Performing Content Security Policy Bypass

When to Use

• When XSS is found but execution is blocked by Content Security Policy
• During web application security assessments to evaluate CSP effectiveness
• When testing the robustness of CSP against known bypass techniques
• During bug bounty hunting where CSP prevents direct XSS exploitation
• When auditing CSP header configuration for security weaknesses

Prerequisites

• Burp Suite for intercepting responses and analyzing CSP headers
• CSP Evaluator (Google) for automated policy analysis
• Understanding of CSP directives (script-src, default-src, style-src, etc.)
• Knowledge of CSP bypass techniques (JSONP, base-uri, object-src)
• Browser developer tools for CSP violation monitoring
• Collection of whitelisted domain JSONP endpoints

Workflow