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PwnFox - An IDOR Hunter's Best Friend

Maybe I’m a bit late to the game on this one, but I recently discovered PwnFox and it has quickly one of my favorite tools yet.

So, what is PwnFox? To put it simply, it’s a BurpPro extension that works with Firefox. It accomplishes two things. First, it helps containerize up to eight (yes, that’s right… eight!) different sessions within one browser and secondly, it organizes all your proxied traffic in Burp BY COLOR!

I’ll dive a bit more into #2 in a second.

Now, I’m a sucker for manual exploitation. Not because I don’t believe in automation, believe me, I do, but I like to have granular control over what’s going on and PwnFox is a great tool for just that purpose.

Whether you use Firefox or the built-in Chromium browser within Burp, I’m sure there have been at least a few times where you’ve noticed that you have your browser and can also open a new incognito window and run a different session. Usually that’s where Burp stops.

Even if you open another incognito browser, chances are it will pull/share cookies from the other incognito browser, which is certainly annoying.

Enter PwnFox: 

Look at the beautiful interface. Notice the different colors at the top of each tab. PwnFox organizes everything in one window, and each “color” tab has its own containerized session/cookies.

And when you navigate in each tab, you will find that your traffic proxied in Burp, has been color-coded!

So no more going through each request to see which one belongs to which session. Being able to identify the tab/correlated session is huge!

This capability allows you to send a request to repeater and hot-swap cookies much easier… so yes, finding IDORs has become 10 times more efficient.

Not to mention the fact that if you’re testing a web app, now you can test more than two sessions/roles at a time!

Not quite sold on PwnFox? No problem, I will get you there.

Here’s the set-up:

  1. Head to https://addons.mozilla.org/en-US/firefox/addon/pwnfox/ and download the extension for Firefox and install it.
  2. Now head to https://github.com/yeswehack/PwnFox/releases and download the PwnFox.jar file.
  3. In Burp, head to Extender and import the PwnFox.jar file.
  4. Now, in Firefox, turn the proxy on (via the PwnFox icon) and click any of the container “colors”:

And that’s it; you’re done! You should be able to see the color-coded traffic in your Burp proxy history.

Curious how it works?

The container adds an “X-PwnFox-Color” header to each request… this is how Burp knows what color to highlight with each request. Simple, yet brilliant.

There are a few bugs that I’ve noticed:

  • You may need to restart Firefox and Burp for it to work properly
  • Changing the container name may break the colors showing up in Burp. Just leave the default names as is (ex. PwnFox-blue).

And this is just scratching the surface of what PwnFox can do for you. There are other features I still need to explore, such as that Toolbox feature, but save that for another day.

Shout outs:

  • @BitK for creating PwnFox
  • Cesar for introducing this awesome tool to me