Windows Server 2019 must restrict unauthenticated Remote Procedure Call (RPC) clients from connecting to the RPC server on domain-joined member servers and standalone or nondomain-joined systems.

Severity
Group ID
Group Title
Version
Rule ID
Date
STIG Version
mediumV-205814SRG-OS-000379-GPOS-00164WN19-MS-000040SV-205814r971545_rule2025-02-253
Description
Unauthenticated RPC clients may allow anonymous access to sensitive information. Configuring RPC to restrict unauthenticated RPC clients from connecting to the RPC server will prevent anonymous connections.
ℹ️ Check
This applies to member servers and standalone or nondomain-joined 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: \SOFTWARE\Policies\Microsoft\Windows NT\Rpc\ Value Name: RestrictRemoteClients Type: REG_DWORD Value: 0x00000001 (1)
✔️ Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> System >> Remote Procedure Call >> "Restrict Unauthenticated RPC clients" to "Enabled" with "Authenticated" selected.