CVE-2021-28711

Severity Score

6.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Rogue backends can cause DoS of guests via high frequency events T[his CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Xen offers the ability to run PV backends in regular unprivileged guests, typically referred to as "driver domains". Running PV backends in driver domains has one primary security advantage: if a driver domain gets compromised, it doesn't have the privileges to take over the system. However, a malicious driver domain could try to attack other guests via sending events at a high frequency leading to a Denial of Service in the guest due to trying to service interrupts for elongated amounts of time. There are three affected backends: * blkfront patch 1, CVE-2021-28711 * netfront patch 2, CVE-2021-28712 * hvc_xen (console) patch 3, CVE-2021-28713

Los backends fraudulentos pueden causar DoS de los huéspedes por medio de eventos de alta frecuencia T[este registro de información CNA es relacionado con múltiples CVEs; el texto explica qué aspectos/vulnerabilidades corresponden a cada CVE]. Xen ofrece la posibilidad de ejecutar backends PV en huéspedes regulares sin privilegios, típicamente referidos como "driver domains". Ejecutar backends PV en dominios de controladores presenta una ventaja principal de seguridad: si un dominio de controladores está comprometido, no presenta los privilegios para tomar el control del sistema. Sin embargo, un dominio de controladores malicioso podría intentar atacar a otros huéspedes mediante el envío de eventos con una alta frecuencia, conllevando a una denegación de servicio en el huésped debido a que intentaría dar servicio a las interrupciones durante largos periodos de tiempo. Se presentan tres backends afectados: * blkfront parche 1, CVE-2021-28711 * netfront parche 2, CVE-2021-28712 * hvc_xen (consola) parche 3, CVE-2021-28713

*Credits: This issue was discovered by Jürgen Groß of SUSE.

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Changed

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Local

Attack Complexity

Low

Authentication

None

Confidentiality

None

Integrity

None

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-03-18 CVE Reserved
2022-01-05 CVE Published
2023-07-29 EPSS Updated
2024-08-03 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CAPEC

References (5)

URL	Tag	Source
https://lists.debian.org/debian-lts-announce/2022/03/msg00011.html	Mailing List
https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html	Mailing List

URL	Date	SRC

URL	Date	SRC
https://xenbits.xenproject.org/xsa/advisory-391.txt	2022-04-06

URL	Date	SRC
https://www.debian.org/security/2022/dsa-5050	2022-04-06
https://www.debian.org/security/2022/dsa-5096	2022-04-06

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"				-		-		Affected
Debian Search vendor "Debian"		Debian Linux Search vendor "Debian" for product "Debian Linux"				9.0 Search vendor "Debian" for product "Debian Linux" and version "9.0"		-		Affected
Debian Search vendor "Debian"		Debian Linux Search vendor "Debian" for product "Debian Linux"				10.0 Search vendor "Debian" for product "Debian Linux" and version "10.0"		-		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