Whether you are a network defender, pentester, or total noob, this presentation will teach you something about how HTTP works and how it can be broken. First, we will discuss basic HTTP concepts and some lesser-known features of the protocol. Then, we will explain and demonstrate HTTP De-Sync attacks popularized by James Kettle in 2019. Attend this presentation and walk away with a deeper understanding of the HTTP protocol, how web requests are processed, and novel HTTP attack techniques.