Title

Add-ins to Office applications must be signed by a Trusted Publisher. (Cat II impact)

Discussion

Office 2013 applications do not check the digital signature on application add-ins before opening them. Disabling or not configuring this setting may allow an application to load a dangerous add-in. As a result, malicious code could become active on user computers or the network.

Check Content

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Word 2013 -> Word Options -> Security -> Trust Center "Require that application add-ins are signed by Trusted Publisher" 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 RequireAddinSig 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 "Require that application add-ins are signed by Trusted Publisher" to "Enabled".

Additional Identifiers

Rule ID: SV-53564r1_rule

Vulnerability ID: V-26589

Group Title: DTOO127 - Add-ins are signed by Trusted Publisher

Expert Comments

CCIs tied to check.

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