Your submission was sent successfully! Close

CVE-2021-28701

Published: 8 September 2021

Another race in XENMAPSPACE_grant_table handling Guests are permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, are de-allocated when a guest switches (back) from v2 to v1. Freeing such pages requires that the hypervisor enforce that no parallel request can result in the addition of a mapping of such a page to a guest. That enforcement was missing, allowing guests to retain access to pages that were freed and perhaps re-used for other purposes. Unfortunately, when XSA-379 was being prepared, this similar issue was not noticed.

Priority

Medium

CVSS 3 base score: 7.8

Status

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

focal Needs triage

hirsute Ignored
(reached end-of-life)
impish Needs triage

jammy Needs triage

trusty Does not exist

upstream Needs triage

xenial Needs triage