The short version is that every Intel platform with AMT, ISM, and SBT from Nehalem in 2008 to Kaby Lake in 2017 has a remotely exploitable security hole in the ME (Management Engine) not CPU firmware.

We knew this would happen. We knew that the Management Engine was a backdoor, and we knew it was only a matter of time before someone would figure out how to exploit it. This is exactly the reason why Libreboot exists (https://libreboot.org/faq.html#intel). And now, far from being the tinfoil hat distro that is often portrayed, it will become a bare necessity.