Another SMT side-channel attack has been discovered, allowing the extraction of OpenSSL keys from Intel Skylake and Kaby Lake processors. Researchers speculate that Ryzen might also be affected, but have not confirmed.
“This is the main reason we released the exploit – to show how reproducible it is,” Brumley told us, “and help to kill off the SMT trend in chips. Security and SMT are mutually exclusive concepts,” he added. “I hope our work encourages users to disable SMT in the BIOS or choose to spend their money on architectures not featuring SMT.”