A new attack has been discovered that can leak data from a CPU's internal memory or cache that affects many popular Intel processors.
The "Snoop Assisted L1 Data Sampling" attack, or Snoop for short, was first encountered by an AWS software engineer named Pawel Wieczorkiewicz.
Wieczorkiewicz immediately reported the problem to Intel, and after its own investigations into the matter, the chipmaker realized that the patches were released in August 2018 to fix the problem. The Omen Vulnerability could also apply to this new attack.
Many popular Intel processors, including those from the company's Core and Xeon lines, are vulnerable to Snoop attacks and you can refer to this list to see all the CPUs that are affected.
The new Snoop attack takes advantage of CPU mechanisms such as multiple cache levels, cache consistency, and bus snooping to filter data from the CPU core to other cores.
Fortunately, this new attack is very difficult to achieve and does not lose large amounts of data. Intel explained that Snoop attacks require conditions that are difficult to enforce in the real world, saying:
"Due to the many complex requirements that must be met to successfully carry out, Intel does not believe that Snoop-assisted L1 data sampling is a practical method in real-world environments where the operating system is trusted."
For those running high-risk systems, the company recommends that you apply the Foreshadow (L1TF) patches starting in August 2018 to protect your systems from possible Snoop attacks. Also, disabling Intel TSX (Transactional Synchronization Extensions) can greatly reduce the attack surface while making this new attack more difficult to perform.