Windows Server 2019 must restrict remote calls to the Security Account Manager (SAM) to Administrators on domain-joined member servers and standalone systems.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-93045	WN19-MS-000060	SV-103133r1_rule		Medium

Description
The Windows SAM stores users' passwords. Restricting Remote Procedure Call (RPC) connections to the SAM to Administrators helps protect those credentials.

STIG	Date
Windows Server 2019 Security Technical Implementation Guide	2019-07-09

Details

Check Text ( C-92363r1_chk )
This applies to member servers and standalone systems; it is NA for domain controllers. 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: RestrictRemoteSAM Value Type: REG_SZ Value: O:BAG:BAD:(A;;RC;;;BA)

Fix Text (F-99291r1_fix)
Navigate to the policy Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network access: Restrict clients allowed to make remote calls to SAM". Select "Edit Security" to configure the "Security descriptor:". Add "Administrators" in "Group or user names:" if it is not already listed (this is the default). Select "Administrators" in "Group or user names:". Select "Allow" for "Remote Access" in "Permissions for "Administrators". Click "OK". The "Security descriptor:" must be populated with "O:BAG:BAD:(A;;RC;;;BA) for the policy to be enforced.

Fix Text (F-99291r1_fix)

Navigate to the policy Computer Configuration >> Windows Settings >> Security Settings >> Local Policies >> Security Options >> "Network access: Restrict clients allowed to make remote calls to SAM".
Select "Edit Security" to configure the "Security descriptor:".

Add "Administrators" in "Group or user names:" if it is not already listed (this is the default).

Select "Administrators" in "Group or user names:".

Select "Allow" for "Remote Access" in "Permissions for "Administrators".

Click "OK".

The "Security descriptor:" must be populated with "O:BAG:BAD:(A;;RC;;;BA) for the policy to be enforced.