Windows Server 2019 local users on domain-joined member servers must not be enumerated.

The username is one part of logon credentials that could be used to gain access to a system. Preventing the enumeration of users limits this information to authorized personnel.

This applies to member servers. For domain controllers and standalone or nondomain-joined systems, this is NA.

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\Policies\Microsoft\Windows\System\

Value Name: EnumerateLocalUsers

Type: REG_DWORD Value: 0x00000000 (0)

Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Logon >> "Enumerate local users on domain-joined computers" to "Disabled".