NTLM must be prevented from falling back to a Null session.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
|---|---|---|---|---|
| V-73681 | WN16-SO-000330 | SV-88345r1_rule | Medium |
| Description |
|---|
| NTLM sessions that are allowed to fall back to Null (unauthenticated) sessions may gain unauthorized access. |
| STIG | Date |
|---|---|
| Windows Server 2016 Security Technical Implementation Guide | 2020-06-16 |
Details
| Check Text ( C-73763r1_chk ) |
|---|
| If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\LSA\MSV1_0\ Value Name: allownullsessionfallback Type: REG_DWORD Value: 0x00000000 (0) |
| Fix Text (F-80131r1_fix) |
|---|
| Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network security: Allow LocalSystem NULL session fallback" to "Disabled". |