x86/AMD: Debug Mask handling
CVE-2023-34328

5.5MEDIUM

Key Information:

Vendor

Xen Project
Status
Xen
Vendor
CVE Published:
5 January 2024

What is CVE-2023-34328?

The vulnerability associated with Xen's handling of AMD CPUs introduces significant concerns for virtualization environments. Specifically, there are errors in how the Xen project manages the guest state for PV (Paravirtualized) vCPUs, leading to potential exploitation scenarios. A PV vCPU can manipulate the global descriptor table (GDT) by placing a breakpoint over it, which may allow it to exploit prior vulnerabilities, such as XSA-156 and CVE-2015-8104. This action can potentially result in complete CPU lock-ups, showcasing the critical need for patches and protective measures within systems utilizing Xen virtualization on AMD hardware.

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.
.