Hardware-level vulnerability found in Apple Silicon CPUs

A side-channel vulnerability has been found in the architecture of Apple Silicon processors that gives malicious apps the ability to extract cryptographic keys from memory that should be off limits. Dubbed GoFetch by the team that discovered it, the issue stems from how processors equipped with data memory-dependent prefetchers (DMPs) - eg, Arm-compatible Apple Silicon chips, and 13th generation and newer Intel architectures - can end up revealing sensitive information to malware running on a device. For decades a lot of processors have typically used some kind of prefetching to boost their performance: These usually work by predicting what data the currently running program will need next from, say, system memory and automatically bringing that information into a cache within the processor from DRAM so it's ready for near-immediate use. The location of the data to prefetch could be predicted by noticing that a CPU core is accessing information in a certain pattern and then following that pattern ahead of execution. DMPs try to be a bit smarter by predicting what will be fetched next from the contents of memory. For instance, if it looks like the processor is preparing to fetch some data from a location based on what looks like a memory address at another location – think linked lists and the like in which one block of data has a pointer to another – the DMP may begin bringing into the cache that next data. But that isn't without its problems: A vulnerable DMP can be manipula...