An Intel Microcode security update has been released for Ubuntu Linux 18.04 LTS, 20.04 LTS, 20.10, and 21.04.

USN-4628-3: Intel Microcode vulnerabilities

=========================================================================
Ubuntu Security Notice USN-4628-3
May 17, 2021

intel-microcode vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 21.04
- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

Several security issues were fixed in Intel Microcode.

Software Description:
- intel-microcode: Processor microcode for Intel CPUs

Details:

USN-4628-1 provided updated Intel Processor Microcode for various processor
types. This update provides the corresponding updates for some additional
processor types.

Original advisory details:

Moritz Lipp, Michael Schwarz, Andreas Kogler, David Oswald, Catherine
Easdon, Claudio Canella, and Daniel Gruss discovered that the Intel
Running
Average Power Limit (RAPL) feature of some Intel processors allowed a
side-
channel attack based on power consumption measurements. A local attacker
could possibly use this to expose sensitive information. (CVE-2020-8695)

Ezra Caltum, Joseph Nuzman, Nir Shildan and Ofir Joseff discovered that
some Intel(R) Processors did not properly remove sensitive information
before storage or transfer in some situations. A local attacker could
possibly use this to expose sensitive information. (CVE-2020-8696)

Ezra Caltum, Joseph Nuzman, Nir Shildan and Ofir Joseff discovered that
some Intel(R) Processors did not properly isolate shared resources in some
situations. A local attacker could possibly use this to expose sensitive
information. (CVE-2020-8698)

Update instructions:

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

Ubuntu 21.04:
intel-microcode 3.20210216.0ubuntu0.21.04.1

Ubuntu 20.10:
intel-microcode 3.20210216.0ubuntu0.20.10.1

Ubuntu 20.04 LTS:
intel-microcode 3.20210216.0ubuntu0.20.04.1

Ubuntu 18.04 LTS:
intel-microcode 3.20210216.0ubuntu0.18.04.1

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

References:
  https://ubuntu.com/security/notices/USN-4628-3
  https://ubuntu.com/security/notices/USN-4628-1
CVE-2020-8695, CVE-2020-8696, CVE-2020-8698

Package Information:
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20210216.0ubuntu0.21.04.1
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20210216.0ubuntu0.20.10.1
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20210216.0ubuntu0.20.04.1
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20210216.0ubuntu0.18.04.1