AMD CPU Vulnerability Discovered for Dreadful Side Channel Attacks

A CPU generally has plenty of software running at once and plays a major role in system security. Recently, research has discovered that there is particular AMD CPU vulnerability which allows data to be shared between programs running on the same core.

Referred to as the “Take A Way” exploit, a hacker could begin their attack by picking an address corresponding with the target’s data address. Afterwards, they then access the data stored in their version of the address, which will create a link based on the address within the cache and the way predictor. The route that the CPU takes to access that address next time is guaranteed to be quick but if its triggered a third time, the CPU will get to it slowly.

All the hacker has to do is bring up the address at regular intervals. If it comes quick, then the victim has not accessed it during the interval but if it takes a while, then it has been accessed. This will serve as an important indicator for when victims access data stored within the CPU without knowing where the data is and without the need to share memory with the victim.

Key Takeaway from the research paper on the AMD CPU vulnerability

The key takeaway of this paper is that AMD’s cache way predictors leak secret information.

To demonstrate how it can be bad, the researchers paired the AMD CPU vulnerability with existing attack patterns and weaknesses. They constructed a covert channel between two software that aren’t meant to communicate together. They could break address space layout randomization (ASLR), a key step in accessing CPU memory. As a result, they can leak kernel data and even crack AES encryption keys.

It’s worth noting that the AMD CPU vulnerability isn’t an easy one to take advantage of. It involves a combination of exploits working in complex ways, but it is still possible. It is said to affect some older Athlon, Ryzen, and Threadripper CPUs. AMD has yet to respond to the allegations or mentioned any updates to fix the exploit at the time of this writing.

The researchers themselves have noted that it shouldn’t be too difficult to come up with a solution for the issue. It was also noted that the Austrian team behind the research reported their findings on August 2019. We will be reporting more on this when information becomes available so stay tuned.

Are you worried about the exploit? Join the discussion right below here:

Pokdepinion: Someone at Intel is probably going like “Ha, they finally have a problem with a CPU”.