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Many years ago, OpenBSD's Theo De Raadt made a sneer at virtualization, saying something the lines of "they can't even build a secure system, let alone a secure virtualized system". I can't remember who he was referring to specifically, but we've certainly been seeing a lot of similar vulnerabilities.





Here's the full Theo de Raadt quote from 2007 [1]:

"""> Virtualization seems to have a lot of security benefits.

You've been smoking something really mind altering, and I think you should share it.

x86 virtualization is about basically placing another nearly full kernel, full of new bugs, on top of a nasty x86 architecture which barely has correct page protection. Then running your operating system on the other side of this brand new pile of shit.

You are absolutely deluded, if not stupid, if you think that a worldwide collection of software engineers who can't write operating systems or applications without security holes, can then turn around and suddenly write virtualization layers without security holes.

You've seen something on the shelf, and it has all sorts of pretty colours, and you've bought it.

That's all x86 virtualization is. """

[1] https://marc.info/?l=openbsd-misc&m=119318909016582


I feel like people with these sorts of hardline views on security, might just be so concerned with safety that their argument misses the whole opportunity cost of not being 100% safe in our usage of technology. If we needed to make sure everything was safe and perfectly secure, the world would have missed out on a lot of innovative software. Tough thing to contend with is that the security people are hardly ever wrong.

>hardline views on security

The only hardline view on security you'll encounter in the wild is "security is practical in our computational environments"[1]. Only half-joking here.

My reading of Theo's quote is merely "the combination of x86/IA32/AMD64 and virtualization gives little to no factual security benefits, and plenty of pitfals".

I don't see Theo as being a hardliner about security, just meticulous about good engineering practices - as per OpenBSD's usual standards - and facing the problems & risks as they are.

[1] examples: "Rust/Java gives you security", "shortlisting the only allowed actions by end-user application gives you security", "hardcore firewalls give you security", "virtualization gives you security", "advanced architectures like Burroughs' give you security".


Except that's objectively wrong - x86 virtualization breakouts have been extremely rare in practice, and fixable till recently.

The new class of attacks we now see target any type of shared code execution environment. OpenBSD is as vulnerable to this as anything else.


OpenBSD disables hyperthreading, doesn't it? That's a smart defense against at least one of today's attacks. Doesn't help if you're a VM guest, but does if you're the host.

there's a foreshadow-ng variant specifically for vms, and it's arguably the worst

> examples: "Rust/Java gives you security"

Reminds me a friend who worked on Javascript in the early days said it was the only thing that had any hope of providing minimal security at the time. Because Windows 3.1 and 95 +0x86 was a security trashfire.


I believe "they" were all the people poking the project asking when were they going to support virtual X and virtual Y. He basically stated it would never happen on OpenBSD[1] but here we are with [2] (vmm/vmd/vmctl).

[1] http://www.tylerkrpata.com/2007/10/theo-de-raadt-on-x86-virt...

[2] https://www.openbsd.org/faq/faq16.html

[1] probably isn't the best source out there, I was in a bit of a rush to find it but that is indeed the quote! Gotta either love or hate Theo I guess!


Would be cool to see a source for that one. Theo de Raadt is a hardliner whom I don't always agree with, but I'd like to know how visionary he actually was in this case (quite a bit by the looks of it).

I'm not a security person but I wanna practice trying to sum up his points:

1. There's no way in hell that a bunch of VMs running on one physical server is more secure than a bunch of different physical servers each running an OS. If there were architectural hooks for those VMs to provide additional security beyond what the host OS provides, then an OS like OpenBSD would already be making use of it.

2. Running a bunch of VMs on a single physical machine is certainly cheaper.

3. People who are in favor of the cost-cutting are claiming that there's a security benefit to sell more stuff.

Am I right?

If so, how does that stance jibe with the research that Qubes is based on?


I think the argument VM-sellers make is that it's more secure than running a bunch of colocated code on the same machine without VMs, not that it's more secure than distinct physical systems.

That is their claim. Theo is pointing out that the security is an illusion. Either the OS is secure and so you may as well just run everything in the OS without the VM in the way (ignoring issues of different operating system), or the OS is not secure and now you have to hope the VM is secure because otherwise you just exploit your VM to get out of it and then exploit the OS. The second level attack is more difficult, but that is all.

Almost right, except one thing: I think Theo de Raadt wrongly did not acknowledge the valid point of his opponent: in practice, separating applications into virtual machines does have some security benefits, when compared to running them on single OS.

I think security guarranties are better if you follow practices of a little selfcentered project such as OpenBSD (run only trusted code) than if you follow practices of QubesOS (running whatever untrusted code you desire in Xen domains and relying on VM separation).





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