The Windows Firewall must block unicast responses to multicast or broadcast messages for the Public Profile.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
WN12-FW-000023	WN12-FW-000023	WN12-FW-000023_rule		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
Microsoft Windows Server 2012 Domain Controller Security Technical Implementation Guide	2013-07-25

Details

Check Text ( C-WN12-FW-000023_chk )
If the following 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 If a third-party firewall is used, verify a comparable setting has been implemented.

Fix Text (F-WN12-FW-000023_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". Configure a comparable setting if a third-party firewall is used.

Fix Text (F-WN12-FW-000023_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".

Configure a comparable setting if a third-party firewall is used.