Title

Windows Server 2019 must prevent PKU2U authentication using online identities. (Cat II impact)

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 Content

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

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".

Additional Identifiers

Rule ID: SV-205918r991589_rule

Vulnerability ID: V-205918

Group Title: SRG-OS-000480-GPOS-00227

Expert Comments

CCIs tied to check.

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