2.5.14.3.3.4 Ensure 'Configure Outlook object model prompt when executing Save As' is set to 'Enabled: Automatically Deny'

Information

This policy setting controls what happens when an untrusted program attempts to use the Save As command to programmatically save an item.

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:

If an untrusted application uses the Save As command to programmatically save an item, the application could add malicious data to a user's inbox, a public folder, or an address book.

Impact:

Untrusted programs will not be able to use the Save As command to programmatically save an item.

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default is to prompt users based on computer security, which is the equivalent of the Only when antivirus software is out of date or not running option in the Trust Center, and the user experience is not affected.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

Default Value:

Disabled. (When an untrusted application attempts to use the Save As command, Outlook relies on the setting configured in the Programmatic Access section of the Trust Center.)

Additional Information:

By default, when an untrusted application attempts to access the address book programmatically, 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Only when antivirus software is out of date or not running (the default setting)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.

Note: This described default functionality assumes that you have not followed the recommendation to enable the 'Outlook Security Mode' Group Policy setting to ensure that Outlook security settings are configured by Group Policy. 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.

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: 49ba3bda5f668654c2aac270c620cb2cc8828cbf89d9c951d3b5db2431ad566b