk )
From an ESXi shell, run the following command: # esxcli system ssh server config list -k allowtcpforwarding or From a PowerCLI command prompt while connected to the ESXi host, run the following commands: $esxcli = Get-EsxCli -v2 $esxcli.system.ssh.server.config.list.invoke() \| Where-Object {$_.Key -eq 'allowtcpforwarding'} Example result: allowtcpforwarding no If "allowtcpforwarding" is not configured to "no", this is a finding.

Check Text ( C-62525r933414_chk )

From an ESXi shell, run the following command:

# esxcli system ssh server config list -k allowtcpforwarding

or

From a PowerCLI command prompt while connected to the ESXi host, run the following commands:

$esxcli = Get-EsxCli -v2
$esxcli.system.ssh.server.config.list.invoke() | Where-Object {$_.Key -eq 'allowtcpforwarding'}

Example result:

allowtcpforwarding no

If "allowtcpforwarding" is not configured to "no", this is a finding.

Fix Text (F-62434r933415_fix)
From an ESXi shell, run the following command: # esxcli system ssh server config set -k allowtcpforwarding -v no or From a PowerCLI command prompt while connected to the ESXi host, run the following commands: $esxcli = Get-EsxCli -v2 $arguments = $esxcli.system.ssh.server.config.set.CreateArgs() $arguments.keyword = 'allowtcpforwarding' $arguments.value = 'no' $esxcli.system.ssh.server.config.set.Invoke($arguments)

Fix Text (F-62434r933415_fix)

From an ESXi shell, run the following command:

# esxcli system ssh server config set -k allowtcpforwarding -v no

or

From a PowerCLI command prompt while connected to the ESXi host, run the following commands:

$esxcli = Get-EsxCli -v2
$arguments = $esxcli.system.ssh.server.config.set.CreateArgs()
$arguments.keyword = 'allowtcpforwarding'
$arguments.value = 'no'
$esxcli.system.ssh.server.config.set.Invoke($arguments)