CVE-2023-20569

Published: 8 August 2023

A side channel vulnerability on some of the AMD CPUs may allow an attacker to influence the return address prediction. This may result in speculative execution at an attacker-controlled address, potentially leading to information disclosure.

From the Ubuntu Security Team

Daniël Trujillo, Johannes Wikner, and Kaveh Razavi discovered that some AMD processors utilising speculative execution and branch prediction may allow unauthorised memory reads via a speculative side-channel attack. A local attacker could use this to expose sensitive information, including kernel memory.

Notes

Priority reason:
Unprivileged local attackers may use this vulnerability to extract confidential data.

The listed microcode revisions for 3rd Gen AMD EPYC processors in
AMD-SB-7005 were provided to the upstream linux-firmware repo in commit
b250b32ab1d044953af2dc5e790819a7703b7ee6 whilst the 4th Gen microcode was
provided in commit f2eb058afc57348cde66852272d6bf11da1eef8f.
This is not planned to be fixed for the amd64-microcode package in Ubuntu
14.04 as that release was already outside of the LTS timeframe when this
hardware platform was launched.

Status

Severity score breakdown

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-20569
• https://www.amd.com/en/resources/product-security/bulletin/amd-sb-7005.html
• https://lore.kernel.org/linux-firmware/20230718231959.3163407-1-john.allen@amd.com/T/#meaa8272d3d5799ffebc729eeaaabb3a14d32665f
• https://ubuntu.com/security/notices/USN-6319-1
• NVD
• Launchpad
• Debian