x86/AMD: Debug Mask handling
CVE-2023-34327

5.5MEDIUM

Key Information:

Vendor

Xen Project
Status
Xen
Vendor
CVE Published:
5 January 2024

What is CVE-2023-34327?

AMD CPUs, starting from approximately 2014, have enhancements designed for x86 debugging capabilities, which are supported by the Xen hypervisor. However, vulnerabilities exist in the way Xen processes the state of guest virtual machines. In particular, an HVM virtual CPU may inadvertently continue to operate under the debug mask state of a preceding vCPU, which could lead to significant operational issues, including denial of service. The interaction of these CPU features and Xen's current handling mechanisms must be carefully managed to safeguard against potential disruptions in service.

Affected Version(s)

Xen consult Xen advisory XSA-444

References

https://xenbits.xenproject.org/xsa/advisory-444.html

CVSS V3.1

Score:
5.5
Severity:
MEDIUM
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Local
Attack Complexity:
Low
Privileges Required:
Low
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

Credit

This issue was discovered by Andrew Cooper of XenServer.
.