Vulnerability Discussion
Configuring the system to disable IPv6 source routing protects against spoofing.
Check
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\Tcpip6\Parameters\
Value Name: DisableIpSourceRouting
Value Type: REG_DWORD
Value: 2
Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> MSS (Legacy) >> "MSS: (DisableIPSourceRouting IPv6) IP source routing protection level (protects against packet spoofing)" to "Highest protection, source routing is completely disabled".
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.