Title

Blocking as default file block opening behavior must be enforced. (Cat II impact)

Discussion

Users can open, view, or edit a large number of file types in Excel 2010. Some file types are safer than others, as some could allow malicious code to become active on user computers or the network. For this reason, disabling or not configuring this setting could allow malicious code to 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 -> File Block Settings “Set default file block behavior” must be “Enabled: Blocked files are not opened". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\14.0\excel\security\fileblock Criteria: If the value OpenInProtectedView is REG_DWORD = 0, this is not a finding.

Fix Text

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2010 -> Excel Options -> Security -> Trust Center -> File Block Settings “Set default file block behavior” to “Enabled: Blocked files are not opened".

Additional Identifiers

Rule ID: SV-33872r1_rule

Vulnerability ID: V-26612

Group Title: DTOO110 - Set default file block behavior

Expert Comments

CCIs tied to check.

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