CVE-2023-31315

Publication date 12 August 2024

Last updated 30 May 2025

Ubuntu priority

Medium

Why this priority?

Cvss 3 Severity Score

7.5 · High

Score breakdown

Improper validation in a model specific register (MSR) could allow a malicious program with ring0 access to modify SMM configuration while SMI lock is enabled, potentially leading to arbitrary code execution.

From the Ubuntu Security Team

Enrique Nissim and Krzysztof Okupski discovered that some AMD processors did not properly restrict access to the System Management Mode (SMM) configuration when the SMM Lock was enabled. A privileged local attacker could possibly use this issue to further escalate their privileges and execute arbitrary code within the processor’s firmware layer.

Read the notes from the security team

Status

Package Ubuntu Release Status
amd64-microcode 24.10 oracular
Fixed 3.20240116.2+nmu1ubuntu1.1
24.04 LTS noble
Fixed 3.20231019.1ubuntu2.1
22.04 LTS jammy
Fixed 3.20191218.1ubuntu2.3
20.04 LTS focal
Fixed 3.20191218.1ubuntu1.3
18.04 LTS bionic
Fixed 3.20191021.1+really3.20181128.1~ubuntu0.18.04.1+esm3
16.04 LTS xenial
Fixed 3.20191021.1+really3.20180524.1~ubuntu0.16.04.2+esm3
14.04 LTS trusty Ignored processor not supported during LTS

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Notes

alexmurray

The affected processors were only released after the LTS period for Ubuntu 14.04 finished so there should be no affected machines running Ubuntu 14.04 hence this will not be patched in that release.

Patch details

For informational purposes only. We recommend not to cherry-pick updates. How can I get the fixes?

Package Patch details
amd64-microcode

Severity score breakdown

Parameter Value
Base score 7.5 · High
Attack vector Local
Attack complexity High
Privileges required High
User interaction None
Scope Changed
Confidentiality High
Integrity impact High
Availability impact High
Vector CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:C/C:H/I:H/A:H