Windows Server 2019 Remote Desktop Services must require secure Remote Procedure Call (RPC) communications.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-205636	SRG-OS-000033-GPOS-00014	WN19-CC-000370	SV-205636r958408_rule	2025-02-25	3

Description
Allowing unsecure RPC communication exposes the system to man-in-the-middle attacks and data disclosure attacks. A man-in-the-middle attack occurs when an intruder captures packets between a client and server and modifies them before allowing the packets to be exchanged. Usually the attacker will modify the information in the packets in an attempt to cause either the client or server to reveal sensitive information. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000250-GPOS-00093

Description

Allowing unsecure RPC communication exposes the system to man-in-the-middle attacks and data disclosure attacks. A man-in-the-middle attack occurs when an intruder captures packets between a client and server and modifies them before allowing the packets to be exchanged. Usually the attacker will modify the information in the packets in an attempt to cause either the client or server to reveal sensitive information. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000250-GPOS-00093

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: \SOFTWARE\Policies\Microsoft\Windows NT\Terminal Services\ Value Name: fEncryptRPCTraffic Type: REG_DWORD Value: 0x00000001 (1)

✔️ Fix
Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Remote Desktop Services >> Remote Desktop Session Host >> Security >> "Require secure RPC communication" to "Enabled".