Detections
Analytics

4.6.4.1 (L1) Ensure 'Turn off multicast name resolution' is set to 'Enabled'

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This audit has been deprecated and will be removed in a future update.

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Information

Link-Local Multicast Name Resolution (LLMNR) is a secondary name resolution protocol. With LLMNR, queries are sent using multicast over a local network link on a single subnet from a client computer to another client computer on the same subnet that also has LLMNR enabled. LLMNR does not require a DNS server or DNS client configuration and provides name resolution in scenarios in which conventional DNS name resolution is not possible.

The recommended state for this setting is: Enabled

An attacker can listen on a network for these LLMNR (UDP/5355) or NBT-NS (UDP/137) broadcasts and respond to them, tricking the host into thinking that it knows the location of the requested system.

Note: To completely mitigate local name resolution poisoning, in addition to this setting, the properties of each installed NIC should also be set to Disable NetBIOS over TCP/IP (on the WINS tab in the NIC properties). Unfortunately, there is no global setting to achieve this that automatically applies to all NICs - it is a per-NIC setting that varies with different NIC hardware installations.

Solution

To establish the recommended configuration via configuration profiles, set the following Settings Catalog path to Enabled

Administrative Templates\Network\DNS Client\Turn off multicast name resolution

Impact:

In the event DNS is unavailable a system will be unable to request it from other systems on the same subnet.

See Also

https://workbench.cisecurity.org/benchmarks/21767

Item Details

References: CSCv7|9.2

Plugin: Windows

Control ID: e4adcf707aa4bfd8ce61a48bfdadded977fd76f4e6bc7bee38d2c26135d5f4d5