CVE-2021-28701

Published Sep 8, 2021

Last updated a year ago

Overview

Description
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.
Source
security@xen.org
NVD status
Modified

Risk scores

CVSS 3.1

Type
Primary
Base score
7.8
Impact score
6
Exploitability score
1.1
Vector string
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Severity
HIGH

CVSS 2.0

Type
Primary
Base score
4.4
Impact score
6.4
Exploitability score
3.4
Vector string
AV:L/AC:M/Au:N/C:P/I:P/A:P

Weaknesses

nvd@nist.gov
CWE-362

Social media

Hype score
Not currently trending

Configurations