USN-3531-2: Intel Microcode regression

Ubuntu Security Notice USN-3531-2

22nd January, 2018

intel-microcode regression

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 17.10
  • Ubuntu 16.04 LTS
  • Ubuntu 14.04 LTS

Summary

USN-3531-1 introduced regressions in intel-microcode.

Software description

  • intel-microcode - Processor microcode for Intel CPUs

Details

USN-3531-1 updated Intel microcode to the 20180108 release. Regressions
were discovered in the microcode updates which could cause system
instability on certain hardware platforms. At the request of Intel, we have
reverted to the previous packaged microcode version, the 20170707 release.

Original advisory details:

It was discovered that microprocessors utilizing speculative execution
and branch prediction may allow unauthorized memory reads via sidechannel
attacks. This flaw is known as Spectre. A local attacker could use this to
expose sensitive information, including kernel memory. (CVE-2017-5715)

This update provides the microcode updates required for the corresponding
Linux kernel updates.

Update instructions

The problem can be corrected by updating your system to the following package version:

Ubuntu 17.10:
intel-microcode 3.20180108.0+really20170707ubuntu17.10.1
Ubuntu 16.04 LTS:
intel-microcode 3.20180108.0+really20170707ubuntu16.04.1
Ubuntu 14.04 LTS:
intel-microcode 3.20180108.0+really20170707ubuntu14.04.1

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

After a standard system update you need to reboot your computer to make
all the necessary changes.

References

LP: 1742933