Intel 20230808 Microcode Published For DOWNFALL, Other Security & Functional Issues

In addition to the Linux kernel patches for GDS/Downfall for reporting the mitigated state and handling around Intel's latest speculative execution vulnerability, the updated CPU microcode has now been published on GitHub. In addition to having the Downfall mitigations for Skylake through Icelake/Tigerlake, there are also other security updates and functional issues resolved by this Intel 20230808 CPU microcode release.

First and foremost this updated Intel CPU microcode has the mitigations needed for the rather nasty Downfall security vulnerability that was disclosed this Patch Tuesday. I already have benchmarks in the works and initial results should be out in a matter of hours.

In addition to Downfall (INTEL-SA-00828), there is also a fix in this microcode for INTEL-SA-00836 that affects 3rd Gen Xeon Scalable processors with an information disclosure issue. That carries a medium CVSS rating and requires local access with a privileged user. There is also INTEL-SA-00837 as a security vulnerability rated with a 7.2 "High" CVSS score around Intel SGX that could allow escalation of privilege.

In addition to the three security fixes, there are also unspecified updates for functional issues. Functional issues have been resolved from 13th Gen Core "Raptor Lake" and older as well as 3rd Gen Xeon Scalable and older. In the end with today's microcode update are revisions for all platforms from Skylake and newer