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Introduction:
Bug bounty hunting is a high-stakes game of digital cat and mouse, where timing and technical precision are everything. A single “duplicate” report on a critical finding, as experienced by a researcher targeting IBM, underscores the intense competition. This article provides the technical command-line arsenal you need to find, validate, and report vulnerabilities faster and more effectively than the crowd.
Learning Objectives:
- Master reconnaissance and subdomain enumeration techniques to expand your attack surface.
- Develop proficiency in automated vulnerability scanning and manual exploitation proof-of-concept creation.
- Learn the commands for thorough data exfiltration and securing your own testing environment.
You Should Know:
1. Mastering Subdomain Enumeration with `amass` and `subfinder`
Verified Command:
amass enum -passive -d target.com -o amass_output.txt && subfinder -d target.com -o subfinder_output.txt && sort -u amass_output.txt subfinder_output.txt > final_subs.txt
Step‑by‑step guide:
This command pipeline uses two powerful tools, Amass and Subfinder, for passive subdomain discovery. `amass enum -passive` performs reconnaissance without directly touching the target, reducing the chance of detection. `subfinder` uses numerous public sources to find subdomains. The results from both tools are combined and sorted, with duplicates removed using sort -u, to create a comprehensive, unique list of subdomains. This list forms the foundation of your attack surface.
- Probing for Live Hosts and HTTP Services with `httpx`
Verified Command:
cat final_subs.txt | httpx -silent -title -status-code -tech-detect -o live_subdomains.txt
Step‑by‑step guide:
Not all discovered subdomains are active. This command takes your list of subdomains and uses `httpx` to probe them for live web servers. The flags enrich the output: `-silent` removes clutter, `-title` fetches the page title, `-status-code` shows the HTTP response code (e.g., 200, 404), and `-tech-detect` identifies underlying technologies (e.g., WordPress, React, Nginx). This quickly prioritizes targets that are online and reveals potential technology-specific vulnerabilities.
3. Discovering Hidden Paths and APIs with `ffuf`
Verified Command:
ffuf -w /usr/share/wordlists/seclists/Discovery/Web-Content/common.txt -u https://target.com/FUZZ -mc 200,301,302,403 -ac -t 100
Step‑by‑step guide:
Fuzzing is key to discovering hidden directories, files, and API endpoints. This `ffuf` command uses a common wordlist (-w) to brute-force paths against a target URL. The `-mc` flag filters for successful, interesting HTTP status codes. `-ac` automatically calibrates filters for ignoring irrelevant responses, and `-t` sets the number of concurrent threads for speed. Always check the permissions of the wordlist you are using to avoid errors.
4. Automated Vulnerability Scanning with `nuclei`
Verified Command:
cat live_subdomains.txt | nuclei -t /path/to/nuclei-templates/ -severity medium,high,critical -o nuclei_results.txt
Step‑by‑step guide:
Nuclei uses community-powered templates to scan for thousands of known vulnerabilities. This command pipes your list of live subdomains into nuclei. The `-t` flag specifies the template directory, and `-severity` filters results to show only medium, high, and critical findings, focusing your triage efforts. It’s an essential tool for rapid, automated initial assessment.
5. Manual SQL Injection Testing with `sqlmap`
Verified Command:
sqlmap -u "https://target.com/vulnerable.php?id=1" --batch --level=3 --risk=3 --dbs
Step‑by‑step guide:
When you find a potential SQLi vector (e.g., id=1), `sqlmap` automates the exploitation process. `–batch` runs in non-interactive mode, accepting default prompts. `–level` and `–risk` increase the depth and scope of tests. `–dbs` attempts to enumerate available databases upon successful injection. This command is for authorized testing only and provides a powerful proof-of-concept for bug reports.
6. Intercepting and Manipulating Requests with `curl`
Verified Command:
curl -X POST https://target.com/api/change_email -H "Content-Type: application/json" -d '{"email":"[email protected]"}' -H "Cookie: session=your_session_cookie" --proxy http://127.0.0.1:8080
Step‑by‑step guide:
This `curl` command manually crafts an HTTP POST request to test for logic flaws (e.g., insecure direct object references). `-X` specifies the method, `-H` adds headers (like Content-Type and your stolen session cookie), and `-d` contains the POST data. The `–proxy` flag routes the request through a tool like Burp Suite for further manipulation and analysis, allowing you to precisely test endpoint behavior.
7. Securing Your Research Environment with `iptables`
Verified Command:
iptables -A OUTPUT -p tcp --dport 443 -j ACCEPT && iptables -A OUTPUT -p tcp --dport 80 -j ACCEPT && iptables -A OUTPUT -p tcp --dport 53 -j ACCEPT && iptables -A OUTPUT -j DROP
Step‑by‑step guide:
Bug bounty hunting can attract retaliation. This Linux iptables firewall rule set locks down outbound traffic from your research VM. It first allows (ACCEPT) essential traffic to web (ports 80, 443) and DNS (port 53) services. The final rule `DROP`s all other outbound connections, preventing any accidental or malicious callback shell from communicating with an attacker’s server, thus protecting your machine.
What Undercode Say:
- Automation is Non-Negotiable: The difference between a duplicate and a first-to-find report is often a matter of minutes. Mastering automated reconnaissance and scanning pipelines is not an advantage; it is a fundamental requirement for success in modern bug bounty programs.
- The Proof is in the PoC: Platforms like HackerOne prioritize well-documented, reproducible proofs-of-concept. Commands that manually craft malicious requests (
curl) or automate exploitation (sqlmap) are critical for transforming a potential finding into a validated, high-severity report that cannot be ignored.
The recent experience of a researcher receiving a duplicate on a critical IBM flaw is a microcosm of the entire field. The hunt is no longer just about technical depth but about velocity and precision. The tools and commands listed here are the great equalizers. They allow individual researchers to systematically compete with coordinated teams, transforming vast attack surfaces into a prioritized list of exploitable targets. The future hunter will be defined not by the number of tools they know, but by the efficiency with which they chain them together.
Prediction:
The increasing automation and sophistication of bounty hunting tools will lead to a “time-to-report” arms race. We will see the rise of AI-powered agents that continuously monitor for target scope changes, deploy instant reconnaissance scans, and autonomously test for common vulnerability classes, submitting reports within seconds of a new asset going live. This will push human hunters to focus on complex, logic-based vulnerabilities that require deep contextual understanding and creative exploitation chains, ultimately raising the overall security posture of the internet.
🎯Let’s Practice For Free:
IT/Security Reporter URL:
Reported By: https://lnkd.in/p/dk4ytWVb – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
