Explore the intricacies of HTTP header smuggling in this 27-minute Black Hat conference talk. Delve into how web application vulnerabilities arise from flawed implementations of proxy servers handling HTTP headers. Learn about recent developments in header smuggling techniques and their potential for triggering exploitable behaviors. Discover practical examples of mutation techniques, including identity, space before colon, and header name junk. Follow a methodology for detecting and exploiting header smuggling vulnerabilities, including generating back-end errors and comparing responses. Examine real-world case studies, such as an AWS Cognito partial rate limit bypass and cache poisoning with API Gateway. Gain insights into detecting CL.CL request smuggling and understand potential defenses against these attacks. Equip yourself with valuable knowledge to enhance web application security and protect against sophisticated header smuggling exploits.