: Act as a "malicious hacker" to perform penetration testing in a legal, controlled environment. Implement defenses
Session handling logic Exploit: Weak password policies, session fixation, exposed session IDs in URLs, no MFA.
After completing the codelab, challenge yourself to break your own fixes—the best way to verify a defense is to try to bypass it.
: For file uploads, restrict allowed extensions to a safe "whitelist" rather than trying to block specific dangerous ones. Secure State Management
Always set the HttpOnly flag on session cookies. This prevents client-side scripts from accessing the cookie via document.cookie , neutralizing the impact of an XSS attack. 2. Cross-Site Request Forgery (CSRF) gruyere learn web application exploits defenses top
April 12, 2026 Author: Security Research Unit Subject: Structured learning of web app vulnerabilities (OWASP Top 10) and corresponding defensive layers.
| Exploit | Best Interactive Learning | |---------|----------------------------| | SQLi | PortSwigger SQLi labs, SQLMap tutorial | | XSS | XSS game (Google), Alert(1) to win | | CSRF | PortSwigger CSRF labs | | SSRF | HackTricks SSRF page, AWS metadata challenge | | Deserialization | Phoenix (HTB), Java Deserialization cheatsheet |
Google’s is one of the most effective, hands-on tools available for learning these concepts. It is a purposefully vulnerable web application designed to teach the fundamentals of web application security, exploits, and defenses.
Once a rising star in the artisanal cheese world, had a secret: he spent his nights trading aged rinds for encrypted packets. He wasn’t just a master of fermentation; he was a self-taught hacker obsessed with the crumbling infrastructure of the digital world. : Act as a "malicious hacker" to perform
I can provide targeted code examples or lab recommendations based on your goals. Share public link
Gédéon and Sophie started by exploring the top web application exploits:
: Move sensitive state data (like user permissions) from the client-side (cookies/hidden fields) to secure server-side databases. Access Control
Gruyère realized the developers had left the "back door" unlocked. By simply changing a digit in the URL—from user/profile/102 to user/profile/001 —he bypassed all permissions. He was now logged in as the CEO. He had full access to the firm’s defensive strategies, their encryption keys, and their "unhackable" vault. The Twist: The White Hat : For file uploads, restrict allowed extensions to
Two new categories were introduced in 2025: Software Supply Chain Failures and Mishandling of Exceptional Conditions. Server-Side Request Forgery (SSRF) was consolidated into the Broken Access Control category. Notably, Security Misconfiguration climbed from #5 in 2021 to #2, reflecting the growing complexity of cloud and microservice configurations.
Implement unique, unpredictable, and user-specific tokens for every state-changing request. 3. Defending Against Injection: Prepared Statements
is a famously vulnerable web application created by Google for security training. It simulates a microblogging platform full of security holes, designed specifically to help developers and security enthusiasts understand how attackers exploit systems and how to build robust defenses.