Vulnerability Discussion

Allowing anonymous logon users (null session connections) to list all account names and enumerate all shared resources can provide a map of potential points to attack the system.

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: \SYSTEM\CurrentControlSet\Control\Lsa\

Value Name: RestrictAnonymous

Value Type: REG_DWORD
Value: 1

Fix

Configure the policy value for Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network access: Do not allow anonymous enumeration of SAM accounts and shares" to "Enabled".