Details
Custom actions add functionality to Outlook that can be triggered as part of a rule. Among other possible features, custom actions can be created that reply to messages in ways that circumvent the Outlook model’s programmatic send protections.
By default, when Outlook or another program initiates a custom action using the Outlook object model, users are prompted to allow or reject the action. If this configuration is changed, malicious code can use the Outlook object model to compromise sensitive information or otherwise cause data and computing resources to be at risk.
Solution
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2013 -> Security -> Security Form Settings -> Custom Form Security ‘Set Outlook object model Custom Actions execution prompt’ to ‘Enabled (Automatically Deny)’.
Supportive Information
The following resource is also helpful.
This security hardening control applies to the following category of controls within NIST 800-53: System and Communications Protection.This control applies to the following type of system Windows.
References
- 800-53|SC-18(4)
- CAT|II
- CCI|CCI-002460
- Rule-ID|SV-53994r1_rule
- STIG-ID|DTOO247
- Vuln-ID|V-17802