Trust Bar Notifications for unsigned application add-ins must be blocked.

From Microsoft Word 2013 STIG

Part of DTOO131 - Trust Bar Notifications

SV-53566r1_rule Trust Bar Notifications for unsigned application add-ins must be blocked.

Vulnerability discussion

If an application is configured to require all add-ins to be signed by a trusted publisher, any unsigned add-ins the application loads will be disabled and the application will display the Trust Bar at the top of the active window. The Trust Bar contains a message informing users about the unsigned add-in. If a user is allowed to make the determination to allow an unsigned add-in, it increases the risk of malicious code being introduced onto the user's computer or the network.

Check content

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Word 2013 -> Word Options -> Security -> Trust Center "Disable Trust Bar Notification for unsigned application add-ins and block them" is set to "Enabled". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\15.0\word\security Criteria: If the value NoTBPromptUnsignedAddin is REG_DWORD = 1, this is not a finding.

Fix text

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Word 2013 -> Word Options -> Security -> Trust Center "Disable Trust Bar Notification for unsigned application add-ins and block them" to "Enabled".

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