CVE-2021-28706

Severity Score

8.6

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

guests may exceed their designated memory limit When a guest is permitted to have close to 16TiB of memory, it may be able to issue hypercalls to increase its memory allocation beyond the administrator established limit. This is a result of a calculation done with 32-bit precision, which may overflow. It would then only be the overflowed (and hence small) number which gets compared against the established upper bound.

Los huéspedes pueden exceder su límite de memoria designado Cuando a un huésped se le permite tener cerca de 16TiB de memoria, puede ser capaz de emitir hypercalls para aumentar su asignación de memoria más allá del límite establecido por el administrador. Esto es el resultado de un cálculo realizado con precisión de 32 bits, que puede desbordarse. En ese caso, sólo el número desbordado (y por tanto pequeño) se comparará con el límite superior establecido

*Credits: This issue was discovered by Julien Grall of Amazon.

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Network

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Complete

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-03-18 CVE Reserved
2021-11-24 CVE Published
2024-08-03 CVE Updated
2024-10-02 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-770: Allocation of Resources Without Limits or Throttling

CAPEC

References (5)

URL	Tag	Source

URL	Date	SRC

URL	Date	SRC
https://xenbits.xenproject.org/xsa/advisory-385.txt	2024-02-04

URL	Date	SRC
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/I7ZGWVVRI4XY2XSTBI3XEMWBXPDVX6OT	2024-02-04
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PXUI4VMD52CH3T7YXAG3J2JW7ZNN3SXF	2024-02-04
https://security.gentoo.org/glsa/202402-07	2024-02-04
https://www.debian.org/security/2021/dsa-5017	2024-02-04

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Xen Search vendor "Xen"		Xen Search vendor "Xen" for product "Xen"				>= 3.2 < 4.12 Search vendor "Xen" for product "Xen" and version " >= 3.2 < 4.12"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				34 Search vendor "Fedoraproject" for product "Fedora" and version "34"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				35 Search vendor "Fedoraproject" for product "Fedora" and version "35"		-		Affected
Debian Search vendor "Debian"		Debian Linux Search vendor "Debian" for product "Debian Linux"				11.0 Search vendor "Debian" for product "Debian Linux" and version "11.0"		-		Affected