Information
This policy setting controls what happens when an untrusted program attempts to gain access to an Address Book using the Outlook object model. The Outlook object model includes entry points to access Outlook data, save data to specified locations, and send emails.
When the option Automatically deny is selected, Outlook will automatically deny programmatic access requests from any program.
The recommended state for this setting is: Enabled: Automatically Deny
If an untrusted application accesses the address book, the application could gain access to sensitive data and potentially change or exfiltrate that data.
Solution
To establish the recommended state via configuration profiles, set the following Settings Catalog path to Enabled: Automatically Deny :
Microsoft Outlook 2016\Security\Security Form Settings\Outlook Security Mode > Configure Outlook object model prompt when accessing an address book
Important: For this setting to apply, the
Outlook Security Mode
setting must be enabled in
Microsoft Outlook 2016\Security\Security Form Settings
with Use Outlook Security Group Policy selected, as set in this benchmark.
Impact:
Untrusted programs will not be able to gain access to the Address Book using the Outlook object model.
If Group Policy security settings are used for Outlook, the Programmatic Access section of the Trust Center is not used. In this situation, the default is to prompt users based on computer security, which is the equivalent of the Only when antivirus software is out of date or not running option in the Trust Center, and the user experience is not affected.