The ESXi host must configure the firewall to block network traffic by default.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-258769	ESXI-80-000214	SV-258769r1003571_rule		Medium

Description
In addition to service-specific firewall rules, ESXi has a default firewall rule policy to allow or deny incoming and outgoing traffic. Reduce the risk of attack by ensuring this is set to deny incoming and outgoing traffic.

STIG	Date
VMware vSphere 8.0 ESXi Security Technical Implementation Guide	2024-07-11

Details

Check Text ( C-62509r1003533_chk )
From an ESXi shell, run the following command: # esxcli network firewall get or From a PowerCLI command prompt while connected to the ESXi host, run the following commands: $esxcli = Get-EsxCli -v2 $esxcli.network.firewall.get.invoke() If the "Default Action" does not equal "DROP", this is a finding. If "Enabled" does not equal "true", this is a finding.

Fix Text (F-62418r1003534_fix)
From an ESXi shell, run the following command: # esxcli network firewall set --default-action false --enabled true or From a PowerCLI command prompt while connected to the ESXi host, run the following commands: $esxcli = Get-EsxCli -v2 $arguments = $esxcli.network.firewall.set.CreateArgs() $arguments.enabled = $true $arguments.defaultaction = $false $esxcli.network.firewall.set.Invoke($arguments)

Fix Text (F-62418r1003534_fix)

From an ESXi shell, run the following command:

# esxcli network firewall set --default-action false --enabled true

or

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

$esxcli = Get-EsxCli -v2
$arguments = $esxcli.network.firewall.set.CreateArgs()
$arguments.enabled = $true
$arguments.defaultaction = $false
$esxcli.network.firewall.set.Invoke($arguments)