[rs_rs_rs_rs_rs]

>it’s time everyone considers OpenBSD

https://x.com/ortegaalfredo/status/2055362910415671459

When your super secure feature gets defeated by a symlink maybe it's not really time to consider it...

Sure, things are not better in the linux world but at least there's more eyes to fix issues there just because of the market share.

[ori_b]

Note that this specific symlink was special cased because sandboxed programs still need to access timezones. Also note that you would need to be root to create that special cased symlink. It's embarrassing, but less catastrophic than it looks at first glance.

Running security-critical code as root is still a bad idea.

[866-RON-0-FEZ]

Your "evidence" for him to reconsider is a sandbox "bypass" that requires you to be root to set up the environment?

For my next trick I will demonstrate how to break into my own house to open the blinds by using my keys.

Security researcher theatrics will never not be funny.

[gjm11]

Maybe I'm misunderstanding the video, but it looks to me as if the situation is:

You are root inside a sandbox. As root-in-the-sandbox, you create a symlink and this gives you the ability to escape the sandbox.

(Whether this is interesting or not depends on whether anyone actually tries to use the sandbox facility in such a way as to give root-in-the-sandbox privileges to untrusted people or code. I don't know enough about OpenBSD to answer that.)

[ori_b]

OpenBSD doesn't do different user accounts inside vs outside sandboxes; if you're root in the sandbox, you're root on the system.

[anthk]

Also I tried the Dirtyfrag exploit under Bubblewrap for GNU/Linux. It lasted, but finally I got root with a simple 'su'.

[wahern]

unveil was designed and intended to effectively sandbox root when combined with sufficiently strict pledge permissions. I don't think this exploit would have effected any existing OpenBSD services, but sometimes services need to keep around processes with higher privileges than the network-facing process, yet you still want to sandbox them as much as possible. For example, sshd uses a special auth process, and that process needs higher privileges to be able to access the password database. On OpenBSD this auth process doesn't need root, but there may be similar cases where you want to use unveil with a root process for defense-in-depth. Suffice it to say, it would be foolish to only use unveil with such processes.

The bug here actually involved the intersection of unveil and pledge. IIUC, it was more a pledge bug that accidentally allowed bypassing unveil checks.

[866-RON-0-FEZ]

So what? You're still root. You're relying on a sandbox to plug a few voids while you still effectively held keys to the kingdom before said voids were plugged.

I hear this excuse daily from developers who insist on running all their docker containers as root "because we have to".

If you're relying on a sandbox as your first line of defense you've already lost the war.

[MarsIronPI]

I think the idea is to not run programs as root in the sandbox.

[SmirkingRevenge]

The parents tone wasn't warranted, but bugs like this could be more serious if combined with privilege escalation bugs in the sandbox.

Ideally, sandboxes should be like Vegas - what happens in the sandbox stays in the sandbox.

(I'm just speaking hypothetically here, I'm not knowledgeable about OpenBSD or it's sandboxes)

[rs_rs_rs_rs_rs]

>Your "evidence" for him to reconsider is a sandbox "bypass" that requires you to be root to set up the environment

Can you help figure out where does it say unveil does not really work when root is involved?

[866-RON-0-FEZ]

You left a snarky comment, then paraded around a positively lame example as some sort of trophy.

Here's what I can figure out: you need root to set up the environment just so. It's a don't-care. The end.

[3form]

So, a break out of chroot in a chroot jailed app would be a non-issue because I need root to set it up?

[yjftsjthsd-h]

If you need root to set up the escape, then yes that is relatively uninteresting. Like, we know chroot can't contain root.

[3form]

Thanks. It was not evident from the example whether root inside of the sandbox is necessary - I assumed creating arbitrary symlinks doesn't require any particular capabilities, and there's nothing special about the locations.

Though it's not clear to me now:

- why was this patched then?

- is the point about root that non-root wouldn't have access to passwd anyway?

[rs_rs_rs_rs_rs]

>Here's what I can figure out: you need root to set up the environment just so.

I guess you just don't understand what unveil does.

[866-RON-0-FEZ]

Your arrogance is continued proof you could never comprehend the work that goes into building, releasing, and maintaining an entire OS, and your contributions will forever be limited to snarky negativity on message boards.

[rs_rs_rs_rs_rs]

Anything on unveil and not about me?