Vulnerability · Published Jan 5, 2024 · Assigned by XEN
CVE-2023-34327x86/AMD: Debug Mask handling
Medium 5.5
In plain English
A medium-severity security flaw in Xen from Xen. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 16% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | xen | 4.17.2-r3 | ALPINE-CVE-2023-34327 |
| Alpine:v3.21 | xen | 4.17.2-r3 | ALPINE-CVE-2023-34327 |
| Alpine:v3.22 | xen | 4.17.2-r3 | ALPINE-CVE-2023-34327 |
| Alpine:v3.23 | xen | 4.17.2-r3 | ALPINE-CVE-2023-34327 |
| Alpine:v3.24 | xen | 4.17.2-r3 | ALPINE-CVE-2023-34327 |
| Debian:12 | xen | 4.17.2+76-ge1f9cb16e2-1~deb12u1 | DEBIAN-CVE-2023-34327 |
| Debian:13 | xen | 4.17.2+55-g0b56bed864-1 | DEBIAN-CVE-2023-34327 |
| Debian:14 | xen | 4.17.2+55-g0b56bed864-1 | DEBIAN-CVE-2023-34327 |
| Ubuntu:22.04:LTS | xen | no fix listed | UBUNTU-CVE-2023-34327 |
| Ubuntu:24.04:LTS | xen | no fix listed | UBUNTU-CVE-2023-34327 |
| Ubuntu:25.10 | xen | no fix listed | UBUNTU-CVE-2023-34327 |
| Ubuntu:26.04:LTS | xen | no fix listed | UBUNTU-CVE-2023-34327 |
| Ubuntu:26.10 | xen | no fix listed | UBUNTU-CVE-2023-34327 |