Windows Server 2019 must prevent PKU2U authentication using online identities.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-205918 | WN19-SO-000280 | SV-205918r991589_rule | Medium |
| Description |
| PKU2U is a peer-to-peer authentication protocol. This setting prevents online identities from authenticating to domain-joined systems. Authentication will be centrally managed with Windows user accounts. |
| STIG | Date |
| Microsoft Windows Server 2019 Security Technical Implementation Guide | 2025-01-15 |
Details
| Check Text (C-6183r356116_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\pku2u\ Value Name: AllowOnlineID Type: REG_DWORD Value: 0x00000000 (0) |
| Fix Text (F-6183r356117_fix) |
| Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network security: Allow PKU2U authentication requests to this computer to use online identities" to "Disabled". |