Check: O365-OU-000026
Microsoft Office 365 ProPlus STIG:
O365-OU-000026
(in versions v2 r12 through v1 r2)
Title
When an untrusted program attempts to send e-mail programmatically using the Outlook object model, Outlook must automatically deny it. (Cat II impact)
Discussion
This policy setting controls what happens when an untrusted program attempts to send e-mail programmatically using the Outlook object model. If you enable this policy setting, you can choose from four different options when an untrusted program attempts to send e-mail programmatically using the Outlook object model: - Prompt user - The user will be prompted to approve every access attempt. - Automatically approve - Outlook will automatically grant programmatic access requests from any program. This option can create a significant vulnerability, and is not recommended. - Automatically deny - Outlook will automatically deny programmatic access requests from any program. - Prompt user based on computer security. Outlook will only prompt users when antivirus software is out of date or not running. Important: This policy setting only applies if the "Outlook Security Mode" policy setting under "Microsoft Outlook 2016\Security\Security Form Settings" is configured to "Use Outlook Security Group Policy". If you disable or do not configure this policy setting, when an untrusted application attempts to send mail programmatically, Outlook relies on the setting configured in the ''Programmatic Access'' section of the Trust Center.
Check Content
Verify the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Security >> Security Form Settings >> Programmatic Security >> Configure Outlook object model prompt when sending mail is set to "Enabled (Automatically Deny)". Use the Windows Registry to navigate to the following key: HKCU\software\policies\microsoft\office\16.0\outlook\security If the value for promptoomsend is set to REG_DWORD = 0, this is not a finding.
Fix Text
Set the policy value for User Configuration >> Administrative Templates >> Microsoft Outlook 2016 >> Security >> Security Form Settings >> Programmatic Security >> Configure Outlook object model prompt when sending mail to "Enabled (Automatically Deny)".
Additional Identifiers
Rule ID: SV-223371r879859_rule
Vulnerability ID: V-223371
Group Title: SRG-APP-000488
Expert Comments
CCIs
Number | Definition |
---|---|
CCI-002460 |
The information system enforces organization-defined actions prior to executing mobile code. |
Controls
Number | Title |
---|---|
SC-18 (4) |
Prevent Automatic Execution |