Windows Server 2019 administrator accounts must not be enumerated during elevation.

STIG ID: WN19-CC-000240  |  SRG: SRG-OS-000134-GPOS-00068 |  Severity: medium |  CCI: CCI-001084 |  Vulnerability Id: V-205714 | 

Vulnerability Discussion

Enumeration of administrator accounts when elevating can provide part of the logon information to an unauthorized user. This setting configures the system to always require users to type in a username and password to elevate a running application.

Check

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: \SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\CredUI\

Value Name: EnumerateAdministrators

Type: REG_DWORD
Value: 0x00000000 (0)

Fix

Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Credential User Interface >> "Enumerate administrator accounts on elevation" to "Disabled".