CVE-2020-15563

Published: 07 July 2020

An issue was discovered in Xen through 4.13.x, allowing x86 HVM guest OS users to cause a hypervisor crash. An inverted conditional in x86 HVM guests' dirty video RAM tracking code allows such guests to make Xen de-reference a pointer guaranteed to point at unmapped space. A malicious or buggy HVM guest may cause the hypervisor to crash, resulting in Denial of Service (DoS) affecting the entire host. Xen versions from 4.8 onwards are affected. Xen versions 4.7 and earlier are not affected. Only x86 systems are affected. Arm systems are not affected. Only x86 HVM guests using shadow paging can leverage the vulnerability. In addition, there needs to be an entity actively monitoring a guest's video frame buffer (typically for display purposes) in order for such a guest to be able to leverage the vulnerability. x86 PV guests, as well as x86 HVM guests using hardware assisted paging (HAP), cannot leverage the vulnerability.

Priority

Medium

CVSS 3 base score: 6.5

Status

Package Release Status
xen
Launchpad, Ubuntu, Debian
Upstream Needs triage

Ubuntu 20.10 (Groovy Gorilla) Not vulnerable
(4.11.4+24-gddaaccbbab-1ubuntu2)
Ubuntu 20.04 LTS (Focal Fossa) Needs triage

Ubuntu 18.04 LTS (Bionic Beaver) Needs triage

Ubuntu 16.04 LTS (Xenial Xerus) Needs triage

Ubuntu 14.04 ESM (Trusty Tahr) Does not exist

Binaries built from this source package are in Universe and so are supported by the community.

Notes

AuthorNote
mdeslaur
hypervisor packages are in universe. For
issues in the hypervisor, add appropriate
tags to each section, ex:
Tags_xen: universe-binary

References