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Re: [websec] Content sniffing

Adam Barth <ietf@adambarth.com> Mon, 09 July 2012 21:05 UTC

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From: Adam Barth <ietf@adambarth.com>
Date: Mon, 09 Jul 2012 14:05:26 -0700
Message-ID: <CAJE5ia-qAyM1v9JrKJaO6ORi48oVFfk9x13Pw48M8SnB746D9g@mail.gmail.com>
To: "Richard L. Barnes" <rbarnes@bbn.com>
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Subject: Re: [websec] Content sniffing
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Why is this sniffing gone awry?  Nothing bad seems to have happened in
this example.

Adam


On Mon, Jul 9, 2012 at 1:55 PM, Richard L. Barnes <rbarnes@bbn.com> wrote:
> Related to draft-ietf-websec-mime-sniff, an example of sniffing gone awry:
> <http://lcamtuf.coredump.cx/squirrel/>
>
> It's a valid JPEG image that contains and HTML snippet in a comment segment.  As a result, when a browser loads the URL expecting an image, it renders the image content, and when it expects HTML, it skips the binary junk at the top and renders the HTML [*]. (In both cases, the server reports Content-Type text/html.)   What's even more startling is that Chrome helpfully adds the binary junk at the top as the first child of the <body> element in the parsed DOM!
>
> --Richard
>
>
> [*] At least in Chrome 20.0.1132.47
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