Message formats must be set to use SMime.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-71227	DTOO260	SV-85851r1_rule		Medium

Description
Email typically travels over open networks and is passed from server to server. Messages are therefore vulnerable to interception, and attackers might read or alter their contents. It is therefore important to have a mechanism for signing messages and providing end-to-end encryption. Outlook supports three formats for encrypting and signing messages: S/MIME, Exchange, and Fortezza. By default, Outlook only uses S/MIME to encrypt and sign messages. When an organization has policies that mandate the use of specific encryption formats, allowing users to choose freely between these formats could cause them to violate such policies.

Description

Email typically travels over open networks and is passed from server to server. Messages are therefore vulnerable to interception, and attackers might read or alter their contents. It is therefore important to have a mechanism for signing messages and providing end-to-end encryption. Outlook supports three formats for encrypting and signing messages: S/MIME, Exchange, and Fortezza. By default, Outlook only uses S/MIME to encrypt and sign messages. When an organization has policies that mandate the use of specific encryption formats, allowing users to choose freely between these formats could cause them to violate such policies.

STIG	Date
Microsoft Outlook 2016 STIG	2016-12-02

Details

Check Text ( None )
None

Fix Text (F-46893r1_fix)
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2016 -> Security -> Cryptography "Message Formats" to "Enabled (S\MIME)".