4.4
CVSSv2

CVE-2021-28701

Published: 08/09/2021 Updated: 07/11/2023
CVSS v2 Base Score: 4.4 | Impact Score: 6.4 | Exploitability Score: 3.4
CVSS v3 Base Score: 7.8 | Impact Score: 6 | Exploitability Score: 1.1
VMScore: 393
Vector: AV:L/AC:M/Au:N/C:P/I:P/A:P

Vulnerability Summary

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.

Vulnerability Trend

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xen xen

debian debian linux 11.0

fedoraproject fedora 33

fedoraproject fedora 34

fedoraproject fedora 35

Vendor Advisories

Multiple vulnerabilities have been discovered in the Xen hypervisor, which could result in privilege escalation, denial of service or information leaks With the end of upstream support for the 411 branch, the version of xen in the oldstable distribution (buster) is no longer supported If you rely on security support for your Xen installation an ...
Description of Problem Several security issues have been discovered in Citrix Hypervisor that, collectively, may allow privileged code in a guest VM to compromise or crash the hostThese issues have the following identifiers:  CVE-IDDescriptionPre-requisitesCVE-2021-28694Host denial of serviceMalicious privileged code execution in a guest VM r ...

Mailing Lists

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Xen Security Advisory CVE-2021-28701 / XSA-384 version 3 Another race in XENMAPSPACE_grant_table handling UPDATES IN VERSION 3 ==================== Public release ISSUE DESCRIPTION ================= Guests are permitted access to certain Xe ...