[tor-talk] Security issue

Yuri yuri at rawbw.com
Tue Jan 21 08:55:20 UTC 2014


On 01/20/2014 16:25, Gerardus Hendricks wrote:
>
>> With Tor Browser Bundle default settings any web-site can access to
>> local resources by JavaScript and XMLHttpRequest.
>
> Could you please explain why the same-origin policy of Firefox doesn't 
> prevent this? 


Which 'same-origin policy' are you referring to?
I only see security.fileuri.strict_origin_policy in FF, and it only 
applies to the file URIs (as its name says).
Otherwise, cross origin access is allowed, as demoed here 
http://www.leggetter.co.uk/2010/03/12/making-cross-domain-javascript-requests-using-xmlhttprequest-or-xdomainrequest.html

Browsers should not allow cross origin from global URI to local URIs and 
loopback addresses. There are only 3 classes of local IPs + loopback 
address.
I am not able to verify this now. But if browser allows this, this is a 
major security violation.

The danger of such cross-origin access is that the remote site can use 
this to learn something about the local network of the client, which 
should be disallowed.

Yuri


More information about the tor-talk mailing list