Horizon3.ai
Horizon3.ai

Block remote MS-EVEN functionality with RPC Filters

If Microsoft EventLog Remoting Protocol (MS-EVEN) is not required, administrators should block the remote MS-EVEN functionality on the vulnerable host using RPC filters.

    1. Create a text file with the following content:
      rpc
      filter
      add rule layer=um actiontype=block
      add condition field=if_uuid matchtype=equal data=82273FDC-E32A-18C3-3F78-827929DC23EA
      add filter
      quit
    2. Use the netsh command line utility to import the RPC filter from an elevated administrator prompt:
      netsh -f <FILTER_FILE_NAME>
    3. To confirm the filters are in place, you can view the current RPC filters using the following command:
      netsh rpc filter show filter

See CERT Coordination Center Vulnerability Note VU:#405600 for additional details on protecting Active Directory Certificate Services from NTLM relay attacks.