CVE-2023-34328 - CVE House
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Status published Unknown CVE-2023-34328

x86/AMD: Debug Mask handling

Vulnerability Description

[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] AMD CPUs since ~2014 have extensions to normal x86 debugging functionality. Xen supports guests using these extensions. Unfortunately there are errors in Xen's handling of the guest state, leading to denials of service. 1) CVE-2023-34327 - An HVM vCPU can end up operating in the context of a previous vCPUs debug mask state. 2) CVE-2023-34328 - A PV vCPU can place a breakpoint over the live GDT. This allows the PV vCPU to exploit XSA-156 / CVE-2015-8104 and lock up the CPU entirely.

Impact Analysis

Refer to official advisory for detailed impact metrics.

Remediation

Ensure systems are updated to the latest vendor-supplied patch levels.

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Credits & Attribution

The following person or organization is credited with identifying this vulnerability, as recorded in the NVD database:

  • This issue was discovered by Andrew Cooper of XenServer.

References

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CVE-2025-58148
x86: Incorrect input sanitisation in Viridian hypercalls
Unknown 0
CVE-2025-58147
x86: Incorrect input sanitisation in Viridian hypercalls
Unknown 0

Affected Vendor

Affected Software

Xen
Vulnerable Versions:
consult Xen advisory XSA-444

Timeline

Official Publish: January 5th, 2024
Last Modified: November 4th, 2025
Added to House: July 22nd, 2026

CVSS Vectors

No vector data available

Weaknesses (CWE)

No CWE data available

MITRE ATT&CK TTPs

No associated TTPs found for this vulnerability.