An Intel Microcode security update has been released for Ubuntu Linux 18.04 LTS, 20.04 LTS, and 22.04 LTS.

USN-5612-1: Intel Microcode vulnerability

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Ubuntu Security Notice USN-5612-1
September 15, 2022

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

- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

A security issue was fixed in Intel Microcode.

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

Details:

Pietro Borrello, Andreas Kogler, Martin Schwarzl, Daniel Gruss, Michael
Schwarz and Moritz Lipp discovered that some Intel processors did not
properly clear data between subsequent xAPIC MMIO reads. This could allow a
local attacker to compromise SGX enclaves.

Update instructions:

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

Ubuntu 22.04 LTS:
intel-microcode 3.20220809.0ubuntu0.22.04.1

Ubuntu 20.04 LTS:
intel-microcode 3.20220809.0ubuntu0.20.04.1

Ubuntu 18.04 LTS:
intel-microcode 3.20220809.0ubuntu0.18.04.1

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

References:
  https://ubuntu.com/security/notices/USN-5612-1
CVE-2022-21233

Package Information:
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20220809.0ubuntu0.22.04.1
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20220809.0ubuntu0.20.04.1
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20220809.0ubuntu0.18.04.1