The Security On Older Intel BIOS Firmware Is A Bit Floppy; Get Patching!
Atoms, And Celerons, And Pentiums, Oh My
The good news is that there are patches being provided for most of the affected processors, but unfortunately some older processor families such as Kaby Lake are likely to remain vulnerable as it has been a while since motherboard vendors put out a new Z270 BIOS. It is unlikely they will after this, and the same may hold true for Z390 boards as well. That doesn’t even delve into the embedded products which are also vulnerable.
Two of the three Intel BIOS firmware flaws, dubbed CVE-2021-0157 and CVE-2021-0158, could lead to escalation of privilege on the machine if someone can gain physical access to it. Generally that means the flaw is considered less severe than one which can be triggered remotely, however in this case the attack targets the SMM code stored in SMRAM on the motherboard. If the attack is successful the attacker could modify that code to install BIOS level hacks which are almost impossible to detect as SMRAM is inaccessible by your OS or any applications including virus scanners and and can be quite troublesome to remove if you do find evidence of it.
The third Intel BIOS firmware flaw will get you where the rubber hits the road, as one of the vulnerable chips is the Atom E3900 embedded processors which is found in more than 30 car models, including Tesla’s Model 3 if the rumours are correct. That Atom, as well as other embedded Pentium and Celeron models are found in IoT devices and you will have to depend on the manufacturer providing updates for you to install. The track record for IoT companies doing so in the past leaves a lot to be desired, and not many people are familiar with how to update the firmware on their cars.
That third vulnerability could allow an attacker to extract the Intel CSME firmware key or the root encryption key that secures Intel Platform Trust Technology and Enhanced Privacy ID, letting them install their own updates which would pass any and all attempts to find it as their updates would be every bit as trusted as the original firmware.
The former concerns the insufficient control flow management in the BIOS firmware for some Intel processors, while the latter relies on the improper input validation on the same component.