When I first got into bug bounty hunting, I thought I had it all figured out…
Learn XSS, SQLi, file upload bugs, OWASP Top 10, easy wins, right?
But the real world humbled me.
I’d throw my payload like in the Burp Suite labs…
Instead of a popup, I’d get “Access Denied” from Cloudflare.
That’s when it hit me, if you want real progress, real impact, and real money in bug bounty…
Stop chasing low-hanging fruit. Start hunting smart.
This isn’t a payload dump or step-by-step exploit guide. That’s on you.
This is the list of 10 bug categories you should focus on if you want to consistently find valuable vulnerabilities.
1. Account Takeover (ATO)
It’s rarely a single bug, more often it’s weak flows, sloppy tokens, or flawed logic.
Check:
- Password resets (is the token tied to the session?)
- Email changes (can you bypass password confirmation?)
- Support flows or forgotten endpoints.
If you can control someone’s account, you’ve struck gold.
2. 2FA Bypass
Most hunters skip targets with 2FA, big mistake.
Look at:
- Legacy APIs (do they enforce 2FA at all?)
- “Remember this device” features that skip enforcement.
- Cookie/session inconsistencies.
If 2FA isn’t enforced everywhere, you can walk right in.
3. 403 Bypass
A 403 doesn’t mean “stop”. It means “get creative.”
Try:
- Changing HTTP methods (GET → POST, OPTIONS, TRACE).
- Adding headers (
X-Original-URL,X-Forwarded-For). - Path tricks (double slashes,
%2e,%2f).
WAFs and proxies can be confused. That’s your in.
4. API Authentication Flaws
APIs are often inconsistent.
Check:
- Unauthenticated endpoints developers forgot to lock down.
- Token format quirks.
- Differences between mobile, web, and API validation.
5. API Authorization Flaws
Even after login, not all actions are equal.
Look for:
- User ID or role changes in request bodies.
- Predictable UUIDs or hashes.
- Role escalation through overlooked parameters.
6. Privilege Escalation
Low-privilege accounts often have hidden doors.
Tricks:
- See if old permissions still work after a downgrade.
- Ignore the frontend, test GraphQL or raw API calls.
- The backend is the real gatekeeper.
7. Business Logic Bugs
Break how the app expects users to behave.
Examples:
- Skip checkout steps.
- Abuse discounts or loyalty systems.
- Race conditions that allow duplicate actions.
You’re breaking assumptions, not just code.
8. CSRF (Yes, Still Exists)
If SameSite cookies aren’t set properly, you’ve got an opening.
Look for:
- State-changing actions without CSRF protection.
- APIs callable from a malicious page.
Password changes, deletions, or financial actions are prime targets.
9. File Upload Vulnerabilities
A file upload feature is basically an invitation.
Test:
- Extension bypasses (
.php.jpg,.svg,.html). - Path traversal or zip bombs.
- SVG/TXT uploads for stored XSS.
Renaming files doesn’t always make them safe.
10. IDOR (Insecure Direct Object Reference)
Simple concept, huge impact.
Check:
- Users, orders, files, increment or guess IDs.
- Not just GET, try POST, PUT, DELETE.
- Even UUIDs can be brute-forced if predictable.
The Real Hacker Mindset
These bugs aren’t random. They’re patterns most hunters overlook.
The edge comes from:
- Reading reports.
- Studying write-ups.
- Thinking differently.
Every “low severity” finding is a chance to chain, escalate, and turn it into a real payout.
Final Words
That’s it, no fluff, no filler. Just the mindset and targets that matter.
Until next time…
Stay curious, and stay secure. 🔐🔥