Add-ins to Office applications must be signed by a Trusted Publisher.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-26589	DTOO127	SV-53682r1_rule	ECSC-1	Medium

Description
Office 2013 applications do not, by default, 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.

STIG	Date
Microsoft Excel 2013 STIG	2015-06-18

Details

Check Text ( C-47805r1_chk )
Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2013 -> Excel 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\excel\security Criteria: If the value RequireAddinSig is REG_DWORD = 1, this is not a finding.

Check Text ( C-47805r1_chk )

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2013 -> Excel 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\excel\security

Criteria: If the value RequireAddinSig is REG_DWORD = 1, this is not a finding.

Fix Text (F-46607r1_fix)
Set the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2013 -> Excel Options -> Security -> Trust Center "Require that application add-ins are signed by Trusted Publisher" to "Enabled".