Bypassing Modern WAF's XSS Filters - Cheat Sheet

Last month i was asked by my university teacher "Sir Asim Ali" to write a paper on any topic related to "Computer Architecture" as a semester project. I was particularly interested in writing security related stuff, let it be related to computer architecture, networks etc. However i found that lots of work has already been done on the architecture level security. Therefore, i convinced my teacher that i'll be writing on "Bypassing Modern Web Application Firewall's" as some of you might know that most of my research is related to client side vulnerabilities and bypassing WAF's.


In my day to day job as a penetration tester, it's very often that i encounter a web application firewall/filter that looks for malicious traffic inside the http request and filters it out, some of them are easy to break and some of them are very hard. However, in one or another context all the WAF's i have encountered are bypassable at some point.

Rsnake's XSS cheat sheet was one of the best resources available for bypassing WAF's, however overtime as browsers got updated lots of the vectors didn't work on the newer browser. Therefore there was a need to create a new Cheat Sheet. Over time i have developed my own methodology for bypassing WAF's and that's what i have written the paper on. The paper talks specifically about bypassing XSS filters, as for SQLi, RCE etc. I thought to write a different paper as the techniques differ in many cases.

  Modern Web Application Firewalls Fingerprinting and Bypassing XSS Filters