Re:Hacking Google for Fun and Profit
by underwater on Thursday December 15, 2011 @12:57AM
(#3355181)
Tokens would not have helped for the first two. They were logic errors; the attacker used Google features in ways they were not expected to.
The first was a GET request, not POST. Images have fairly lax cross domain restrictions. So while the attacking website can't see the image loaded from Google they can detect when the image doesn't load. Google was returning a non-200 response code for images the user can't see.
The second wasn't a traditional XSRF. Instead it was making the victim (unknowningly) edit a shared document created by the attacker. The attacker uses the feature of Google docs that shows all current editors to see the victim's Google account name.
The first was a GET request, not POST. Images have fairly lax cross domain restrictions. So while the attacking website can't see the image loaded from Google they can detect when the image doesn't load. Google was returning a non-200 response code for images the user can't see.
The second wasn't a traditional XSRF. Instead it was making the victim (unknowningly) edit a shared document created by the attacker. The attacker uses the feature of Google docs that shows all current editors to see the victim's Google account name.