Blocking as default file block opening behavior must be enforced.

From Microsoft Excel 2013 STIG

Part of DTOO110 - Set default file block behavior

Associated with: CCI-001662

SV-53617r1_rule Blocking as default file block opening behavior must be enforced.

Vulnerability discussion

Users can open, view, or edit a large number of file types in Office 2013. 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

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2013 -> Excel Options -> Security -> Trust Center -> File Block Settings "Set default file block behavior" is set to "Enabled: Blocked files are not opened". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\15.0\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 2013 -> Excel Options -> Security -> Trust Center -> File Block Settings "Set default file block behavior" to "Enabled: Blocked files are not opened".

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