The ESXi host must configure the firewall to restrict access to services running on the host.

An XCCDF Rule

Description

Unrestricted access to services running on an ESXi host can expose a host to outside attacks and unauthorized access. Reduce the risk by configuring the ESXi firewall to only allow access from authorized networks.

ID: SV-258794r1003574_rule
Version: ESXI-80-000239
Severity: Medium
References: CCI-000366
Updated: about 2 months ago

Remediation Templates

From the vSphere Client, go to Hosts and Clusters.

Select the ESXi Host >> Configure >> System >> Firewall.

Click "Edit...". For each user-configurable enabled service, uncheck the check box to "Allow connections from any IP address" and input the site-specific network(s) required.
The following example formats are acceptable:

192.168.0.0/24
192.168.1.2, 2001::1/64
fd3e:29a6:0a81:e478::/64

or

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

$esxcli = Get-EsxCli -v2
#This disables the allow all rule for the target service. The sshServer service is the target in this example.
$arguments = $esxcli.network.firewall.ruleset.set.CreateArgs()
$arguments.rulesetid = "sshServer"
$arguments.allowedall = $false
$esxcli.network.firewall.ruleset.set.Invoke($arguments)

#Next add the allowed IPs for the service. Note that executing the "vSphere Web Client" service this way may disable access but may be done through vCenter or through the console.
$arguments = $esxcli.network.firewall.ruleset.allowedip.add.CreateArgs()
$arguments.rulesetid = "sshServer"
$arguments.ipaddress = "10.0.0.0/8"
$esxcli.network.firewall.ruleset.allowedip.add.Invoke($arguments)

This must be done for each user-configurable enabled service.

The ESXi host must configure the firewall to restrict access to services running on the host.

Description

Remediation Templates

A Manual Procedure