Files on local Intranet UNC must be opened in Protected View.

From Microsoft Excel 2016 Security Technical Implementation Guide

Associated with: CCI-001170

SV-86263r1_rule Files on local Intranet UNC must be opened in Protected View.

Vulnerability discussion

This policy setting lets you determine if files on local Intranet UNC file shares open in Protected View. If you enable this policy setting, files on local Intranet UNC file shares open in Protected View if their UNC paths appear to be within the Internet zone. If you disable or do not configure this policy setting, files on Intranet UNC file shares do not open in Protected View if their UNC paths appear to be within the Internet zone.

Check content

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2016 -> Excel Options -> Security -> Trust Center -> Protected View "Open files on local Intranet UNC in Protected View" is set to "Enabled". Procedure: Use the Windows Registry Editor to navigate to the following key: HKCU\Software\Policies\Microsoft\Office\16.0\excel\security\protectedview Criteria: If the value DisableIntranetCheck is REG_DWORD = 0, this is not a finding.

Fix text

Set the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2016 -> Excel Options -> Security -> Trust Center -> Protected View "Open files on local Intranet UNC in Protected View" to "Enabled".

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