The Windows Firewall with Advanced Security must block unsolicited inbound connections when connected to a public network.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-17438	WNFWA-000020	SV-54906r1_rule	ECSC-1	High

Description
A firewall provides a line of defense against attack. To be effective, it must be enabled and properly configured. Unsolicited inbound connections may be malicious attempts to gain access to a system. Unsolicited inbound connections, for which there is no rule allowing the connection, will be blocked on a public network.

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

Details

Check Text ( C-48665r2_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: DefaultInboundAction Type: REG_DWORD Value: 1

Fix Text (F-47774r1_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 -> State, "Inbound connections" to "Block (default)".