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V-223347

CAT II (Medium)

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

Rule ID

SV-223347r961878_rule

STIG

Microsoft Office 365 ProPlus Security Technical Implementation Guide

Version

V3R5

CCIs

CCI-001967

Discussion

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.

Check Content

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

Set the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Account Settings >> Exchange >> Enable RPC encryption to "Enabled".