Bypassing admin checks and more – Privilege Escalation case study

Course•By gregxsunday

CASE STUDIES

Case studies teach you what really works in real-world bug bounty hunting. Each one breaks down a disclosed bug bounty writeup focused on a specific bug class. You’ll see how top hackers approach targets, chain bugs, and write reports that get rewarded. You also get access to a database of all the reports if you want to go deeper.

Course•By gregxsunday

DEVTOOLS

DevTools can help you understand how frontends actually work. This series walks through the tabs and features you’ll use when debugging JavaScript, setting breakpoints, and analyzing client-side flows during bounty hunting. It’s built around real use cases, with a focus on clarity and signal over noise.

Course•By gregxsunday

GraphQL Case Study

If your GraphQL testing ends with introspection queries and basic ID swapping, you’re missing out on a lot of impactful bugs. GraphQL APIs can open doors to vulnerabilities ranging from SQL injections and CSRF attacks to subtle caching issues, tricky race conditions, and WebSocket-based bypasses. In this case study, I’ve analyzed disclosed vulnerability reports to see what happens in real life and identify what we all must have in our testing methodologies.

Course•By gregxsunday

How to make money with IDORs? IDOR case study

IDORs are often recommended as the easy vulnerability class, perfect for beginners. "Just change the ID in the URL parameter" they say. But are they really that simple? There's only one way to find out – do a comprehensive case study. I analyzed 187 public bug bounty IDOR reports to understand how hunters actually make money with this bug class. This study reveals where to look for IDORs, what impact gets rewarded, and the most common placement for payloads (spoiler: it's not URL parameters). You'll discover the most common identifier types, learn techniques for predicting identifiers, and understand real-world protection bypasses. The study includes a parameter wordlist and full database of all 187 reports for your research. If you think IDORs are just about changing numbers in URLs, this data-driven analysis will show you what successful hunters actually do differently.

Course•By gregxsunday

Mobile Case Study - an overlooked niche in bug bounty?

Mobile bug bounty always seemed like an area that was presented as a niche or an opportunity in the bug bounty world. Yet, personally, I never really spent much time on it. One reason was that I assumed many bugs would require an app to be installed on the victim’s device, making the attack scenario difficult to achieve. I wanted to see for myself whether that’s true and what kinds of mobile bugs can actually earn good bounties so I made this case study.

Course•By gregxsunday

OAUTH SERIES

This OAuth series covers the kinds of bugs that show up in real bounty reports. It breaks down OAuth step by step - from how OAuth works, to what each parameter does, to the bugs those parameters can introduce. You’ll also learn lesser-known techniques, including server-side issues and what recon looks like in the context of OAuth.

Course•By gregxsunday

RCE case study

This was the hardest case study I've done. Usually, I can reduce bugs into clean categories, but RCE is different – there's a huge variety of vulnerabilities that lead to command execution. This complexity shows just how much knowledge is required to find RCEs consistently. I hope this article helps you navigate that learning curve. I analyzed 126 RCE reports to understand where hunters actually find these critical bugs. This study reveals which functionalities are most vulnerable to RCE, what root causes lead to command execution, and what types of exposed services create opportunities. You'll discover the most common RCE types and exploits, learn which languages are vulnerable to deserialization attacks, and see how successful hunters prove their RCE findings. If remote code execution seems overwhelming or you're unsure where to start hunting for it, this data-driven breakdown will give you clear direction.

Course•By gregxsunday

SSRF – Case study of 124 bug bounty reports

In theory, SSRF is simple – you make requests to arbitrary locations. In practice, it's far more complex. Where should you look for SSRFs? What parameters are vulnerable? Do you need complex payloads with octal encoding and unicode characters? I wanted real answers, so I extracted and analyzed 361 SSRF reports from the web. This case study reveals which functionalities are most vulnerable, what parameters to target, and which payloads actually work in real scenarios. You'll learn how researchers demonstrate impact and discover what really matters in practice. Includes a database with 315 reports.

Course•By gregxsunday

XSS – case study of 174 reports

XSSes are everywhere. They've been the most common vulnerability class for years. But while popping an alert may seem simple, there's much more to cross-site scripting than meets the eye. What payloads actually work in production? Where are hunters finding XSS in modern applications? Can you submit reports without CSP bypasses, or is that now mandatory? What parameters should be in your wordlists? To answer these questions, I extracted hundreds of XSS reports from the internet and analyzed 174 of them to understand how people actually make money with this bug class. This study reveals the most common XSS types, root causes, and locations where they're found. You'll discover what payloads and filter bypasses work in practice, how often blind XSS appears, and how frequently CSP bypasses are required. Includes a wordlist of vulnerable parameters and the complete database of all reports analyzed.

Course•By gregxsunday