Title

Application add-ins must be signed by Trusted Publisher. (Cat II impact)

Discussion

Office 2010 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

The policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2010 -> Excel Options -> Security -> Trust Center “Require that application add-ins are signed by Trusted Publisher” must be set to “Enabled". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\14.0\excel\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 Excel 2010 -> Excel Options -> Security -> Trust Center “Require that application add-ins are signed by Trusted Publisher” to “Enabled".

Additional Identifiers

Rule ID: SV-33850r1_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.