Virtually Unlimited Memory: Escaping the Chrome Sandbox

After discovering a collection of possible sandbox escape vulnerabilities in Chrome, it seemed worthwhile to exploit one of these issues as a full-chain exploit together with a renderer vulnerability to get a better understanding of the mechanics required for a modern Chrome exploit. Considering the available bugs, the most likely appeared to be issue 1755, a use-after-free with parallels to classic Javascript engine callback bugs. This is a good candidate because of the high level of control the attacker has both over the lifetime of the free’d object, and over the timing of the later use of the object.