1. Web Security Academy
  2. Request smuggling
  3. Browser-powered
  4. CL.0 request smuggling
  5. Lab

Lab: CL.0 request smuggling


This lab is vulnerable to CL.0 request smuggling attacks. The back-end server ignores the Content-Length header on requests to some endpoints.

To solve the lab, identify a vulnerable endpoint, smuggle a request to the back-end to access to the admin panel at /admin, then delete the user carlos.

This lab is based on real-world vulnerabilities discovered by PortSwigger Research. For more details, check out Browser-Powered Desync Attacks: A New Frontier in HTTP Request Smuggling.

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