alevsk
Compression Dictionary Transport (RFC 9842) shipped in Chrome 130+ in 2025. Any JavaScript asset designated as a dictionary becomes a set of gadgets an attacker can chain into responses that bypass signature-based WAFs and IDSes. gadget-scanner is the a tool to evaluate that surface: drop in a candidate dictionary and a payload, and it reports how much of the payload hides inside backreferences and how much leaks as literal bytes on the wire. At the table you will score real-world JS libraries as attack primitives, generate the DCB blob with brotli -D, and watch the side-by-side: the raw bytes a WAF would see vs. the payload a browser would execute
alevsk
Security Engineer at Google
Lenin Alevski is a Full Stack Engineer and generalist with a lot of passion for Information Security. Currently working as a Security Engineer at Google. Lenin specializes in building and maintaining Distributed Systems, Application Security and Cloud Security in general. Lenin loves to play CTFs, contributing to open-source and writing about security and privacy on his personal blog https://www.alevsk.com.