CVE-2021-26933

Published: 17 February 2021

An issue was discovered in Xen 4.9 through 4.14.x. On Arm, a guest is allowed to control whether memory accesses are bypassing the cache. This means that Xen needs to ensure that all writes (such as the ones during scrubbing) have reached the memory before handing over the page to a guest. Unfortunately, the operation to clean the cache is happening before checking if the page was scrubbed. Therefore there is no guarantee when all the writes will reach the memory.

Priority

Medium

CVSS 3 base score: 5.5

Status

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

Ubuntu 21.04 (Hirsute Hippo) Needs triage

Ubuntu 20.10 (Groovy Gorilla) Needs triage

Ubuntu 20.04 LTS (Focal Fossa) Needs triage

Ubuntu 18.04 LTS (Bionic Beaver) Needed

Ubuntu 16.04 ESM (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