Augury vulnerability discovered in Apple silicon and mobile chips


Augury is unique in that it can leak data that neither the core nor any instructions have read yet. Many Spectre countermeasures that work by watching what data the core and instructions access are rendered useless.

The usage of a Data Memory-Dependent Prefetcher (DMP) in Apple silicon, which is an optimization that takes into consideration the content of earlier memory prefetches, gives the device its augury. This method gives an indication of the contents of the memory, allowing them to be leaked. Read More…