Apple M-Series CPUs Affected by "GoFetch" Unpatchable Cryptographic Vulnerability

A team of academic researchers has uncovered a critical vulnerability in Apple M-series CPUs targeting data memory-dependent prefetcher (DMP) that could allow attackers to extract secret encryption keys from Macs. The flaw, called GoFetch, is based on the microarchitecture design of the Apple Silicon, which means that it cannot be directly patched and poses a significant risk to users' data security. The vulnerability affects all Apple devices powered by M-series chips, including the popular M1 and M2 generations. The M3 generation can turn a special bit off to disable DMP, potentially hindering performance. The DMP, designed to optimize performance by preemptively loading data that appears to be a pointer, violates a fundamental requirement of constant-time programming by mixing data and memory access patterns. This creates an exploitable side channel that attackers can leverage to extract secret keys.