Title

Object Model Prompt behavior for Meeting and Task Responses must be configured. (Cat II impact)

Discussion

If an untrusted application programmatically responds to tasks or meeting requests, that application could impersonate a user response to the tasks or meeting requests with false information. By default, when an untrusted application attempts to respond to tasks or meeting requests 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determines whether Outlook will warn users about programmatic access attempts: • Only when antivirus software is out of date or not running (the default setting) • Every time • Not at all If the "Not at all" option is selected, Outlook will silently grant programmatic access to any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default is to prompt users based on computer security, which is the equivalent of the "Only when antivirus software is out of date or not running" option in the Trust Center, and the user experience is not affected.

Check Content

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2013 -> Security -> Security Form Settings -> Programmatic Security "Configure Outlook object model prompt when responding to meeting and task requests" is set to "Enabled (Automatically Deny)". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\15.0\outlook\security Criteria: If the value PromptOOMMeetingTaskRequestResponse is REG_DWORD = 0, this is not a finding.

Fix Text

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Outlook 2013 -> Security -> Security Form Settings -> Programmatic Security "Configure Outlook object model prompt when responding to meeting and task requests" to "Enabled (Automatically Deny)".

Additional Identifiers

Rule ID: SV-55912r1_rule

Vulnerability ID: V-17573

Group Title: DTOO252-Object Model Prompt for Meeting Response

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.