18.5.3 (L1) Ensure 'MSS: (DisableIPSourceRouting) IP source routing protection level' is set to 'Enabled: Highest protection, source routing is completely disabled'

Information

IP source routing is a mechanism that allows the sender to determine the IP route that a datagram should take through the network. It is recommended to configure this setting to Not Defined for enterprise environments and to Highest Protection for high security environments to completely disable source routing.

The recommended state for this setting is: Enabled: Highest protection, source routing is completely disabled

An attacker could use source routed packets to obscure their identity and location. Source routing allows a computer that sends a packet to specify the route that the packet takes.

Solution

To establish the recommended configuration via GP, set the following UI path to Enabled: Highest protection, source routing is completely disabled :

Computer Configuration\Policies\Administrative Templates\MSS (Legacy)\MSS: (DisableIPSourceRouting) IP source routing protection level

Note: This Group Policy path does not exist by default. An additional Group Policy template ( MSS-legacy.admx/adml ) is required - it is available from this TechNet blog post:

The MSS settings - Microsoft Security Guidance blog

Impact:

All incoming source routed packets will be dropped.

See Also

https://workbench.cisecurity.org/benchmarks/17610

Item Details

Category: SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|SC-7(12)

Plugin: Windows

Control ID: 7514bad630a43bbc719142b869d160d1925d6588c77b2a85ab15c4227f76e415