This document describes exploiting a use-after-free vulnerability called "Hearthstone" in VMware Workstation to escape from a virtual machine. It begins with background on VMware RPC and the fuzzing framework used. It then explains the Hearthstone vulnerability, how it allows information leakage, and how that leakage can be used to conduct an out-of-bounds write to achieve code execution on the host system. The presentation concludes with a demonstration of the exploitation process and takes questions.