Or the reason to run Firefox in a FreeBSD jail to get server-grade security. But the question is can an attacker get access to the Firefox profile data? Because you cannot block that from Firefox, obviously.
Not sure how that partitions the files on disk though, would probably need some code changes to work with some kind of firejail setup.
This is seamless on Qubes OS: You just click a link and a new empty VM with Firefox opens. You close the browser, and the VM is destroyed. Can't recommend it enough.
[0] https://forum.qubes-os.org/t/qsb-116-multiple-xen-issues-xsa...
You could also use a VM on FreeBSD too, but I would argue that it's very inefficient to boot up a VM for each application instance. A container/jail is virtually the same as a VM, except a VM uses your host's kernel. And kernels are probably the least of worries in terms of security for apps.
> but I would argue that it's very inefficient to boot up a VM for each application instance
https://doc.qubes-os.org/en/latest/introduction/faq.html#doe...
> A container/jail is virtually the same as a VM
No, it's not, https://hn.algolia.com/?q=container+escape
Also Qubes doesn't just use VMs but enforces virtualization with hardware (VT-d).