Re: Blocking high-risk non-secure downloads

Emily – can you give some idea of the list of filetypes that you would thinking of blocking?


From: Emily Stark <>
Date: Tuesday, April 9, 2019 at 11:30 AM
To: WebAppSec WG <>
Cc: Mike West <>, Joe DeBlasio <>, "" <>
Subject: Blocking high-risk non-secure downloads
Resent-From: <>
Resent-Date: Tuesday, April 9, 2019 at 11:29 AM

Hi webappsec friends,

Over in Chrome land, we've been considering how to drive down non-secure downloads, particularly high-risk ones like executables. I wanted to see if other browsers would be interested in joining us on this adventure.

We want to achieve the right balance between compatibility/user-disruption and security improvements, so we will likely start by treating certain high-risk downloads initiated from secure contexts as active mixed content and block them. We're still finalizing our metrics before we can share them publicly, but right now it's looking like it will be feasible to block a set of high-risk filetypes (executables and archives as determined by the Content-Type header or sniffed mime-type). We will likely focus on protecting desktop users because Android and Safe Browsing already provide protection<> against malicious APKs.

We're not planning to focus on non-secure downloads initiated from non-secure contexts at the moment, because users at least see the "Not Secure" omnibox badge on those pages.

Feedback welcome!

Received on Tuesday, 9 April 2019 19:21:27 UTC