A Practical Guide to Bug Hunting with Tools & Command-Line Automation

Bug bounty hunting is not just about luck. It’s about having a repeatable system. Most beginners jump from one tool to another, hoping to find something. But experienced hunters know the truth the real power comes from combining tools, automation, and smart thinking.

This article walks you through a practical, field-tested workflow using command-line tools that can take you from basic recon to real vulnerabilities.

Why Command-Line Matters in Bug Hunting

If you’re serious about bug hunting, GUI tools alone won’t take you far.

Command-line tools give you:

• Speed (scan thousands of endpoints quickly)
• Automation (run pipelines instead of manual work)
• Precision (filter exactly what you need)
• Scalability (handle large targets easily)

In short, CLI = control + efficiency

The Core Workflow Simple but Powerful

Every good hunter follows a flow like this:
Recon → URL Collection → Filtering → Analysis → Exploitation

Let’s break this down step by step.

1. Subdomain Enumeration (Finding Attack Surface)

Your first job is simple: find as many assets as possible.

Tools you should use:

• subfinder
• assetfinder
• amass (optional but powerful)

Example:

subfinder -d target.com -silent > subs.txt
assetfinder --subs-only target.com >> subs.txt
sort -u subs.txt -o subs.txt

Why this matters:

More subdomains = more entry points = higher chances of bugs.

2. Alive Domain Filtering

Not all subdomains are useful. Filter only the live ones.

Tool:

httpx

cat subs.txt | httpx -silent -o alive.txt

This step removes dead targets and keeps your focus sharp.

3. URL Collection Gold Mine Step

Now we collect URLs from historical and live sources.

Tools:

• gau
• waybackurls
• katana (advanced crawling)

cat alive.txt | gau > urls.txt
cat alive.txt | waybackurls >> urls.txt
sort -u urls.txt -o urls.txt

This step is critical because:

• Old endpoints = often vulnerable
• Hidden APIs = less protected
• Forgotten features = easy wins

4. Extracting Sensitive Endpoints

Now filter URLs that look interesting.
Look for:

• Parameters (?id=, ?url=)
• Admin panels
• API endpoints
• File uploads
• Debug paths

Example filtering:

grep "=" urls.txt > params.txt

Or use patterns:

cat urls.txt | grep -E "admin|login|api|debug" > juicy.txt

5. JavaScript Analysis (Underrated Gold)

Most hunters ignore JS files. Big mistake.

Why JS matters:

• Hidden endpoints
• API keys (sometimes)
• Internal logic
• Debug routes

Extract JS files:
cat urls.txt | grep “\.js$” > js.txt

Analyze with:

• nuclei (templates)
• manual reading
• gf patterns

Pro tip:
Search inside JS for:

• fetch(
• axios
• /api/
• tokens

6. Directory & File Fuzzing

Now brute-force hidden paths.

Tool:

• dirsearch
• ffuf

dirsearch -u https://target.com -e php,js,json -x 403,404

This helps find:

• Backup files
• Admin panels
• Dev endpoints
• Misconfigured directories

7. Vulnerability Hunting

Now comes the real game.
Focus on these bugs:

IDOR (Broken Access Control)

• Change IDs (id=123 → 124)
• Access other users’ data

Open Redirect

• Look for redirect=, url=

XSS

• Inject payloads in parameters
• Test reflected & stored

Information Disclosure

• .env, .git, logs
• Backup files

SSRF

• URL-based parameters
• API fetch endpoints

8. Automation Pipeline (Pro Move)

Instead of doing everything manually, combine tools.

Example pipeline:

subfinder -d target.com -silent | httpx -silent | tee alive.txt

cat alive.txt | gau | grep "=" | tee params.txt

This turns hours of work into minutes.

9. Smart Thinking > Tools

Here’s something most people don’t realize:

Tools don’t find bugs. You do.

Tools only:

• Collect data
• Speed things up

Real bugs come from:

• Observing behavior
• Breaking logic
• Thinking like an attacker

10. Common Mistakes to Avoid

• Running tools blindly without understanding output
• Ignoring JavaScript files
• Not testing manually
• Giving up too early
• Chasing only “high severity” bugs

Many big payouts come from chaining small issues.

Final Thoughts

Bug hunting is not about knowing 50 tools.

It’s about:

• Using a few tools deeply
• Building a repeatable workflow
• Staying consistent

If you follow this approach daily, you’ll start seeing patterns.

And once you see patterns…
you start finding bugs others miss.

Bonus: Simple Starter Toolkit

If you’re just starting, stick with this:

• subfinder
• httpx
• gau
• waybackurls
• dirsearch
• ffuf

Master these first. Then expand.