What is the OWASP Top 10?

The OWASP Top 10 is a widely recognized list that highlights the most critical security risks to web applications. It serves as a guide for developers, testers, and security professionals to understand, identify, and fix common vulnerabilities.

Why It Matters

Raises awareness of common web risks
Helps developers write secure code
Assists in creating secure-by-design systems
Supports penetration testers in assessment
Acts as a checklist for bug bounty hunters

OWASP Top 10 (with Code Examples)

1. Broken Access Control

Users can access unauthorized functions or data.

# Flask (Python)
@app.route("/admin")
def admin():
    if session.get("role") != "admin":
        return redirect("/unauthorized")
    return render_template("admin.html")

Missing proper access checks leads to privilege escalation.

2. Cryptographic Failures

Insecure storage or transmission of sensitive data.

jsCopyEdit// JavaScript (bad practice)
const password = "123456";
localStorage.setItem("password", password);  // Insecure

Always use HTTPS and proper encryption libraries (like bcrypt for passwords).

3. Injection (e.g. SQL, OS)

// PHP (vulnerable to SQL Injection)
$id = $_GET['id'];
$query = "SELECT * FROM users WHERE id = '$id'";

Use prepared statements:

$stmt = $pdo->prepare('SELECT * FROM users WHERE id = :id');
$stmt->execute(['id' => $_GET['id']]);

4. Insecure Design

Security wasn't considered during the system design.

Use threat modeling early in development and validate input at every layer.

5. Security Misconfiguration

# NGINX - Dangerous config
location /admin {
    autoindex on;  # ❌ Exposes directory listing
}

Disable autoindex, remove default credentials, and close unused ports.

6. Vulnerable & Outdated Components

// package.json
"dependencies": {
    "express": "3.0.0" // ❌ Known vulnerabilities
}

Use tools like npm audit or dependabot to update packages.

7. Identification & Authentication Failures

//JavaScript - Weak validation
if (user === "admin" && pass === "admin") {
    login(); // ❌ Default credentials
}

Enforce strong passwords, MFA, and account lockout.

8. Software & Data Integrity Failures

Using unsigned or unverified software components.

Verify packages with checksums or signatures.

9. Security Logging & Monitoring Failures

# Log file
[INFO] Login attempt failed from IP: 192.168.1.10

Log suspicious events and integrate with alerting systems (e.g. SIEM).

10. Server-Side Request Forgery (SSRF)

# Python - SSRF vulnerability
url = request.args.get("url")
r = requests.get(url)

Whitelist allowed domains and validate all incoming URLs.

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Final Thoughts

Whether you're a developer or an aspiring cybersecurity analyst, mastering the OWASP Top 10 helps you build and secure applications the right way. It’s more than a list—it’s your first defense in the wild world of web.

Stay sharp. Stay secure. 🛡

The Importance of OWASP Top 10 in Cybersecurity