Wild West Hackin' Fest - Deadwood 2024

JWTs are an incredibly flexible tool that make life easier for developers because they are standardized, widely supported, and include important security features by default. However, like any powerful tool, JWTs can be dangerous when used incorrectly, or for unintended purposes. In this talk, I aim to shine a light on common JWT misuse and abuse. I'll start by briefly describing JWTs and common use cases for them. I'll then present real world scenarios of misuse and abuse from applications that I've tested as a consultant, and written as an engineer. As I present each scenario, I'll demonstrate the various features and failures live, and discuss how the specific implementation of JWTs can be hardened. The end result will be an enlightening and entertaining presentation of information and experience that will provide the viewer with a practical knowledge of how, and how not, to use JWTs.