SGAxe attack builds on CacheOut speculative execution attack to steal SGX data. CrossTalk attack takes advantage of a “staging” buffer that’s readable across all CPU cores to mount transient execution attacks and extract the private key of a secure enclave running on a separate CPU. Intel issued fixes for CacheOut back in January via a microcode update to OEM vendors and subsequently via BIOS updates to end-users. Intel will also perform a Trusted Compute Base (TCB) recovery to invalidate all previously signed attestation keys.
Source: https://thehackernews.com/2020/06/intel-sgaxe-crosstalk-attacks.html