Excel attachments opened from Outlook must be in Protected View.

From Microsoft Excel 2016 Security Technical Implementation Guide

Associated with: CCI-001170

SV-85655r1_rule Excel attachments opened from Outlook must be in Protected View.

Vulnerability discussion

This policy setting allows you to determine if Excel files in Outlook attachments open in Protected View. If you enable this policy setting, Outlook attachments do not open in Protected View. If you disable or do not configure this policy setting, Outlook attachments open in Protected View.

Check content

Verify the policy value for User Configuration -> Administrative Templates -> Microsoft Excel 2016 -> Excel Options -> Security -> Trust Center -> Protected View "Turn off Protected View for attachments opened from Outlook" is set to "Disabled". 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 DisableAttachmentsInPV 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 "Turn off Protected View for attachments opened from Outlook" to "Disabled".

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