Vulnerability · Published May 16, 2024 · Assigned by XEN
CVE-2023-46842x86 HVM hypercalls may trigger Xen bug check
Medium 6.5
In plain English
A medium-severity type confusion 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 8.5% (higher than 95% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Unlike 32-bit PV guests, HVM guests may switch freely between 64-bit and other modes. This in particular means that they may set registers used to pass 32-bit-mode hypercall arguments to values outside of the range 32-bit code would be able to set them to. When processing of hypercalls takes a considerable amount of time, the hypervisor may choose to invoke a hypercall continuation. Doing so involves putting (perhaps updated) hypercall arguments in respective registers. For guests not running in 64-bit mode this further involves a certain amount of translation of the values. Unfortunately internal sanity checking of these translated values assumes high halves of registers to always be clear when invoking a hypercall. When this is found not to be the case, it triggers a consistency check in the hypervisor and causes a crash.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine:v3.20 | xen | 4.18.2-r0 | ALPINE-CVE-2023-46842 |
| Alpine:v3.21 | xen | 4.18.2-r0 | ALPINE-CVE-2023-46842 |
| Alpine:v3.22 | xen | 4.18.2-r0 | ALPINE-CVE-2023-46842 |
| Alpine:v3.23 | xen | 4.18.2-r0 | ALPINE-CVE-2023-46842 |
| Alpine:v3.24 | xen | 4.18.2-r0 | ALPINE-CVE-2023-46842 |
| Debian:12 | xen | 4.17.5+23-ga4e5191dc0-1 | DEBIAN-CVE-2023-46842 |
| Debian:12 | xen | 4.17.5+23-ga4e5191dc0-1 | DSA-5836-1 |
| Debian:13 | xen | 4.19.1-1 | DEBIAN-CVE-2023-46842 |
| Debian:14 | xen | 4.19.1-1 | DEBIAN-CVE-2023-46842 |
| Ubuntu:22.04:LTS | xen | no fix listed | UBUNTU-CVE-2023-46842 |
| Ubuntu:24.04:LTS | xen | no fix listed | UBUNTU-CVE-2023-46842 |
| Ubuntu:25.10 | xen | no fix listed | UBUNTU-CVE-2023-46842 |
| Ubuntu:26.04:LTS | xen | no fix listed | UBUNTU-CVE-2023-46842 |
| Ubuntu:26.10 | xen | no fix listed | UBUNTU-CVE-2023-46842 |
Affected products (as reported)
Weakness: CWE-843 · Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:H
References
- https://xenbits.xenproject.org/xsa/advisory-454.html
- http://xenbits.xen.org/xsa/advisory-454.html
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/D5OK6MH75S7YWD34EWW7QIZTS627RIE3/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/RYAZ7P6YFJ2E3FHKAGIKHWS46KYMMTZH/