==========================================================================
Ubuntu Security Notice USN-5535-1
July 28, 2022

Intel Microcode vulnerabilities
==========================================================================

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

- Ubuntu 16.04 ESM

Summary:

Several security issues were fixed in Intel Microcode.

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

Details:

Joseph Nuzman discovered that some Intel processors did not properly
initialise shared resources. A local attacker could use this to obtain
sensitive information. (CVE-2021-0145)

Mark Ermolov, Dmitry Sklyarov and Maxim Goryachy discovered that some Intel
processors did not prevent test and debug logic from being activated at
runtime. A local attacker could use this to escalate
privileges. (CVE-2021-0146)

It was discovered that some Intel processors did not implement sufficient
control flow management. A local attacker could use this to cause a denial
of service (system crash). (CVE-2021-0127)

It was discovered that some Intel processors did not completely perform
cleanup actions on multi-core shared buffers. A local attacker could
possibly use this to expose sensitive information. (CVE-2022-21123,
CVE-2022-21127)

It was discovered that some Intel processors did not completely perform
cleanup actions on microarchitectural fill buffers. A local attacker could
possibly use this to expose sensitive information. (CVE-2022-21125)

Alysa Milburn, Jason Brandt, Avishai Redelman and Nir Lavi discovered that
some Intel processors improperly optimised security-critical code. A local
attacker could possibly use this to expose sensitive
information. (CVE-2022-21151)

It was discovered that some Intel processors did not properly perform
cleanup during specific special register write operations. A local attacker
could possibly use this to expose sensitive information. (CVE-2022-21166)

It was discovered that some Intel processors did not properly restrict
access in some situations. A local attacker could use this to obtain
sensitive information. (CVE-2021-33117)

Brandon Miller discovered that some Intel processors did not properly
restrict access in some situations. A local attacker could use this to
obtain sensitive information or a remote attacker could use this to
cause a denial of service (system crash). (CVE-2021-33120)

Update instructions:

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

Ubuntu 16.04 ESM:
intel-microcode 3.20220510.0ubuntu0.16.04.1+esm1

In general, a standard system update will make all the necessary changes.

References:
https://ubuntu.com/security/notices/USN-5535-1
CVE-2021-0127, CVE-2021-0145, CVE-2021-0146, CVE-2021-33117,
CVE-2021-33120, CVE-2022-21123, CVE-2022-21125, CVE-2022-21127,
CVE-2022-21151, CVE-2022-21166