Bug bounty hunting: The Ultimate Guide

In this exhaustive guide, you will find all you need to know about bug bounty hunting based on my experience as a bug bounty hunter and a triage analyst who handled tens of thousands of bug bounty reports. We will explore the bug bounty history and its ecosystem, understand what to expect,

Imagine a world where companies come to you and ask you to hack them. In return, they will pay you whenever you find a unique vulnerability. And the best part, you don’t have to neither leave your home nor stick to a time schedule!
It sounds unrealistic, right? Well, let me tell you that it’s now a real job, not a fantasy anymore!

When bug bounties didn’t exist

Let’s travel 50 years back. Home computers barely start entering the market. Phone phreaking at its golden age. Hackers painted as cybercriminals and weird people who think outside the norm to cause trouble. The US government passes laws which make it a crime to break into computer systems. I wasn’t yet born, and I’m honestly grateful for that.
Unfortunately, companies neglected hackers and continued bringing products to the world without proper security testing. The situation got to a point where the real cybercriminals saw benefits in compromising the vulnerable companies, and hacking companies they did!

Bug bounty programs to the rescue

Luckily, some major companies felt the need to embrace the hacker spirit and leverage the hacking skills of independent individuals.

The birth of the “bug bounty” term

Back in 1995 the Netscape Communications Corporation company came up with the term “bug bounty” for the first time. Do you remember the Netscape browser? You probably don’t, but it’s the grandfather of modern Web Browsers like Chrome and Firefox. Well, back in the days, the company launched a bug bounty program for the Netscape Navigator 2.0 Beta browser. We had to wait for about 15 years before major companies started creating their own programs. We are talking about Google and Facebook in about 2011. Yahoo! Followed in 2013.

Early baby steps

However, this model had its limitations due to the fact that those programs weren’t mature enough.

First, the rewards were as modest as a t-shirt! Don’t get me wrong, I have nothing against t-shirts, I was so grateful to receive one from SoundCloud after I found a bug, but let’s just say that there are many other factors which drive hackers. According to the 2020 HackerOne Hacker report, 53% hack for money.

Secondly, the programs were limited to only a few companies, meaning that hackers didn’t have enough choice. You either hack Facebook or go to jail hacking others. And this is a big downside because 68% of bug bounty hunters hack for the challenge and the opportunity to learn, according to the same report.

Last but not least, hackers didn’t have a middleware party to defend their bugs if the program didn’t play fair. This doesn’t happen very often, but it can lead to surprising outcomes. In 2013, a hacker wrote a poorly-written report to Facebook about a bug which allowed an attacker to post on an arbitrary Facebook user’s timeline. When Facebook didn’t acknowledge the vulnerability, he then posted a message on Mark Zuckerberg’s timeline. Consequently, he wasn’t eligible for a reward. This is a common issue; when working as a triage analyst at HackerOne, I can’t count the number of poorly-written reports that I had to handle. But of course, it’s not an excuse not to give it enough analysis time and honor the hacker’s effort.

But, why become a bug bounty hunter while you can do penetration testing?

Bug bounty vs Penetration testing

Both bug hunting and penetration testing help secure organizations. However, each one differs from the other in many fundamental aspects. So, if you are a penetration tester who wants to apply the same tactics in bug hunting, you will probably fail. Similarly, if a company organizes a bug bounty program the same way you do in penetration testing assignments, you will probably fail as well. Here are some key differences that you should take into account.

The time factor

A bug bounty program usually runs for years, compared to penetration testing which spans a couple of weeks at most. Besides, there are no limitations for testing outside business hours. As a bug bounty hunter, this means you have all the time to hack as long as you want, without the need for a deadline. Therefore, your tests would be different than a typical penetration test. Usually, bug bounty hunters stick with one or two programs for months, or even years, depending on how big the scope is.

To me, bug bounty hunting is a marathon, while penetration testing is a sprint.

Bug bounty programs don’t accept some vulnerabilities

This is an important factor to consider, especially for penetration testers who are new to bug hunting. In fact, you can easily report informative issues like weak SSL ciphers, verbose errors, etc. In bug bounty programs, these issues are almost always explicitly out-of-scope in the program’s policy.

The money factor

Money is a key difference between bug bounty hunting and penetration testing. Companies pay penetration testers for the entire mission, while bug bounties are paid per valid vulnerability. Therefore, you have to be efficient or you will waste your time. This doesn’t mean that penetration testers are not efficient, quite the contrary. In fact, they can successfully handle simultaneous projects and find great security vulnerabilities. The point is … you must focus on impactful vulnerabilities and stay away from informative bugs if you want to get bug bounties.

The rise of Bug bounty platforms

With all the limitations that traditional bug bounty programs suffered from, there was a need for middleware in the cybersecurity market to help hackers and companies collaborate with each other. Naturally, bug bounty platforms were born to shape a new era in cybersecurity. HackerOne and Bugcrowd were among the first players, but we’ll leave details about each one to another episode. However, they all share pretty much the same core features.

Gamification of hacking

Hacking with bug bounty platforms is like playing a video game. We find vulnerabilities and increase our metrics, which increases our ranking in the leaderboard and opens the door to new programs, new challenges and new experiences. The best part is that we get paid along the way. Programs also get rated, the more active and rewarding they are, the more luckily talented hackers will help them stay secure. It’s a win-win situation.

Bug bounty platform HackerOne 90 Days Leaderboard
Bug bounty platform HackerOne 90 Days Leaderboard

Bug bounty challenges

More and more companies are joining bug bounty platforms, and so it is for people who want to hack. The problem is that not many of them have proper hacking knowledge. It’s easy to see how this is unbalanced. In fact, a bug bounty ecosystem relies on the abundance in both good programs and talented hackers. That’s why those platforms are developing more and more educational content in the form of videos, mini-challenges and CTFs. An example of that is the LevelUp conference which Bugcrowd organizes each year. It hosts talks from great hackers who share updated hacking knowledge. Another example is HackerOne’s hacktivity and the hacker101 website where Hackerone publishes new disclosed reports and provides a free playground for hackers to solve challenges and get private invites.

Bug bounty Hacker101 CTF challenges
Bug bounty Hacker101 CTF challenges

Bug bounty events

Another interesting advantage those platforms bring to the table is live hacking events. They gather the best hackers for a weekend to hack a target onsite. It’s a great experience which brings people together and produces new meaningful relationships. I once received an invitation but I turned it down due to some family health struggles I was going through. It was a big disappointment for me not to attend it, but I didn’t have a choice in that situation. Personally, family comes first.

The Bug bounty community

So far, bug bounty platforms are emerging and they are doing a great job at educating the next generation of hackers. Hunting for bugs has become a trend of its own and the community is growing so fast. In fact, about a third of the hacking crowd have less than 2 years of experience according to the HackerOne Hacker report of 2020. Naturally, the community started building its own knowledge base. New blogs, YouTube channels, live streams and podcasts started bringing even more educational and entertaining content. Allow me to talk about three valuable things that the community has produced.

Bug bounty methodologies

Hacking is an Art, each hacker has a perspective, a set of skills and experiences which shape the methodology he or she follows when approaching a target. Consequently, it is so easy to get lost in the number of clever methodologies out there. Jason Haddix was one of the early hackers who shared his bug bounty methodology, which is now at its 4th version.

Bug bounty tools

Every craftsman is nothing without a proper toolbox, and hackers are no exception. The bug bounty community is producing so many tools that you will have a hard time tracking. By the way, that’s a major reason why Jason’s bug bounty hunting methodology has been revised four times since 2015.

Bug bounty books

For those who enjoy reading, there are many books which will teach you just how to get into the game of bug bounties. One of the first ones was Peter’s Web hacking 101. I downloaded a free copy when signing up with HackerOne, and boy was it helpful! Shout out to Peter Yaworsky from here!

For those who don’t enjoy reading, you better get used to it if you want to survive in this career. Here is a list of books you should read!

Bug bounty benefits

Bug bounty is proving its spot in the cybersecurity market, that’s for sure. It is becoming another way of securing companies through an increasing crowd of hackers. It is useful in many ways.

Bug bounty money

The rise of bug bounty platforms and the increasing public breaches led to a significant increase in the rewards. I receive now and then emails from HackerOne telling me that a program has increased their rewards either for a promotion period or indefinitely. In one live hacking event, payouts surpassed a Million dollar amount! Think about that! A million dollar in just three days!

Freedom and flexibility

Bug bounty hunting allows hackers to live the working lifestyle they feel comfortable in. All the work is done remotely, except for live hacking events, which due to the Corona Virus, has also gone online. We can work alone or collaborate. Flexibility to work late at night or early in the morning is a great benefit. We also can choose from a wide range of programs depending on our preference. Although the majority prefers to make a side hustle income, around 20% work as full-time bug bounty hunters.

Relational dimension

Bug bounty hunting is not just all about making money. In fact, hackers build relationships and expand their friendships and professional network. The bug bounty community is generally open-minded with a young heart. People here are curious, fun and hard-working. We support each other in case someone goes through a hurdle, like a burnout (more on this shortly). Overall, I’d say I’m grateful to be part of such a great community.

Bug bounty drawbacks

Bug bounties cannot be that perfect, can they? There are downsides as well. I feel I’m responsible to put your expectations into perspective and give you a heads up before you leave your job and start hunting for bugs. Bug bounties, like any other thing in this life, has its drawbacks as well.

Instability

When we hunt for bugs, we only get bounties when we are the first to find one, that’s just how it is. This rule brings a great deal of income instability because it generates frustration and fear. Even talented hackers can hunt for days, or even weeks, without finding a single bug. Imagine how frustrating this can be! That’s why the majority prefer to hack part-time.

Isolation and comparisons

Because bug bounty hunting is commonly remote, we are not limited to an office. Some hackers travel the world while hacking. Others prefer to enjoy hunting from the comfort of their couch at home. However, since we don’t have to work with a team, we can sometimes feel lonely. And when we don’t find vulnerabilities, it gets even worse, especially when scrolling the Twitter feed and finding many tweets of others who find bugs and get paid.

Depression and burnout

The aforementioned drawbacks help prepare for the coming of the scariest ghost, the darkest nightmare of all bug hunters, the most wild beast which we call the burnout. You know, the feeling when you work continuously without any results, you lock yourself in front of your machine, you hack day and night and all you see are others finding bugs. Therefore, you lose your confidence and hope doors suddenly get closed. And then the time comes, and you decide to stop everything and never get back to hacking again.

That’s why it is important to pay attention to your mental health while working as a bug bounty hunter. We will talk about that on a dedicated episode. Meanwhile, you can read what other bug bounty hunters think about it. 

Bug bounty programs

Bug bounty programs are your clients, and you should treat them as such. In other words, you have to respect their security policy, deliver high-quality reports and assist them on any need for information. If you consider these points, they will love you!

In bug bounty, there are two types of programs: public and private.

Public programs

Public programs are, as the name suggests, accessible to all bug hunters. You can send security reports through a bug bounty platform or directly through their suggested communication channel, which you can find on the main domain under the /.well-known/security.txt file.

Public programs tend to have a big scope, which makes it a good target for long-term hacking commitment. However, you first need to assess if they have good response metrics. Otherwise, you will have to wait for months to get your reports handled, and yet other months to get a reward if the program provides bug bounties. You can gauge their response by sending some low hanging fruits which are still impactful, like a reflected XSS.

Private programs

Private programs are only accessible through private invites from bug bounty platforms. When you reach a certain level of reputation, you start to get them.

In general, these have a small number of hackers compared to public programs. Besides, they usually get help from the triage analysts of the bug bounty platform to reduce the noise of invalid reports. Moreover, the scope varies from wildcard domains to a single web application. Finally, they generally have good response metrics and pay well, which makes it attractive to talented hackers.

However, I would say that competition is higher in private programs than in public programs. Although the number of hackers is smaller, you have to work harder to uncover deeper bugs which have been overlooked by the previous testers.

Which is better, private or public programs?

In my opinion, it really doesn’t matter! Whether you hack on a public or a private program, you will always find bugs because code never stays the same! Every day, developers write and commit new lines of code, which means new opportunities for bugs to surface.

As long as you have the hacker hunter spirit, I guarantee you success.

How to be a successful bug bounty hunter?

Nowadays, there are so many bug bounty platforms, which host so many programs. This means that bugs are growing in number as well, you just have to develop some patterns to be able to find them.

A bug bounty hunter is a hacker

That’s obvious, but there are so many bug bounty hunters who honestly don’t understand the vulnerabilities that they are looking for. They have the spirit of script kiddies who care only about exploiting vulnerabilities, and a lot less about knowing enough about them.

You must have the spirit of a hacker, meaning that you should be curious how the technology works, and why the bug exists and how to exploit it. Then learn as much as you can about it. That way, you will not only exploit bugs but also develop methodologies about how to look for them.

A bug bounty hunter should have discipline and be consistent

This is one of the most challenging things you have to overcome. In fact, you won’t be paid until you find a bug, so might end up wasting a day, a week or even a month or more without finding anything.

If you hack for money, it might get you a painful burnout, which I already covered separately. Alternatively, if you have a full-time job and a family, it might be challenging to find that sweet spot to hack in your free time. No matter what your situation is, you have to be consistent.

Consistency should also be applied to acquire new knowledge. I suggest you take advantage of the many bug bounty resources to stay up to date.

A successful bug bounty hunter has a methodology

This is a direct result of consistency; the more you hack, the stronger your mind muscles grow. Therefore, you will find yourself following a pattern of tests which will improve over time. Ultimately, this will increase your chances of finding unique bugs.

Every bug bounty hunter has its methodology and you can get inspired from many of them. I published my own and I invite you to read it.

A bug bounty hunter is nothing without a proper toolbox

You have to choose your tools carefully. They should be flexible, simple to use, quick, contain less bugs, etc. Unfortunately, you can’t meet all the requirements. Therefore, you can combine multiple tools, or develop your own.

The bug bounty community offers so many great tools that you should use. I tried collecting the most famous ones in one article, but there are so many emerging tools. You have to keep sharpening and updating your tools if you want to be a successful bug bounty hunter.

A successful bug bounty hunter focuses on few bug bounty programs

If you keep jumping from one program to another, you will only find shallow bugs if you happen to come across a fresh code. Otherwise, there is a high chance you won’t find any bug.

Instead, choose a few programs which have good response metrics, pay fair money and are in line with your taste. You will find deeper bugs this way. Additionally, you will feel less overwhelmed.

A bug bounty hunter writes good bug bounty reports

It’s not all about your technical skills. In the end, you will interact with humans to sell your bug at the highest price. Unfortunately, you can’t do that with poor reports.

You have to understand that your report is the only value you give to the bug bounty program. If you write it well, they will spend less time reproducing and validating the issue, they will quickly triage and reward you. Plus, they will love you and might give you a bonus for your quality report. Read about that in a full article dedicated to this subject.

Some bug bounty hunters use automation for assistance

This is where few hackers shine because they know how to build code, not just break it. If you want to level up your game in bug bounty hunting, you have to automate tasks to enumerate your targets, monitor new domains, assets and changes in the programs you hack on.

Conclusion

If you are barely starting in the infosec industry and want to start doing bug bounties, I recommend you check out the OWASP Top 10 vulnerabilities in practice, which is a guide to the basics of web application security testing.