What problem does it solve? Security testers often report CORS findings that browsers would actually block, producing false positives and rejected bug bounty reports. This Skill provides a rigorous methodology to identify genuinely exploitable CORS misconfigurations and prove impact with browser-based evidence. ## Core Features & Use Cases - Origin Reflection Testing: Systematically probe endpoints for reflect-any-origin, null-origin trust, and trusted insecure HTTP origins with credentials. - Regex Bypass Classification: Match subdomain trust-regex flaws (unescaped dot, missing end-anchor, prefix-only) to the correct bypass payload instead of guessing. - Browser Proof-of-Concept Validation: Use fetch-based and sandboxed-iframe PoCs to confirm a credentialed cross-origin read actually succeeds, since curl ignores CORS enforcement. - Use Case: While testing a target's /api/me endpoint, you see the Origin header reflected with Access-Control-Allow-Credentials: true. Use this Skill to build a hosted browser PoC that reads the authenticated response body from an attacker-controlled origin, then exfiltrate it to an OOB listener as unambiguous proof for a High-severity report. ## Quick Start Test the target's API endpoints for CORS misconfigurations and build a browser proof-of-concept for any origin reflection with credentials you find.
