The Windows Firewall must block unicast response to multicast or broadcast messages for the Domain Profile.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-17421	WN08-FW-000005	SV-48270r1_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 in the domain will be blocked. This helps minimize the risk of an attacker using broadcast or multicast traffic to deliver malicious payloads.

STIG	Date
Windows 8 Security Technical Implementation Guide	2013-10-01

Details

Check Text ( C-44948r1_chk )
If the following registry value does not exist or is not configured as specified, this is a finding: Registry Hive: HKEY_LOCAL_MACHINE Subkey: \Software\Policies\Microsoft\WindowsFirewall\DomainProfile\ Value Name: DisableUnicastResponsesToMulticastBroadcast Type: REG_DWORD Value: 1 Note: If a third-party firewall is used, document this with the IAO and mark the Windows firewall settings as NA. A comparable setting must still be implemented. The Secure Remote Computing STIGs may contain additional requirements for systems used remotely. Note: If the system is not a member of a domain, the Domain Profile requirements can be marked Not Applicable.

Check Text ( C-44948r1_chk )

If the following registry value does not exist or is not configured as specified, this is a finding:

Registry Hive: HKEY_LOCAL_MACHINE
Subkey: \Software\Policies\Microsoft\WindowsFirewall\DomainProfile\

Value Name: DisableUnicastResponsesToMulticastBroadcast

Type: REG_DWORD
Value: 1

Note: If a third-party firewall is used, document this with the IAO and mark the Windows firewall settings as NA. A comparable setting must still be implemented. The Secure Remote Computing STIGs may contain additional requirements for systems used remotely.

Note: If the system is not a member of a domain, the Domain Profile requirements can be marked Not Applicable.

Fix Text (F-41405r1_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) -> Domain Profile Tab -> Settings (select Customize) -> Unicast response, "Allow unicast response" to "No".