Deep-dive security audit of CORS vulnerabilities. Understand null origin attacks, unvalidated origin reflection, regex bypasses, and cache poisoning risks.
Frequently Asked Questions
Q1. What is CORS Origin reflection vulnerability?
It occurs when a backend developer configures the server to dynamically read req.headers.origin and write it directly into Access-Control-Allow-Origin without checking an allowlist, while also setting Access-Control-Allow-Credentials: true. This allows any malicious site to perform authenticated data theft.