USN-4182-1 provided updated Intel Processor Microcode. A regression was discovered that caused some Skylake processors to hang after a warm reboot. This update reverts the microcode for that specific processor family.
We apologize for the inconvenience.
Original advisory details:
Stephan van Schaik, Alyssa Milburn, Sebastian Österlund, Pietro Frigo, Kaveh Razavi, Herbert Bos, Cristiano Giuffrida, Giorgi Maisuradze, Moritz Lipp, Michael Schwarz, Daniel Gruss, and Jo Van Bulck discovered that Intel processors using Transactional Synchronization Extensions (TSX) could expose memory contents previously stored in microarchitectural buffers to a malicious process that is executing on the same CPU core. A local attacker could use this to expose sensitive information. (CVE-2019-11135)
It was discovered that certain Intel Xeon processors did not properly restrict access to a voltage modulation interface. A local privileged attacker could use this to cause a denial of service (system crash). (CVE-2019-11139)
CVEs contained in this USN include: CVE-2019-11135, CVE-2019-11139
Severity is high unless otherwise noted.
Users of affected products are strongly encouraged to follow one of the mitigations below: