Users must be prevented from creating new trusted locations in the Trust Center.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-223293	O365-CO-000010	SV-223293r508019_rule		Medium

Description
This policy setting controls whether trusted locations can be defined by users, the Office Customization Tool (OCT), and Group Policy, or if they must be defined by Group Policy alone. If you enable this policy setting, users can specify any location as a trusted location, and a computer can have a combination of user-created, OCT-created, and Group Policy-created trusted locations. If you disable this policy setting, all trusted locations that are not created by Group Policy are disabled and users cannot create new trusted locations in the Trust Center. If you do not configure this policy setting, the behavior is the equivalent of setting the policy to Enabled. Note: InfoPath and Outlook do not recognize trusted locations, and therefore are unaffected by this policy setting.

Description

This policy setting controls whether trusted locations can be defined by users, the Office Customization Tool (OCT), and Group Policy, or if they must be defined by Group Policy alone. If you enable this policy setting, users can specify any location as a trusted location, and a computer can have a combination of user-created, OCT-created, and Group Policy-created trusted locations. If you disable this policy setting, all trusted locations that are not created by Group Policy are disabled and users cannot create new trusted locations in the Trust Center. If you do not configure this policy setting, the behavior is the equivalent of setting the policy to Enabled. Note: InfoPath and Outlook do not recognize trusted locations, and therefore are unaffected by this policy setting.

STIG	Date
Microsoft Office 365 ProPlus Security Technical Implementation Guide	2020-09-11

Details

Check Text ( C-24966r442098_chk )
Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Office 2016\Security Settings\Trust Center >> Allow mix of policy and user locations is set to "Disabled". Use the Windows Registry Editor to navigate to the following key: HKCU\software\policies\microsoft\office\16.0\common\security\trusted locations If the value for allow user locations is set to REG_DWORD = 0, this is not a finding.

Check Text ( C-24966r442098_chk )

Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Office 2016\Security Settings\Trust Center >> Allow mix of policy and user locations is set to "Disabled".

Use the Windows Registry Editor to navigate to the following key:

HKCU\software\policies\microsoft\office\16.0\common\security\trusted locations

If the value for allow user locations is set to REG_DWORD = 0, this is not a finding.

Fix Text (F-24954r442099_fix)
Set the policy value for User Configuration >> Administrative Templates >> Microsoft Office 2016 >> Security Settings >> Trust Center >> Allow mix of policy and user locations to "Disabled".