What is CVE-2023-20588?

CVE-2023-20588 is a security vulnerability affecting some AMD processors, specifically those using the Zen1 microarchitecture. This issue, caused by a division-by-zero error, can potentially lead to a loss of confidentiality as it allows speculative data to be returned. Systems running on affected AMD processors, including various versions of Debian Linux, Fedora, Microsoft Windows, and Xen, are at risk. While the severity of this vulnerability has not yet been assessed by the National Vulnerability Database, it is crucial for users to be aware of the potential risks and take necessary precautions.

Who is impacted by this?

Impacted systems include Debian Linux versions 10.0, 11.0, and 12.0, various AMD EPYC and Ryzen firmware, Xen, Fedora Project Fedora versions 37, 38, and 39, and Microsoft Windows 10, Windows 11, and Windows Server. This security issue can potentially lead to a loss of confidentiality, as it allows speculative data to be returned, putting users at risk.

What should I do if I’m affected?

If you're affected by the CVE-2023-20588 vulnerability, it's important to take action to protect your system. Follow these steps:

1. Apply the patches for Xen or the Linux kernel, as appropriate for your system. See the Xen Security Advisory and the Linux kernel commit for details.

2. Assess your workload and decide whether to enable or disable Simultaneous Multi-Threading (SMT) on your system, as the patches are only effective when combined with disabling SMT. Consult your system administrator for guidance.

Is this in CISA’s Known Exploited Vulnerabilities Catalog?

The CVE-2023-20588 vulnerability, known as a division-by-zero error on some AMD processors, is not listed in CISA's Known Exploited Vulnerabilities Catalog.

Weakness Enumeration

The weakness enumeration for this vulnerability is categorized as CWE-369, which is a divide by zero issue affecting some AMD processors with Zen1 microarchitecture.

Learn More

CVE-2023-20588 is a security vulnerability affecting AMD processors with Zen1 microarchitecture, potentially leading to a loss of confidentiality. For a comprehensive understanding of this issue, including its description, severity, technical details, and affected software configurations, refer to the NVD Page page or the sources listed below.

• Xen Security Advisory 439 v1 (CVE-2023-20588) - x86 AMD: Divide speculative information leak

• oss-security - Xen Security Advisory 439 v2 (CVE-2023-20588) - x86 AMD: Divide speculative information leak

• oss-security - Re: Xen Security Advisory 439 v1 (CVE-2023-20588) - x86 AMD: Divide speculative information leak