MaxCSP

HardWeb Security

Overview

"Who needs HTML escaping when you have a bulletproof Content Security Policy?" That's what the developer thought when building this note-sharing platform. Surely nothing could go wrong with such a strict CSP... right? Find a way to compromise the application despite the security measures in place. flag format: flag{}

Lab Details

Prerequisites & Requirements

  • Basic understanding of web applications and HTTP protocols
  • Knowledge of JavaScript and browser behavior
  • Familiarity with Content Security Policy (CSP) and its directives
  • Understanding of Cross-Site Scripting (XSS) attacks
  • Basic knowledge of PHP configuration and internals

What Will You Learn?

  • How Content Security Policy (CSP) protects against XSS attacks
  • PHP's max_input_vars configuration and its security implications
  • Technique to bypass CSP by exceeding PHP configuration limits
  • Crafting XSS payloads for session hijacking
  • Understanding parser differentials and configuration-based vulnerabilities

Tools

  • Web browser with developer tools
  • Webhook service (webhook.site or similar)
  • Burp Suite or similar proxy (for crafting requests)
  • Basic understanding of PHP and web application architecture

Job Positions

Ethical Hacker

Tags

XssContent Security PolicySession HijackingServer MisconfigurationInput Validation