Users must not be allowed to ignore Windows Defender SmartScreen filter warnings for unverified files in Microsoft Edge.

From Windows 10 Security Technical Implementation Guide

Associated with: CCI-000366

SV-78191r4_rule Users must not be allowed to ignore Windows Defender SmartScreen filter warnings for unverified files in Microsoft Edge.

Vulnerability discussion

The Windows Defender SmartScreen filter in Microsoft Edge provides warning messages and blocks potentially malicious websites and file downloads. If users are allowed to ignore warnings from the Windows Defender SmartScreen filter they could still download potentially malicious files.

Check content

If the following registry value does not exist or is not configured as specified, this is a finding. Registry Hive: HKEY_LOCAL_MACHINE Registry Path: \SOFTWARE\Policies\Microsoft\MicrosoftEdge\PhishingFilter\ Value Name: PreventOverrideAppRepUnknown Type: REG_DWORD Value: 0x00000001 (1)

Fix text

Configure the policy value for Computer Configuration >> Administrative Templates >> Windows Components >> Microsoft Edge >> "Prevent bypassing Windows Defender SmartScreen prompts for files" to "Enabled". v1703 of Windows 10 includes duplicate policies for this setting. It can also be configured under Computer Configuration >> Administrative Templates >> Windows Components >> Windows Defender SmartScreen >> Microsoft Edge. v1607 of Windows 10, the policy name is "Prevent bypassing SmartScreen prompts for files". Prior to v1607 of Windows 10, the policy name is "Don't allow SmartScreen Filter warning overrides for unverified files".

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