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Introduction:
Bug bounty hunting has evolved from a niche hobby into a lucrative professional career, with platforms like HackerOne and Bugcrowd paying out millions. The recent success of a security researcher in securing a significant bounty underscores the critical demand for skilled vulnerability discovery. This article deconstructs the essential technical toolkit and methodologies required to transition from a novice to a rewarded bug hunter.
Learning Objectives:
- Master the core command-line tools for reconnaissance and vulnerability assessment.
- Understand the methodology for identifying and validating common web application vulnerabilities.
- Learn how to responsibly disclose findings and navigate bounty platforms.
You Should Know:
1. Passive Reconnaissance with WHOIS and Subfinder
Before attacking a target, information gathering is paramount. Passive reconnaissance collects data without directly interacting with the target’s systems.
WHOIS lookup for domain registration info whois example.com Using subfinder to discover subdomains subfinder -d example.com -silent Using amass for more intensive enumeration amass enum -passive -d example.com
Step-by-step guide: Start by querying the target domain with `whois` to identify the registrant, name servers, and creation date. Then, use tools like `subfinder` or `amass` in passive mode to compile a list of subdomains. These subdomains often host development, staging, or administrative portals that are less secured than the main domain, providing a larger attack surface.
2. Active Reconnaissance and Service Discovery
Once you have a list of subdomains, you need to discover what services are running on them.
Port scanning with Nmap nmap -sC -sV -T4 -p- target.example.com Quick port scan for top 1000 ports nmap -sV -T4 target.example.com HTTP service discovery with Gobuster gobuster dir -u http://target.example.com -w /usr/share/wordlists/dirb/common.txt
Step-by-step guide: Use Nmap to perform a port scan. The `-sC` flag runs default scripts, `-sV` probes service versions, and `-p-` scans all 65,535 ports. Follow this with a directory bruteforcing tool like `Gobuster` to find hidden directories, API endpoints, and configuration files on any discovered web servers.
3. Automated Vulnerability Scanning with Nuclei
Nuclei uses community-powered templates to scan for thousands of known vulnerabilities.
Basic nuclei scan nuclei -u https://target.example.com -silent Scan with specific template tags (e.g., for exposures) nuclei -u https://target.example.com -tags exposure -silent Update nuclei templates nuclei -update-templates
Step-by-step guide: After identifying web applications, run Nuclei against the URLs. It’s efficient to start with broad scans and then use tags to focus on specific issue types like exposure, misconfig, or cve. Always ensure your templates are up-to-date to catch the latest vulnerabilities.
4. Analyzing JavaScript for API Endpoints and Secrets
Modern web apps heavily rely on JavaScript, which often contains hidden API endpoints and secrets.
Using subjs to find JavaScript files echo "https://target.example.com" | subjs Extracting endpoints from JS files with LinkFinder python3 LinkFinder.py -i https://target.example.com/script.js -o cli Searching for hardcoded secrets with gf cat jsfiles.txt | gf api-keys
Step-by-step guide: Use `subjs` or a similar tool to gather all linked JavaScript files. Then, analyze these files with `LinkFinder` to identify internal API endpoints, which are often undocumented. Pipe the JavaScript code through tools like `gf` (Grep Friendly) with patterns for API keys, tokens, and passwords.
5. Testing for SQL Injection Vulnerabilities
SQL Injection remains a critical vulnerability, allowing attackers to interfere with database queries.
Basic SQLi test with SQLmap sqlmap -u "http://target.example.com/page?id=1" --batch Testing for boolean-based blind SQLi sqlmap -u "http://target.example.com/page?id=1" --technique=B --batch Enumerating database names sqlmap -u "http://target.example.com/page?id=1" --dbs
Step-by-step guide: Identify a parameter that interacts with a database (e.g., ?id=, ?user=). Use SQLmap to automate the testing process. Start with a basic request, and if a vulnerability is found, escalate your testing to enumerate databases (--dbs), tables (-D database_name --tables), and eventually extract data.
6. Exploiting Cross-Site Scripting (XSS) Flaws
XSS allows an attacker to execute malicious JavaScript in a victim’s browser.
Basic XSS payload test
<script>alert('XSS')</script>
Testing for DOM-based XSS
"><img src=x onerror=alert(1)>
Using a polyglot XSS payload
jaVasCript:/-/<code>/\</code>/'/"//(/ /oNcliCk=alert() )//%0D%0A%0d%0a//</stYle/</titLe/</teXtarEa/</scRipt/--!>\x3csVg/<sVg/oNloAd=alert()//>\x3e
Step-by-step guide: Test every user-input field and URL parameter. Start with simple payloads like <script>alert(1)</script>. If those are blocked, try more advanced evasion techniques like polyglot payloads that can be interpreted in multiple contexts. Check for reflection in the HTML source and for DOM-based sinks without server-side reflection.
7. Assessing Access Control (IDOR) Issues
Insecure Direct Object Reference (IDOR) occurs when an application provides direct access to objects based on user-supplied input.
Example: Changing a user ID parameter Original Request: GET /api/user/123/info HTTP/1.1 Attacker Modified Request: GET /api/user/456/info HTTP/1.1 Using Burp Suite's "Match and Replace" to automate testing Rule: Replace "user_id=YourID" with "user_id=AnotherUserID"
Step-by-step guide: While proxying traffic through a tool like Burp Suite, look for parameters that reference objects (e.g., user_id=123, account=456, file=report.pdf). Systematically change these values to see if you can access data belonging to another user. This is a common finding in API endpoints that lack proper authorization checks.
What Undercode Say:
- Methodology Over Tools: The most expensive tools are useless without a systematic approach. Reconnaissance, enumeration, vulnerability testing, and exploitation must follow a logical sequence.
- Automation is Key: The difference between a novice and a pro is the ability to automate repetitive tasks, chaining tools together to create a personalized and efficient hacking pipeline.
The success showcased in the original post is not accidental; it is the result of applying a rigorous, repeatable process. The researcher likely began with broad reconnaissance to map the target’s digital footprint, used automated scanners to identify low-hanging fruit, and then performed deep, manual testing on complex application logic, particularly focusing on authentication and authorization flows. The bounty was likely awarded for a finding that demonstrated a clear impact on confidentiality, integrity, or availability, such as an IDOR leaking sensitive user data or a SQL injection compromising the backend database. This highlights that platforms reward vulnerabilities that pose a genuine business risk, not just theoretical flaws.
Prediction:
The bug bounty economy will continue to mature, leading to more specialized roles and automated platforms. We will see the rise of “AI-assisted hacking,” where machine learning models will predict vulnerability hotspots and generate sophisticated payloads, simultaneously making defenders more proactive. This will create an accelerated arms race, pushing bounty hunters to focus increasingly on complex business logic flaws and novel attack chains that automated systems cannot yet comprehend, thereby increasing the average payout for high-quality, creative research.
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IT/Security Reporter URL:
Reported By: Aditya Singh4180 – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
