PKU2U authentication using online identities must be prevented.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-21953	3.153	SV-25276r2_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
Windows 7 Security Technical Implementation Guide	2018-02-12

Details

Check Text ( C-60813r2_chk )
Analyze the system using the Security Configuration and Analysis snap-in. Expand the Security Configuration and Analysis tree view. Navigate to Local Policies >> Security Options. If the value for "Network Security: Allow PKU2U authentication requests to this computer to use online identities" is not set to "Disabled", this is a finding. The policy referenced configures the following registry value: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SYSTEM\CurrentControlSet\Control\LSA\pku2u\ Value Name: AllowOnlineID Type: REG_DWORD Value: 0

Check Text ( C-60813r2_chk )

Analyze the system using the Security Configuration and Analysis snap-in.
Expand the Security Configuration and Analysis tree view.
Navigate to Local Policies >> Security Options.

If the value for "Network Security: Allow PKU2U authentication requests to this computer to use online identities" is not set to "Disabled", this is a finding.

The policy referenced configures the following registry value:

Registry Hive: HKEY_LOCAL_MACHINE
Registry Path: \SYSTEM\CurrentControlSet\Control\LSA\pku2u\

Value Name: AllowOnlineID

Type: REG_DWORD
Value: 0

Fix Text (F-65545r2_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".