Title

The system must be configured to ignore NetBIOS name release requests except from WINS servers. (Cat III impact)

Discussion

Configuring the system to ignore name release requests, except from WINS servers, prevents a denial of service (DoS) attack. The DoS consists of sending a NetBIOS name release request to the server for each entry in the server's cache, causing a response delay in the normal operation of the servers WINS resolution capability.

Check Content

Analyze the system using the Security Configuration and Analysis snap-in. Expand the Security Configuration and Analysis tree view. Navigate to Local Policies >> Security Options. If the value for "MSS: (NoNameReleaseOnDemand) Allow the computer to ignore NetBIOS name release requests except from WINS servers" is not set to "Enabled", this is a finding. The policy referenced configures the following registry value: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Services\Netbt\Parameters\ Value Name: NoNameReleaseOnDemand Value Type: REG_DWORD Value: 1

Fix Text

Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "MSS: (NoNameReleaseOnDemand) Allow the computer to ignore NetBIOS name release requests except from WINS servers" to "Enabled".

Additional Identifiers

Rule ID: SV-29369r2_rule

Vulnerability ID: V-4116

Group Title: Name-Release Attacks

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.