In the recommended OS model for Mill these sorts of exploits are impossible. Security on the Mill is the subject of a future talk, but briefly: the Mill is intended to use a nano-kernel style OS structure. There is no “kernel mode” or “user mode”, no supervisor, and no privileged operations; “stack cracking” is impossible. Where architecture comes in: there is no performance penalty for a secure system on the Mill.
IMO, putting a user-reachable JIT where it can access memory that it is not intended to use, all in the name of performance, is appalling. The inevitable result is well deserved.
There is no complete technological solution to security; all precautions fall before blackmail, cute agents, and other social penetrations. However, admitting that is not the same as posting a large “enter here” sign on an unlocked door.