Anonymous enumeration of SAM accounts must not be allowed.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
highV-220929SRG-OS-000480-GPOS-00227WN10-SO-000145SV-220929r991589_rule2025-02-253
Description
Anonymous enumeration of SAM accounts allows anonymous log on users (null session connections) to list all accounts names, thus providing a list of potential points to attack the system.
ℹ️ 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: RestrictAnonymousSAM 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" to "Enabled".