Hello there! Your guy Zokomon is back, and today we’re talking about “7 Best Strategies for Critical Bugs in Bug Bounty “something every bug bounty hunter dreams of: finding critical bugs. Whether it’s a juicy RCE, SQLi, or a major authentication bypass, these bugs are not just exciting—they come with the biggest payouts!
But let’s be real: finding critical bugs isn’t easy. It takes strategy, patience, and persistence. So, let’s break down some tried-and-tested strategies to help you level up and hit those high-severity vulnerabilities!
What Makes a Bug “Critical”?
Before we dive into strategies, let’s define what makes a bug critical.
1. Impact
Critical bugs cause severe damage, such as compromising an entire system, exposing sensitive data, or allowing unauthorized access.
2. Ease of Exploitation
A bug that requires minimal effort to exploit is often rated as critical. The easier it is for an attacker to abuse, the higher its severity.
3. Scope
If the bug affects multiple users or systems, it’s more likely to be considered critical. Widespread impact makes it a top priority for security teams.
Examples of Critical Bugs in Bug Bounty
Some well-known examples include:
- Remote Code Execution (RCE)
- SQL Injection (SQLi)
- Broken Authentication
Strategies for Finding Critical Bugs in Bug Bounty
Here are some proven strategies that top bug hunters use to uncover critical vulnerabilities.
1. Focus on Reconnaissance
Many critical bugs are hidden in places others overlook. That’s why spending extra time on reconnaissance can give you a major edge.
🛠️ Tools to Use:
- Sublist3r, Amass, and httpx – These help you discover subdomains, live endpoints, and hidden assets.
💡 Pro Tips:
✅ Look for endpoints with unusual paths (e.g., /debug, /internal, /admin).
✅ Always test forgotten or misconfigured subdomains—they’re often goldmines for bugs!
2. Think Like an Attacker
To find high-impact vulnerabilities, you need to step into the mind of an attacker. Ask yourself:
- Can I bypass authentication?
- Is there a way to inject malicious input?
- Can I access sensitive data through unintended paths?
💡 Pro Tip:
✅ Don’t just test what’s visible. Instead, experiment by manipulating requests, headers, or parameters to uncover hidden flaws.
3. Understand Business Logic
Many critical bugs stem from business logic flaws. These aren’t always obvious, but they can be extremely dangerous.
🔎 Examples of Business Logic Bugs:
- Bypassing payment systems to get free products or services.
- Accessing restricted features without proper permissions.
💡 Pro Tip:
✅ If you can do something that the application wasn’t designed for, that’s a potential vulnerability!
4. Focus on Authentication and Authorization
Bugs related to authentication and authorization are always high-priority targets. If you can log in as another user or escalate privileges, you’ve found a critical vulnerability.
🔎 Test for:
- Broken access controls
- IDOR (Insecure Direct Object References)
- Privilege escalation
💡 Pro Tip:
✅ Check how the app manages session tokens and cookies. Sometimes, manipulating these reveals serious vulnerabilities.
Step-by-Step Guidance for Finding Critical Bugs
5. Test for Injection Attacks
Classic injection vulnerabilities are still among the most dangerous. Even in 2025, poorly sanitized input is a common weakness.
🛠️ Tools to Use:
- Burp Suite Intruder – Helps automate SQL, Command, and XML injection tests.
💡 Pro Tips:
✅ Look for input fields, API parameters, and URL query strings as potential injection points.
6. Dive into API Security
APIs are often less tested and can be full of vulnerabilities. Since modern applications rely heavily on APIs, they’re a prime target for critical bugs.
🔎 Test for:
- Broken authentication
- Excessive data exposure
- Rate-limiting bypasses
🛠️ Tools to Use:
- Postman & Burp Suite – Both are excellent for API security testing.
💡 Pro Tip:
✅ Always check API responses for sensitive data leaks. You’d be surprised how much hidden information you can find!
7. Master Web3 and Blockchain Security
With the rise of Web3 and DeFi, smart contracts have become major targets for security research. Critical bugs in this space can lead to millions in losses.
🔎 Focus on:
- Reentrancy attacks
- Logic errors in smart contracts
- Wallet vulnerabilities
🛠️ Tools to Use:
- Mythril & Slither – These help analyze smart contract security.
💡 Pro Tip:
✅ Learn Solidity and practice auditing smart contracts to stay ahead in Web3 security.
The Mindset for Finding Critical Bugs
Finding critical bugs isn’t just about tools and techniques—it’s about having the right mindset.
1️⃣ Be Patient
✅ Don’t rush through a target. The more time you spend analyzing, the higher your chances of spotting hidden vulnerabilities.
2️⃣ Stay Curious
✅ Always ask “What happens if?” Experimentation is key to uncovering unexpected flaws.
3️⃣ Keep Learning
✅ The best hunters never stop learning. Stay updated on new vulnerabilities, tools, and attack techniques.
Common Mistakes to Avoid
Even experienced hunters make mistakes. Avoid these pitfalls:
❌ Skipping Recon – Most critical bugs are found during deep reconnaissance. Take your time!
❌ Ignoring Low-Hanging Fruit – Sometimes, a low-severity bug can be chained into a critical exploit.
❌ Not Taking Notes – Keep detailed records of your findings. Good documentation is the key to success.
Tools That Help Find Critical Bugs
Here are some must-have tools for bug bounty hunters:
Burp Suite – Best for web app testing and automation.
Amass / Sublist3r – Helps with subdomain discovery.
Postman – Great for API testing.
Ethical Hacker GPT – Useful for explaining vulnerabilities & generating PoC scripts.
Mythril / Slither – Essential for smart contract analysis.
Final Thoughts
Finding critical bugs isn’t easy, but it’s possible with the right strategies, tools, and mindset. Stay persistent, keep learning, and always think outside the box.
Want to level up even more? Check out my previous blog on “How to Stay Consistent in Bug Bounty Hunting.“
That’s it for today! What’s the most critical bug you’ve found so far? Share your stories—I’d love to hear them! ❤️
