Awesome TLS – Evading WAFs With Advanced Burp Suite Extension

This extension hijacks Burp’s HTTP and TLS stack, allowing you to spoof any browser TLS fingerprint (JA3).

It boosts the power of Burp Suite while reducing the likelihood of fingerprinting by various WAFs like CloudFlare, PerimeterX, Akamai, DataDome, etc.

It does this without resorting to hacks, reflection or forked Burp Suite Community code.

All code in this repository only leverages Burp’s official Extender API.

Sponsors

Scrapfly is an enterprise-grade solution providing Web Scraping API that aims to simplify the scraping process by managing everything: real browser rendering, rotating proxies, and fingerprints (TLS, HTTP, browser) to bypass all major anti-bots. Scrapfly also unlocks observability by providing an analytical dashboard and measuring the success rate/block rate in detail.

Scrapfly is a good solution if you are looking for a robust solution to access the website behind WAF for web scraping use cases – We also provide a set of tools to verify your TLS fingerprint and HTTP/2 Fingerprint.

How It Works

Unfortunately Burp’s Extender API is very limited for more advanced use cases like this, so I had to play around with it to make this work.

Once a request comes in, the extension intercepts it and forwards it to a local HTTPS server that started in the background (once the extension loaded).

This server works like a proxy; it forwards the request to the destination, while persisting the original header order and applying a customizable TLS configuration.

Then, the local server forwards the response back to Burp. The response header order is also preserved.

Configuration settings and other necessary information like the destination server address and protocol are sent to the local server per request by a magic header.

This magic header is stripped from the request before it’s forwarded to the destination server, of course.

For more information click here.