“The Most Dangerous Codec in the World: Finding and Exploiting Vulnerabilities in H.264 Decoders.”
see PDF by
Willy R. Vasquez, The University of Texas at Austin
Stephen Checkoway, Oberlin College
Hovav Shacham, The University of Texas at Austin
Abstract
Modern video encoding standards such as H.264 are a marvel of hidden complexity. But with hidden complexity comes hidden security risk. Decoding video in practice means in- teracting with dedicated hardware accelerators and the pro- prietary, privileged software components used to drive them. The video decoder ecosystem is obscure, opaque, diverse, highly privileged, largely untested, and highly exposed—a dangerous combination. We introduce and evaluate H26FORGE, domain-specific infrastructure for analyzing, generating, and manipulating syn- tactically correct but semantically spec-non-compliant video files. Using H26FORGE, we uncover insecurity in depth across the video decoder ecosystem, including kernel memory corruption bugs in iOS, memory corruption bugs in Firefox and VLC for Windows, and video accelerator and application processor kernel memory bugs in multiple Android devices.