Re: Google / GMail bug, all accounts vulnerable

["Kristian Erik Hermansen" <kristian.hermansen () gmail com>]

On Dec 11, 2007 3:01 PM, Aaron Katz <atkatz () gmail com> wrote:
> My strong suspicion is that the original poster simply created a
> JavaScript script in somewhere.google.com, and this JavaScript deleted
> the cookie.  This would work if the session cookie is restricted to
> google.com, which would let any web server in, or content served from
> the google.com domain (or any subdomain).
>
> My note about using NoScript to restrict JavaScript execution to
> mail.google.com reinforces this suspicion.
>
> If my suspicion is correct, then google did two things.  First, google
> appears to allow individuals to create personal domain names in
> google.com, and to place arbitrary content in those domains.  This
> first thing probalby allowed the original poster to place the
> JavaScript in a location where it could access the google.com cookie.
> Second, google apparantly did not restrict the gmail cookie to
> mail.google.com.  This second thing allowed the JavaScript from the
> personal system at somewhere.google.com to access the cookie.
>
>
> Of course, I only did a cursory glance at the source of the webpage,
> so I may be wrong :)  But, we can be reasonably sure it's not
> exploiting a problem in the browser, since the issue appears to be
> cross browser.

Well, let me just say that NoScript will not save you here in my
example.  Try this to see how to really mess with your brain...

* Open Firefox 2.x (delete all cookies/cached objects if you like, etc)
* Check an email in Google
* Visit my PoC code page in a new tab
* Click on the Google tab and try to read an email
* Something went wrong...
* Log back into Google
* Browse around your email, or not, doesn't matter
* Merely click on the tab for my PoC webpage
* Something goes wrong again...

Just clicking a tab in Firefox can mess with your Google account?
Details will be released this Friday and will also include an exploit
for Yahoo as well.  Fair warning...
-- 
Kristian Erik Hermansen
"I have no special talent. I am only passionately curious."

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