Changing document.domain to completely other domain

javascript

Solution

Check out : developer.mozilla.org/same-origin-policy

Here is an excerpt from the site:

There is one exception to the same origin rule. A script can set the value of document.domain to a suffix of the current domain. If it does so, the shorter domain is used for subsequent origin checks. For example, assume a script in the document at http://store.company.com/dir/other.html executes the following statement:

document.domain = "company.com";

After that statement executes, the page would pass the origin check with http://company.com/dir/page.html. However, by the same reasoning, company.com could not set document.domain to othercompany.com.

Problem

I'm trying to prove that changing document.domain can be used only for cross scripting on the same upper level domain. For example if i will try to change document.domain to "google.com" on page which is located on www.test.com I will get a security exception in FF. Does anybody know where to locate an official proof of that?

Original source