XSS

A quick overview of cross site scripting

Transcript

1. XSS (Cross Site Scripting)
2. What is it? • Text based attack • Exploits the browser's interpreter, allowing the attacker to run code on the target site
3. What can be done using XSS? • hijack user sessions • insert content • redirect users • hijack the user’s browser using malware
4. Who can do these attacks? • Anyone that can send data to the system • Anyone that can craft a url and put it in front of other people
5. Types of XSS
6. Stored • User input is stored on the server and rendered to any user that visits the page • Eg. User reviews, comments, profiles
7. Reflected • User input is returned by the web application and rendered without being sanitized • Eg. Search results
8. DOM Based XSS • The response doesn't contain the exploit payload • Some client side code reads the malicious data from the URL or DOM and executes it
9. Demo! Great resource from Google
10. Example attacks • Samy MySpace Worm • Spread through 1 million users in 20 hours • StrongWebmail CEO email hacked • XSS Worm Examples
11. Prevention • Properly escape untrusted data • Input validation can help, but isn't a full solution • Use sanitization libraries
12. FIN