Re: [cors] Additional Comments on 17 March 2009 cors draft

So the issue is not confidentiality, it is inappropriate script  
execution. Got it.

Thanks Anne

regards, Frederick

Frederick Hirsch
Nokia



On Jul 1, 2009, at 5:34 AM, ext Anne van Kesteren wrote:

> I might not have time to address your larger set of questions before I
> leave on vacation tomorrow, but I thought I could at least answer  
> this one.
>
> On Tue, 30 Jun 2009 17:38:20 +0200, Frederick Hirsch
> <Frederick.Hirsch@nokia.com> wrote:
>> One additional question regarding a cross-site get (using browser  
>> here
>> for simplicity of terms) (for example, see [1])
>>
>> Is it true that
>>
>> 1. the GET results in the content being returned on the wire with a
>> Access-Control-Allow-Origin header
>> 2. the browser then checks this header and enforces policy
>> 3. if policy disallows then the browser does not allow the content  
>> to be
>> used.
>
> Yes, this is correct.
>
>
>> In any case, doesn't this open an attack to get the content by  
>> sniffing
>> the wire for the response content, regardless of the header?
>
> If that is a viable attack scenario such servers are already exposed  
> due
> to e.g. cross-origin <img> or <iframe> loading which already works  
> today.
> Or e.g. by simply setting window.location to the address from which  
> you
> want to sniff the response.
>
> All the header is effectively protecting is exposing the "raw"  
> contents of
> a cross-origin resource to script.
>
>
>> [1] http://arunranga.com/examples/access-control/SimpleXSInvocation.txt
>
>
> -- 
> Anne van Kesteren
> http://annevankesteren.nl/

Received on Wednesday, 1 July 2009 13:24:31 UTC