NTLM must be prevented from falling back to a Null session.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
|---|---|---|---|---|
| V-225502 | WN12-SO-000062 | SV-225502r569185_rule | Medium |
| Description |
|---|
| NTLM sessions that are allowed to fall back to Null (unauthenticated) sessions may gain unauthorized access. |
| STIG | Date |
|---|---|
| Microsoft Windows Server 2012/2012 R2 Member Server Security Technical Implementation Guide | 2022-03-01 |
Details
| Check Text ( C-27201r471848_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: 0 |
| Fix Text (F-27189r471849_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". |