// For flags

CVE-2023-34328

x86/AMD: Debug Mask handling

Severity Score

5.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

[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.

[Este registro de información de la CNA se relaciona con múltiples CVE; el texto explica qué aspectos/vulnerabilidades corresponden a cada CVE.] Las CPU AMD desde ~2014 tienen extensiones a la funcionalidad de depuración x86 normal. Xen admite invitados que utilizan estas extensiones. Desafortunadamente, hay errores en el manejo del estado invitado por parte de Xen, lo que lleva a denegaciones de servicio. 1) CVE-2023-34327: una vCPU HVM puede terminar funcionando en el contexto de un estado de máscara de depuración de vCPU anterior. 2) CVE-2023-34328: una vCPU PV puede colocar un punto de interrupción sobre la GDT en vivo. Esto permite que PV vCPU aproveche XSA-156/CVE-2015-8104 y bloquee la CPU por completo.

*Credits: This issue was discovered by Andrew Cooper of XenServer.
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2023-06-01 CVE Reserved
  • 2024-01-05 CVE Published
  • 2024-01-10 EPSS Updated
  • 2024-08-02 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
References (1)
URL Tag Source
URL Date SRC
URL Date SRC
https://xenbits.xenproject.org/xsa/advisory-444.html 2024-01-11
URL Date SRC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Xen
Search vendor "Xen"
 Xen
Search vendor "Xen" for product "Xen"
 >= 4.5.0 < 4.14.0
Search vendor "Xen" for product "Xen" and version " >= 4.5.0 < 4.14.0"
-
Affected