From: Daniel Kahn Gillmor Date: Wed, 28 Jan 2015 03:47:35 +0000 (+1900) Subject: Re: privacy problem: text/html parts pull in network resources X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=cd16edb80ba0a969ed0b8e8d4af50436ff63036a;p=notmuch-archives.git Re: privacy problem: text/html parts pull in network resources --- diff --git a/f3/43f8fc0a4659db367ffc922b7d8526480d82f1 b/f3/43f8fc0a4659db367ffc922b7d8526480d82f1 new file mode 100644 index 000000000..3aec49375 --- /dev/null +++ b/f3/43f8fc0a4659db367ffc922b7d8526480d82f1 @@ -0,0 +1,83 @@ +Return-Path: +X-Original-To: notmuch@notmuchmail.org +Delivered-To: notmuch@notmuchmail.org +Received: from localhost (localhost [127.0.0.1]) + by olra.theworths.org (Postfix) with ESMTP id F035D431FC9 + for ; Tue, 27 Jan 2015 19:47:33 -0800 (PST) +X-Virus-Scanned: Debian amavisd-new at olra.theworths.org +X-Spam-Flag: NO +X-Spam-Score: 2.438 +X-Spam-Level: ** +X-Spam-Status: No, score=2.438 tagged_above=-999 required=5 + tests=[DNS_FROM_AHBL_RHSBL=2.438] autolearn=disabled +Received: from olra.theworths.org ([127.0.0.1]) + by localhost (olra.theworths.org [127.0.0.1]) (amavisd-new, port 10024) + with ESMTP id eG74-x1mUycZ for ; + Tue, 27 Jan 2015 19:47:30 -0800 (PST) +Received: from che.mayfirst.org (che.mayfirst.org [209.234.253.108]) + by olra.theworths.org (Postfix) with ESMTP id A8741431FAF + for ; Tue, 27 Jan 2015 19:47:30 -0800 (PST) +Received: from fifthhorseman.net (ool-6c3a0662.static.optonline.net + [108.58.6.98]) + by che.mayfirst.org (Postfix) with ESMTPSA id 73BF4F984; + Tue, 27 Jan 2015 22:47:27 -0500 (EST) +Received: by fifthhorseman.net (Postfix, from userid 1000) + id 20B81201F8; Tue, 27 Jan 2015 22:47:35 -0500 (EST) +From: Daniel Kahn Gillmor +To: David Bremner , + notmuch mailing list +Subject: Re: privacy problem: text/html parts pull in network resources +In-Reply-To: <87fvay3g0g.fsf@maritornes.cs.unb.ca> +References: <87ppa7q25w.fsf@alice.fifthhorseman.net> + <87fvay3g0g.fsf@maritornes.cs.unb.ca> +User-Agent: Notmuch/0.18.2 (http://notmuchmail.org) Emacs/24.4.1 + (x86_64-pc-linux-gnu) +Date: Tue, 27 Jan 2015 22:47:35 -0500 +Message-ID: <871tmfin1k.fsf@alice.fifthhorseman.net> +MIME-Version: 1.0 +Content-Type: text/plain +X-BeenThere: notmuch@notmuchmail.org +X-Mailman-Version: 2.1.13 +Precedence: list +List-Id: "Use and development of the notmuch mail system." + +List-Unsubscribe: , + +List-Archive: +List-Post: +List-Help: +List-Subscribe: , + +X-List-Received-Date: Wed, 28 Jan 2015 03:47:34 -0000 + +On Sun 2015-01-25 12:51:43 -0500, David Bremner wrote: +> Daniel Kahn Gillmor writes: +> +>> If i send a message with a text/html part (either it's only text/html, +>> or all parts are rendered, or it's multipart/alternative with only a +>> text/html subpart) and that HTML has > src="http://example.org/test.png"/> in it, then notmuch will make a +>> network request for that image. +>> +>> This is a privacy disaster, because it enables an e-mail sender to use +>> "web bugs" to tell when a given notmuch user has opened their e-mail. +> +> I've just pushed Austin's shr related series to master, so this problem +> should be fixed as of commit b74ed1c. One tradeoff that we should at +> least remark in NEWS, if not actually fix, is that I think there is now +> no way to view such images in notmuch. I don't know offhand what other +> html renderers will do. + +thanks for this, David and Austin! + +Other html-rendering mail clients that are privacy-conscious will often +provide a button or mechanism to indicate that some remote resources +were requested by the page but weren't fetched (e.g. a button saying +something like [Load Remote Images...]). I have no idea who actually +clicks on those buttons (or why), though, and even if we wanted them, +we'd only want to add a button on an image that actually had remote +network resources to load, and i don't know how we'd get that +information propagated back up the rendering stack to make such a +display decision. So i'm fine with leaving it this way for now. + + --dkg