==========================================================================
Ubuntu Security Notice USN-6797-1
May 29, 2024

intel-microcode vulnerabilities
==========================================================================

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

- Ubuntu 24.04 LTS
- Ubuntu 23.10
- Ubuntu 22.04 LTS
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS

Summary:

Several security issues were fixed in Intel Microcode.

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

Details:

It was discovered that some 3rd and 4th Generation Intel® Xeon® Processors
did not properly restrict access to certain hardware features when using
Intel® SGX or Intel® TDX. This may allow a privileged local user to
potentially further escalate their privileges on the system. This issue only
affected Ubuntu 23.10, Ubuntu 22.04 LTS, Ubuntu 20.04 LTS, Ubuntu 18.04 LTS and
Ubuntu 16.04 LTS. (CVE-2023-22655)

It was discovered that some Intel® Atom® Processors did not properly clear
register state when performing various operations. A local attacker could
use this to obtain sensitive information via a transient execution attack.
This issue only affected Ubuntu 23.10, Ubuntu 22.04 LTS, Ubuntu 20.04 LTS,
Ubuntu 18.04 LTS and Ubuntu 16.04 LTS. (CVE-2023-28746)

It was discovered that some Intel® Processors did not properly clear the
state of various hardware structures when switching execution contexts. A
local attacker could use this to access privileged information. This issue only
affected Ubuntu 23.10, Ubuntu 22.04 LTS, Ubuntu 20.04 LTS, Ubuntu 18.04 LTS and
Ubuntu 16.04 LTS. (CVE-2023-38575)

It was discovered that some Intel® Processors did not properly enforce bus
lock regulator protections. A remote attacker could use this to cause a
denial of service. This issue only affected Ubuntu 23.10, Ubuntu 22.04 LTS,
Ubuntu 20.04 LTS, Ubuntu 18.04 LTS and Ubuntu 16.04 LTS. (CVE-2023-39368)

It was discovered that some Intel® Xeon® D Processors did not properly
calculate the SGX base key when using Intel® SGX. A privileged local
attacker could use this to obtain sensitive information. This issue only
affected Ubuntu 23.10, Ubuntu 22.04 LTS, Ubuntu 20.04 LTS, Ubuntu 18.04 LTS and
Ubuntu 16.04 LTS. (CVE-2023-43490)

It was discovered that some Intel® Processors did not properly protect against
concurrent accesses. A local attacker could use this to obtain sensitive
information. (CVE-2023-45733)

It was discovered that some Intel® Processors TDX module software did not
properly validate input. A privileged local attacker could use this information
to potentially further escalate their privileges on the system.
(CVE-2023-45745, CVE-2023-47855)

It was discovered that some Intel® Core™ Ultra processors did not properly
handle particular instruction sequences. A local attacker could use this
issue to cause a denial of service. (CVE-2023-46103)

Update instructions:

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

Ubuntu 24.04 LTS
  intel-microcode                 3.20240514.0ubuntu0.24.04.1

Ubuntu 23.10
  intel-microcode                 3.20240514.0ubuntu0.23.10.1

Ubuntu 22.04 LTS
  intel-microcode                 3.20240514.0ubuntu0.22.04.1

Ubuntu 20.04 LTS
  intel-microcode                 3.20240514.0ubuntu0.20.04.1

Ubuntu 18.04 LTS
  intel-microcode                 3.20240514.0ubuntu0.18.04.1+esm1
                                  Available with Ubuntu Pro

Ubuntu 16.04 LTS
  intel-microcode                 3.20240514.0ubuntu0.16.04.1+esm1
                                  Available with Ubuntu Pro

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

References:
  https://ubuntu.com/security/notices/USN-6797-1
  CVE-2023-22655, CVE-2023-28746, CVE-2023-38575, CVE-2023-39368,
  CVE-2023-43490, CVE-2023-45733, CVE-2023-45745, CVE-2023-46103,
  CVE-2023-47855

Package Information:
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20240514.0ubuntu0.24.04.1
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20240514.0ubuntu0.23.10.1
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20240514.0ubuntu0.22.04.1
  https://launchpad.net/ubuntu/+source/intel-microcode/3.20240514.0ubuntu0.20.04.1


-- 
Alex Murray
Staff Engineer | Security Engineering
Adelaide, Australia (GMT+0930)