UCF STIG Viewer Logo

Outlook must use remote procedure call (RPC) encryption to communicate with Microsoft Exchange servers.


Overview

Finding ID Version Rule ID IA Controls Severity
V-223347 O365-OU-000002 SV-223347r508019_rule Medium
Description
This policy setting controls whether Outlook uses remote procedure call (RPC) encryption to communicate with Microsoft Exchange servers. If you enable this policy setting, Outlook uses RPC encryption when communicating with an Exchange server. Note: RPC encryption only encrypts the data from the Outlook client computer to the Exchange server. It does not encrypt the messages themselves as they traverse the Internet. If you disable or do not configure this policy setting, RPC encryption is still used by default. This setting allows you to override the corresponding per-profile setting.
STIG Date
Microsoft Office 365 ProPlus Security Technical Implementation Guide 2022-06-17

Details

Check Text ( C-25020r442260_chk )
Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Account Settings >> Exchange >> Enable RPC encryption is set to "Enabled".

Use the Windows Registry to navigate to the following key:

HKCU\software\policies\microsoft\office\16.0\outlook\rpc

If the value for enablerpcencryption is set to REG_DWORD = 1, this is not a finding.
Fix Text (F-25008r442261_fix)
Set the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Account Settings >> Exchange >> Enable RPC encryption to "Enabled".