Windows Server 2025 must not allow anonymous enumeration of Security Account Manager (SAM) accounts.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
highV-278216SRG-OS-000480-GPOS-00227WN25-SO-000220SV-278216r1181354_rule2026-02-201

Description

Anonymous enumeration of SAM accounts allows anonymous logon 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: 0x00000001 (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".