> I think that worrying that a self-hosted file system has a backdoor to exfiltrate data is an odd concern.

Great security teams get paid to "worry", by which I mean "make a plan" for a given attack tree.

Your use of "odd" looks like a rhetorical technique to downplay legitimate security considerations. From my point of view, you are casually waving away an essential area of security. See:

https://www.paloaltonetworks.com/cyberpedia/data-exfiltratio...

> but you should not be exposing these kinds of services to the public internet (or giving them access to the public internet), eliminating the concern that it's giving your data away.

Let's evaluate the following claim: "a "properly" isolated system would, in theory, have no risk of data exfiltration. Now we have to define what we mean. Isolated from the network? Running in a sandbox? What happens when that system can interact with a compromised system? What happens when people mess up?

From a security POV, any software could have some component that is malicious, compromised, or backdoored. It might be in the project itself or in the supply chain. And so on.

Defense in depth matters. None of the above concerns are "odd". A good security team is going to factor these in.

P.S. If you mean "low probability" then just say that.

I agree with the parent commenter. I think it's fair to be concerned with backdoors but this is a distributed file system which can be completely isolated from the outside world. If you're so worried, you could run it in an airgapped Faraday cage and do all your training in that environment. Just don't run it on any centrifuges.

I think these kinds of concerns are more valid for storage systems which serve online traffic or have some kind of connection to the outside world.