CVE-2023-31315

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

Show unmaintained releases

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 Ubuntu Pro
	16.04 LTS xenial	Fixed 3.20191021.1+really3.20180524.1~ubuntu0.16.04.2+esm3 Ubuntu Pro
	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	Upstream: https://git.kernel.org/pub/scm/linux/kernel/git/firmware/linux-firmware.git/commit?id=091bd5adf19c7ab01214c64689952acb4833b21d

References

Related Ubuntu Security Notices (USN)

USN-7077-1
AMD Microcode vulnerability
21 October 2024