Re: Redirect and Origin

On Tue, Jun 9, 2009 at 2:52 PM, Adam Barth<w3c@adambarth.com> wrote:
> On Tue, Jun 9, 2009 at 2:20 PM, Tyler Close<tyler.close@gmail.com> wrote:
>> I had thought CORS, by it's use of Origin, was meant to be a safe
>> replacement for JSON-P.
>
> Can you explain again how the attack works for Origin-header-for-CORS?
>  Keep in mind that the response is delivered to the original
> requester, who should be accurately identified by the Origin header
> (even through redirects).

But the side-effects of the request still happen. The attacker can
cause mutation of server-side state belonging to the victim user.

I believe the scenario in the first email works as described in CORS.
I don't see anything in the CORS redirect steps that changes the
Origin processing from what is described in your I-D.

http://www.w3.org/TR/access-control/#redirect-steps

These documents really need to state that they are only addressing
messaging between mutually trusting sites.

--Tyler

-- 
"Waterken News: Capability security on the Web"
http://waterken.sourceforge.net/recent.html

Received on Tuesday, 9 June 2009 22:06:34 UTC