Information
This policy setting allows local users to be enumerated on domain-joined computers.
The recommended state for this setting is: Disabled.
Rationale:
A malicious user could use this feature to gather account names of other users, that information could then be used in conjunction with other types of attacks such as guessing passwords or social engineering. The value of this countermeasure is small because a user with domain credentials could gather the same account information using other methods.
Solution
To establish the recommended configuration via GP, set the following UI path to Disabled:
Computer Configuration\Policies\Administrative Templates\System\Logon\Enumerate local users on domain-joined computers
Impact:
None - this is the default configuration.
Default Value:
Disabled. (The Logon UI will not enumerate local users on domain-joined computers.)