The Windows Firewall with Advanced Security must block unicast responses to multicast or broadcast messages when connected to a public network.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-17441	WNFWA-000023	SV-54912r1_rule	ECSC-1	Medium

Description
A firewall provides a line of defense against attack. To be effective, it must be enabled and properly configured. Unicast responses to multicast or broadcast messages for a public network will be blocked. This helps minimize the risk of an attacker using broadcast or multicast traffic to deliver malicious payloads.

STIG	Date
Windows Firewall with Advanced Security Security Technical Implementation Guide	2014-01-07

Details

Check Text ( C-48669r2_chk )
Verify the registry value below. If this registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \Software\Policies\Microsoft\WindowsFirewall\PublicProfile\ Value Name: DisableUnicastResponsesToMulticastBroadcast Type: REG_DWORD Value: 1

Fix Text (F-47780r1_fix)
Configure the policy value for Computer Configuration -> Windows Settings -> Security Settings -> Windows Firewall with Advanced Security -> Windows Firewall with Advanced Security -> Windows Firewall Properties (this link will be in the right pane) -> Public Profile Tab -> Settings (select Customize) -> Unicast response, "Allow unicast response" to "No".