18.9.30.1.1 (L1) Ensure 'Block NetBIOS-based discovery for domain controller location' is set to 'Enabled'

Information

This policy setting determines whether the Domain Controller (DC) location algorithm uses NetBIOS-based discovery for the Domain Controller's location.

The recommended state for this setting is: Enabled

NetBIOS is considered insecure because it doesn't perform authentication, and can allow remote attackers to trigger a denial of service by sending spoofed Name Conflicts or Name Release datagrams. This is also known as NetBIOS Name Server Protocol Spoofing.

Solution

To establish the recommended configuration via GP, set the following UI path to Enabled :

Computer Configuration\Policies\Administrative Templates\System\Net Logon\DC Locator DNS Records\Block NetBIOS-based discovery for domain controller location

Note: This Group Policy path is provided by the Group Policy template Netlogon.admx/adml that is included with the Microsoft Windows 11 Release 24H2 Administrative Templates (or newer).

Impact:

None - this is the default behavior.

See Also

https://workbench.cisecurity.org/benchmarks/21344

Item Details

Category: CONFIGURATION MANAGEMENT

References: 800-53|CM-6, 800-53|CM-7, CSCv7|9.2

Plugin: Windows

Control ID: c5ab4d85e999044f5ec40dbddef4a9f20f353f5ecbeb588a8b47f7530583d827