Re: [http-state] Security considerations overview

Maciej Stachowiak <mjs@apple.com> Wed, 03 March 2010 00:11 UTC

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From: Maciej Stachowiak <mjs@apple.com>
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Date: Tue, 02 Mar 2010 16:11:55 -0800
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To: Adam Barth <ietf@adambarth.com>
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Subject: Re: [http-state] Security considerations overview
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On Mar 2, 2010, at 3:39 PM, Adam Barth wrote:

>
> The issue is quite simple:
>
> 1) In an HTTPS response, the example.com server responds with
> "Set-Cookie: foo=bar".  By default (i.e., without the optional Secure
> attribute), this cookie does not have the secure-only-flag set.
> 2) The user agent makes a single HTTP request.
> 3) The network attacker spoofs an HTTP response that contains an HTTP
> redirect to http://example.com/.
> 4) The user agent follows the redirect and sends the cookie foo in the
> clear, where it can be observed by the attacker.

Sounds like attacker can violate the integrity, as well as  
confidentiality, of non-Secure cookies this way (i.e. they could spoof  
the non-SSL response and set the cookie to the value of their choice.)

Can this type of attack also affect the integrity of Secure cookies,  
or is there something to prevent them from being overwritten from non- 
SSL?

Regards,
Maciej