2.5.14.3.3.3 Ensure 'Configure Outlook object model prompt When accessing the Formula property of a UserProperty object' is set to 'Enabled: Automatically Deny'

Information

This policy setting controls what happens when a user designs a custom form in Outlook and attempts to bind an Address Information field to a combination or formula custom field. 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.

Rationale:

A custom form in Outlook could be used to gain access to sensitive data and potentially change or exfiltrate that data.

Impact:

Users will not be able to controls what happens when a custom form in Outlook is created and will not be able to bind an Address Information field to a combination or formula custom field.

Important: For this setting to apply, the Outlook Security Mode setting must be enabled in User Configuration\Administrative Templates\Microsoft Outlook 2016\Security\Security with Use Outlook Security Group Policy selected, as set in this benchmark in Section 2.5.14.3.

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default is to prompt users based on computer security, which is the equivalent of the Only when antivirus software is out of date or not running option in the Trust Center, and the user experience is not affected.

Solution

To establish the recommended configuration via GP, set the following UI path to Enabled: Automatically Deny:

User Configuration\Administrative Templates\Microsoft Outlook 2016\Security\Security Form Settings\Programmatic Security\Configure Outlook object model prompt When accessing the Formula property of a UserProperty object

Default Value:

Disabled. (When a user tries to bind an address information field to a combination or formula custom field in a custom form, Outlook relies on the setting configured in the Programmatic Access section of the Trust Center.)

Additional Information:

By default, when a user tries to bind an address information field to a combination or formula custom field in a custom form, Outlook relies on the setting configured in the Programmatic Access section of the Trust Center. This setting determines whether Outlook will warn users about programmatic access attempts:

Only when antivirus software is out of date or not running (the default setting)

Every time

Not at all

If the 'Not at all' option is selected, Outlook will silently grant programmatic access to any program that requests it, which could allow a malicious program to gain access to sensitive information.

See Also

https://workbench.cisecurity.org/benchmarks/12129

Item Details

Category: CONFIGURATION MANAGEMENT, SYSTEM AND COMMUNICATIONS PROTECTION

References: 800-53|CM-10, 800-53|CM-11, 800-53|SC-18

Plugin: Windows

Control ID: 6766e1f11a2bf79baac69fe0280c8f896185ba2cfd231ddb28044b56219b4e78