This blog post also explains the sandbox escape that was used to attack coinbase in 2019. Public exploits and write-ups exist, but this blog post focuses on the techniques to find these bugs:
The APIs that Firefox uses to send messages across processes
How to fake these IPC messages, which essentially helps simulating a compromised child process and might be useful in finding additional sandbox escapes
How to enable browser-process debugging and step through JavaScript code in parent and child process using normal Firefox DevTools.
This blog post also explains the sandbox escape that was used to attack coinbase in 2019. Public exploits and write-ups exist, but this blog post focuses on the techniques to find these bugs: