Windows Server 2019 • Release: 7 Benchmark Date: 05 Jan 2026

CAT II V-205918 WN19-SO-000280

Windows Server 2019 must prevent PKU2U authentication using online identities.

Documentable No
Rule ID SV-205918r991589_rule
CCI References
CCI-000366

Discussion

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.

Check Procedure

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 Action

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".