zlacker

>>zdw+(OP)
"If a potential attacker already has administrative access to the BMC..."

Then you've already lost.

The BMC needs to be ideally on a physically isolated network, or at least a separate one that has no route from the outside nor on the machine itself.

>>SoftTa+K5b
That’s a cop-out. It should be the case that even administrator access should not be abusable to implant permanent backdoors.

Anything that makes privileges escalation exploits more damaging is a real problem. I’m getting tired of how these are being dismissed as if admin access should mean that you can ignore any security issues. There are things that even admin accounts should not be able to change at the hardware level, or if they can they must be reversible in the future by another user with admin access.

> The BMC needs to be ideally on a physically isolated network, or at least a separate one that has no route from the outside nor on the machine itself.

This is good practice but it shouldn’t excuse poor security at the hardware level.

Supermicro motherboards also commonly default to having a feature that bonds the BMC network interface to one of the main NICs if you don’t plug a cable into the BMC interface. It’s common for people to be surprised that their BMC is exposed on their main network because they didn’t plug in a cable on the BMC NIC port at all.

>>Aurorn+S7b
It should be the case that even administrator access should not be abusable

If administrator access is equivalent to ownership, then I strongly disagree.

>>userbi+Dvb
As an administrator, you generally expect to be able to change your mind at some point.

Flashing data? Fine.

Permanent? Not so much.

>>shakna+XHb
This logic doesn't hold. If I choose to dban or degauss something, I don't expect I should be able to recover it later. Admins absolutely have the option to make irreversible changes, and do this quite often.

>>ang_ci+M5c
What's irreversible about dban?

If you are magnetically destroying hard drives as part of decommissioning, that's not really the same thing. You're not using admin access to do it, and you're not making a change that permanently applies to all future use of the device (because there is no future use).

>>Dylan1+Iic
> What's irreversible about dban?

If you do it right, the data erasure.

>>ang_ci+VBi
Yes but we were talking about hardware level changes and the person you responded to specifically said flashing was okay. So I thought you had something relevant to that in mind.

Anyone can delete a file. Nobody wants to ban deleting files.