[aduwah]

The whole IT industry is reliant on Linux user-based access controls, it is not a Cloudflare thing.

Also leaving a massive gap like this behind would be a mistake on multiple levels. For example, it might get combined with another exploit that can achieve unprivileged access to some piece of metal, or you can have a disgruntled employee without admin access escalating their permissions on a box they aren't supposed to see all the secrets.

[TacticalCoder]

> For example, it might get combined with another exploit that can achieve unprivileged access ...

Yeah. TFA mentions datacenters in 330 cities. That's a lot of Linux boxen. And many of those have, by definition, ports opened to the big bad Internet. These Linux servers are running services. They answer to ping, for a start. I even heard some are running DNS servers. Remote local exploits are a thing.

What does CloudFlare prefer: that when the next remote local exploit surface all their fleet is one copy.fail away from privilege escalation to root or that they get the time (seen that they obviously have quite advanced detection measures in place) to detect the intruder before it gains root everywhere?

It's Linux. It's datacenters in 330 cities. Linux powers the world and that's how things works.

I, for one, I'm glad to own CloudFlare stocks since right after the 2022 crash and, for two, I'm happy they don't let their huge fleet of Linux servers with a non-patched exploit.

[tptacek]

I'm not asking why they'd need to go threat-hunting if there was an ICMP kernel RCE in Linux. CopyFail requires someone untrusted running shell commands somewhere. Where is that exposure in their architecture?

I'm asking because I don't think they have such an exposure.

[Yoric]

At the very least, Cloudflare hosts web workers, which let a customer execute more-or-less arbitrary wasm code on their servers. If there's an exploit that lets you escape the wasm sandbox, copy.fail can be chained into (afaiu) an exploit against the Linux host. That's a pretty big risk.

Also, Cloudflare hosts some AI services, so it's possible that some consumers are running Python code in their containers, without the wasm sandbox.

[tptacek]

If there's a direct link from Cloudflare workers / WASM to uid=nobody execve or arbitrary syscalls on their hosts, they're already fucked, so I don't think that's true.

[HDBaseT]

I don't understand your point.

You seem so pressed on the fact "why would they even patch this!!!", maybe because its best practice to patch things? You never known what things could be chained together, so you might as well patch this, given its so obviously bad.

[js2]

That's a straw man and not what he asked. Literally, he asked: "why they would have been vulnerable to CopyFail?"

I've been a sysadmin/programmer since the mid-90s. Local root exploits are a dime a dozen. If your infrastructure relies upon the tenuous difference between root and non-root accounts, you've already lost. Cloudflare isn't an ISP handing out shell accounts on Unix machines.

So again, yes, of course you should patch your Linux machines. Defense in depth and all that. But the question remains: "why Cloudflare would have been vulnerable to CopyFail?" (in anything but an academic sense). Because I do not believe that they can possibly be relying on the difference between root and non-root account.