WN25-CC-000040 Windows Server 2025 source routing must be configured to the highest protection level to prevent Internet Protocol (IP) source routing.
All changes in this version
Maps to CM-6 via CCI-000366
Title
Windows Server 2025 source routing must be configured to the highest protection level to prevent Internet Protocol (IP) source routing.
Control
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: \SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\ Value Name: DisableIPSourceRouting Value Type: REG_DWORD Value: 0x00000002 (2)
Discussion
Configuring the system to disable IP source routing protects against spoofing.
Related controls
CCI-000366
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> MSS (Legacy) >> MSS: (DisableIPSourceRouting) IP source routing protection level (protects against packet spoofing) to "Enabled" with "Highest protection, source routing is completely disabled" selected. This policy setting requires the installation of the MSS-Legacy custom templates included with the STIG package. "MSS-Legacy.admx" and "MSS-Legacy.adml" must be copied to the \Windows\PolicyDefinitions and \Windows\PolicyDefinitions\en-US directories respectively.