Anonymous enumeration of SAM accounts must not be allowed.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-26283	WN08-SO-000051	SV-48508r2_rule	ECSC-1	High

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.

STIG	Date
Windows 8 / 8.1 Security Technical Implementation Guide	2015-06-16

Details

Check Text ( C-45159r2_chk )
Analyze the system using the Security Configuration and Analysis snap-in. (See "Performing Analysis with the Security Configuration and Analysis Snap-in" in the STIG Overview document.) Expand the Security Configuration and Analysis tree view. Navigate to Local Policies -> Security Options. If the value for "Network access: Do not allow anonymous enumeration of SAM accounts" is not set to "Enabled", this is a finding. The policy referenced configures the following registry value: Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \System\CurrentControlSet\Control\Lsa\ Value Name: RestrictAnonymousSAM Value Type: REG_DWORD Value: 1

Check Text ( C-45159r2_chk )

Analyze the system using the Security Configuration and Analysis snap-in. (See "Performing Analysis with the Security Configuration and Analysis Snap-in" in the STIG Overview document.)
Expand the Security Configuration and Analysis tree view.
Navigate to Local Policies -> Security Options.

If the value for "Network access: Do not allow anonymous enumeration of SAM accounts" is not set to "Enabled", this is a finding.

The policy referenced configures the following registry value:

Registry Hive: HKEY_LOCAL_MACHINE
Registry Path: \System\CurrentControlSet\Control\Lsa\

Value Name: RestrictAnonymousSAM

Value Type: REG_DWORD
Value: 1

Fix Text (F-41632r1_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".