CVE-2020-29566
Severity CVSS v4.0:
Pending analysis
Type:
Unavailable / Other
Publication date:
15/12/2020
Last modified:
07/11/2023
Description
An issue was discovered in Xen through 4.14.x. When they require assistance from the device model, x86 HVM guests must be temporarily de-scheduled. The device model will signal Xen when it has completed its operation, via an event channel, so that the relevant vCPU is rescheduled. If the device model were to signal Xen without having actually completed the operation, the de-schedule / re-schedule cycle would repeat. If, in addition, Xen is resignalled very quickly, the re-schedule may occur before the de-schedule was fully complete, triggering a shortcut. This potentially repeating process uses ordinary recursive function calls, and thus could result in a stack overflow. A malicious or buggy stubdomain serving a HVM guest can cause Xen to crash, resulting in a Denial of Service (DoS) to the entire host. Only x86 systems are affected. Arm systems are not affected. Only x86 stubdomains serving HVM guests can exploit the vulnerability.
Impact
Base Score 3.x
5.50
Severity 3.x
MEDIUM
Base Score 2.0
4.90
Severity 2.0
MEDIUM
Vulnerable products and versions
| CPE | From | Up to |
|---|---|---|
| cpe:2.3:o:xen:xen:*:*:*:*:*:*:x86:* | 4.14.0 (including) | |
| cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* | ||
| cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:* | ||
| cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:* |
To consult the complete list of CPE names with products and versions, see this page
References to Advisories, Solutions, and Tools
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI/
- https://security.gentoo.org/glsa/202107-30
- https://www.debian.org/security/2020/dsa-4812
- https://xenbits.xenproject.org/xsa/advisory-348.html