Bypass Google Open Redirect Filter Based on Googleads.g.doubleclick.net <http://googleads.g.doubleclick.net/> -- Google Covert Redirect Vulnerability Based on Googleads.g.doubleclick.net <http://googleads.g.doubleclick.net/>
The vulnerability exists at "Logout?" page with "&continue" parameter, i.e. https://www.google.com/accounts/Logout?service=writely&continue=https://googleads.g.doubleclick.net The vulnerability can be attacked without user login. Tests were performed on Firefox (26.0) in Ubuntu (12.04) and IE (9.0.15) in Windows 7. (1) When a user is redirected from Google to another site, Google will check whether the redirected URL belongs to domains in Google's whitelist (The whitelist usually contains websites belong to Google), e.g. docs.google.com googleads.g.doubleclick.net If this is true, the redirection will be allowed. However, if the URLs in a redirected domain have open URL redirection vulnerabilities themselves, a user could be redirected from Google to a vulnerable URL in that domain first and later be redirected from this vulnerable site to a malicious site. This is as if being redirected from Google directly. One of the vulnerable domain is, googleads.g.doubleclick.net (Google's Ad System) (2) Use one webpage for the following tests. The webpage address is " http://www.inzeed.com/kaleidoscope";. We can suppose that this webpage is malicious. Vulnerable URL: https://www.google.com/accounts/Logout?service=writely&continue=https://google.com/ POC: https://www.google.com/accounts/Logout?service=wise&continue=http%3A%2F%2Fgoogleads.g.doubleclick.net%2Faclk%3Fsa%3DL%26ai%3DCtHoIVxn3UvjLOYGKiAeelIHIBfLQnccEAAAQASAAUNTx5Pf4_____wFgvwWCARdjYS1wdWItMDQ2NjU4MjEwOTU2NjUzMsgBBOACAKgDAaoE5AFP0NHr5cHwFmWgKNs6HNTPVk7TWSV-CDHX83dKdGSWJ2ADoZNIxUHZwjAODRyDY_7nVtpuqSLOTef4xzVxDQ2U22MNbGak33Ur7i2jDB8LdYt9TbC3ifsXmklY5jl3Zpq4_lP7wagVfjt0--tNPPGTR96NGbxgPvfHMq9ZsTXpjhc_lPlnyGjlWzF8yn437iaxhGRwYLt_CymifLO2YaJPkCm9nLpONtUM-mstUSpKQrP2VjjaZkbDtuK0naLLBV37aYEY4TzWQi8fQGN47z4XgpinBCna91zQayZjn2wxccDCl0zgBAGgBhU%26num%3D0%26sig%3DAOD64_3Qi4qG3CRVHRI5AHSkSGuL7HJqSA%26client%3Dca-pub-0466582109566532%26adurl%3Dhttp%3A%2F%2Fwww.inzeed.com%2Fkaleidoscope POC Video: https://www.youtube.com/watch?v=btuSq89khcQ&feature=youtu.be Reporter: Wang Jing, Mathematics, Nanyang Technological University http://www.tetraph.com/wangjing More Details: http://computerobsess.blogspot.com/2014/11/google-covert-redirect-vulnerability.html _______________________________________________ Sent through the Full Disclosure mailing list http://nmap.org/mailman/listinfo/fulldisclosure Web Archives & RSS: http://seclists.org/fulldisclosure/
