New #GoFetch attack on Apple Silicon CPUs can steal #crypto keys.
A new side-channel attack named "GoFetch" has been discovered, impacting Apple M1, M2, and M3 processors. This attack targets constant-time cryptographic implementations using data memory-dependent prefetchers (DMPs) found in modern Apple CPUs, allowing attackers to steal secret cryptographic keys from the CPU's cache. GoFetch was developed by a team of researchers who reported their findings to Apple in December 2023. Since this is a hardware-based vulnerability, impacted CPUs cannot be fixed. While software fixes could mitigate the flaw, they would degrade cryptographic performance. The attack leverages flaws in Apple's implementation of the DMP system, violating constant-time programming principles. Owners of affected Apple devices are advised to practice safe computing habits, including regular updates and cautious software installation. While Apple may introduce mitigations through software updates, they could impact performance. Disabling DMP may be an option for some CPUs but not for M1 and M2. The attack can be executed remotely, making it a serious concern for users. Apple has yet to provide further comments on this issue.