# Exploit Title: Chrome 18 anti-XSS bypass # Date: 2012-05-31 # Author: k3170makan # Vendor or Software Link: [download link if available] # Version: 18.0.1025.162 # Category:: local # Google dork: N/A # Tested on: Ubuntu 10.04 # Demo site: N/A Chrome 18---and possibly 19--- versions anti-XSS filter or XSSAuditor as its called does not pick up certain XSS vectors. Its possible to by pass the XSSAuditor by fooling it into believing that the javascript you inject is commented out. To do this you need to use both in line and multiline comment tags after one another in the injection: Code Snippet: else if (startsMultiLineCommentAt(string, startPosition)) { if ((foundPosition = string.find("*/", startPosition)) != notFound) startPosition = foundPosition + 2; /*<--- skips 2 chars here*/ Because the Auditor skips two chars you can fool it by add another slash to an inline incomment that succeeds a multiline comment e.g '/*//'+'/' So you need to make sure that in your injection---before any actual javascript syntax---you include "/*///" and make sure to close the comment as well Some examples would be: <script>/*///*/alert(1);</script> #it will pick up the multiline comment here and skip to the next 2 chars, which will again be comments, so the check will pass leaving the javascript alone! <script>/*///////*/alert(1);</script> you can add whatever chars you want to the vector after the '/*///' part as long as you close the comment obviously. Chrome Issue track ---> http://code.google.com/p/chromium/issues/detail?id=130594 gr33ts Telspace Systems ;) site:k3170makan.blogspot.com