Intel is the benchmark brand in the computer sector in Spain; If you buy a new PC, it is most likely that it will mount an Intel model, although AMD is gaining ground little by little with its new Ryzen.
Therefore, any problem that affects this brand has the potential to cause a disaster for a large part of computer users; This is what happened, for example, with the discovery of Specter and Meltdown, two vulnerabilities that took advantage of processor design flaws.
Now, researchers at the cybersecurity company Positive Technologies have gone further; for the first time, they have managed to obtain a piece of code absolutely vital to the security of the system.
Secret Password
Specifically, the researchers have managed to extract the secret key used in some Intel processors to encrypt the code that is executed to install updates; this "microcode" usually includes fixes to "bugs" and vulnerabilities.
For example, with the aforementioned Specter and Meltdown, Intel released updates that mitigated these issues (although they couldn't fix them entirely). The reason this is so important is because this code does not run at the operating system level; neither Windows nor macOS nor any other system can even know that it is running.
And that is why accessing this run level can be very dangerous, as it would allow an attacker to execute code capable of bypassing all security measures. Researchers cannot say at the moment to what extent their discovery will have an impact on user safety; They have only shared what they have been able to do.
Today we're[+@_markel___ and @_Dmit]disclosing the technique allowing to modify #Intel #Microcode on the fly! For the first time you have the ability to intercept control flow at such a low level. We've developed the microcode patch that changes the processor model string as PoC pic.twitter.com/4zdBGS51GR
— Maxim Goryachy (@h0t_max) October 13, 2020
With access to this secret key, you can decrypt the microcode that runs to update some Intel processors, understand how it works and create own code, such as software spyware or malware running on the system without being detected. In the words of the researchers, the attacker "would have the keys to the kingdom", and would have very few limits to what he could do with them.
Intel Processors Affected
If we have an Intel processor, there are two consolations. To begin with, it is impossible to carry out this type of attack without physical access to the computer; the attacker would have to steal our laptop or use it for a time without us noticing.
Once the attack was made, it would be impossible to detect it. But without a doubt, the best we can say is that, for now, this attack is only possible on some Intel processors, and most of them are old; The researchers have only managed to affect the processors of the Goldmont architecture, launched in 2016 for low-cost models.
None of the affected models would be a Core; all are Pentium, Celeron or Atom. The desktop processors in this range are:
Intel Pentium J4205
Intel Celeron J3455
Intel Celeron J3355
The rest of the affected models are server or mobile processors. It is not clear if this research can help extract the encryption key on other Intel processors; For now, we can say that this discovery is historic for having been able to achieve something that had never been achieved.
