Title

The Remote Desktop Session Host must require secure Remote Procedure Call (RPC) communications. (Cat II impact)

Discussion

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.

Check Content

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 Text

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".

Additional Identifiers

Rule ID: SV-224947r991554_rule

Vulnerability ID: V-224947

Group Title: SRG-OS-000250-GPOS-00093

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.