Monday, July 13, 2009 MoTB #13: Reflected XSS in Brightkite What is Brightkite "Brightkite is a location-based social network. In real time you can see where your friends are and what they're up to. Depending on your privacy settings you can also meet others nearby." (Brightkite home page) Twitter effect Brightkite can be used to send new tweets and reply to other Twitter users. Brightkite is using Username/Password authentication in order to utilize the Twitter API. Popularity rate 16th place in the most used twitter clients, according to “TwitStats” Vulnerability: Reflected Cross-Site in the "Person not found" page. Status: Patched. Details: The Brightkite "Person not found" page did not encode HTML entities in the people query variable, which could have allowed the injection of scripts. This vulnerability could have been used by an attacker to send tweets on behalf of its victims. Proof-of-Concept: http://brightkite.com/people/zxxx%22%3E%3Cbody%20onload=%22alert(%27xss%27)%22%3E Vendor response rate Vulnerability was fixed 1 hour after it has been reported.