Sorry, I’m not sure, this stuff largely goes over my head. I just understand the basics.

If I had to guess, I wouldn’t be surprised if a different exploit is found that bypasses the bios setting to compliment this one.

Precisely so. At least for the Intel machines that have IME features. So all the enterprise, data-center boxes but not every laptop.

Edit: I read some more. It looks like this is going beyond what I thought and affects way more machines.

Reading http://www2.lauterbach.com/pdf/dci_intel_user.pdf, there are two ways to debug over that connector; one using the USB protocol and the other using a proprietary protocol. If this uses the latter, that device, technically, wouldn’t have to be a USB device (but of course, it could still masquerade as one)

That PDF also says your BIOS must support this kind of debugging, and, for the ‘OOB’ protocol, your hardware must support it. So, your BIOS may be configurable to make this attack impossible, and your hardware may already be protected against it.

You're talking about AMT (which runs on the Intel ME - Management Engine). The ME itself, however, is on every CPU (running Minix on Skylake and later CPUs, ThreadX on earlier models), because one of the responsibilities of the ME, apart from being a backdoor, is to manage the CPU: power it on, handle power signals, etc. The CPU wouldn't run without the ME, so it's necessary that it's on all CPUs.

Intels own guidelines say that DCI should be disabled by default, although on some systems that was not true[1], afaik (would like to be corrected if wrong) this does not impact vast majority of systems. This seems more like a frontdoor that is supposed to be locked tight rather than an backdoor. The bugs that actually enable DCI could be more likely candidates to be considered backdoors.

[1] https://security-center.intel.com/advisory.aspx?intelid=INTE...