Re: [http-state] Seeking feedback on Security Considerations

"Yngve N. Pettersen (Developer Opera Software ASA)" <yngve@opera.com> Sat, 13 February 2010 10:48 UTC

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To: "Adam Barth" <ietf@adambarth.com>, http-state <http-state@ietf.org>
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Date: Sat, 13 Feb 2010 11:48:56 +0100
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From: "Yngve N. Pettersen (Developer Opera Software ASA)" <yngve@opera.com>
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Subject: Re: [http-state] Seeking feedback on Security Considerations
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On Sat, 13 Feb 2010 09:01:08 +0100, Adam Barth <ietf@adambarth.com> wrote:

> The new draft that I've uploaded
> <http://www.ietf.org/id/draft-ietf-httpstate-cookie-03.txt> contains
> an updated and expanded Security Considerations section.  I've been
> circulating this section among security experts for feedback.  If you
> have some feedback on this section, I'd like to encourage you to let
> me know at this time.
>
> I've reproduced the Security Considerations section below for your  
> convenience.
>
> Thanks,
> Adam
>
>

> 7.5.  Weak Integrity
>
>    Cookies do not provide integrity guarantees for sibling domains (and
>    their subdomains).  For example, consider foo.example.com and
>    bar.example.com.  The foo.example.com server can set a cookie with a
>    Domain attribute of ".example.com", and the user agent will include
>    that cookie in HTTP requests to bar.example.com.

A bar.example.com can also overwrite a ".example.com" cookie set by  
foo.example.com. Maybe that should be mentioned?


Another possible issues that maybe should be mentioned is that in shared  
hosting environments where multiple independent services are hosted in the  
same domain or on the same server it is possible for a malicious service  
to interfere with other services by setting cookies for domains and paths  
that will get them sent to other services.

Should the fact that clients also support cookies through HTML meta tags  
and the Javascript document.cookie API be mentioned? The latter could be a  
concern when including external Javascripts directly into a HTML document.

-- 
Sincerely,
Yngve N. Pettersen

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