CVE-2020-29570

Debian Security Advisory 4812-1

Severity Score

6.2

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

An issue was discovered in Xen through 4.14.x. Recording of the per-vCPU control block mapping maintained by Xen and that of pointers into the control block is reversed. The consumer assumes, seeing the former initialized, that the latter are also ready for use. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system.

Se detectó un problema en Xen versiones hasta 4.14.x. Se invierte la grabación de la asignación de bloques de control por vCPU mantenida por Xen y la de los punteros en el bloque de control. El consumidor asume, al visualizar el primero inicializado, que los segundos también están listos para su uso. Los kernels invitados maliciosos o con errores pueden montar un ataque de Denegación de Servicio (DoS) que afecte a todo el sistema

An update that solves 7 vulnerabilities and has two fixes is now available. This update for xen fixes the following issues. Fixed an issue which could have allowed leak of non-sensitive data to administrator guests. Fixed an issue which could have allowd to new domains to inherit existing node permissions. Fixed an issue where guests could disturb domain cleanup. Fixed an issue where guests could crash xenstored via watchs. Fixed an undue recursion in x86 HVM context switch code. Fixed an issue where FIFO event channels control block related ordering. Fixed an issue where FIFO event channels control structure ordering. This update was imported from the SUSE:SLE-15-SP2:Update update project.

*Credits: N/A

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Attack Vector

Local

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

2020-12-04 CVE Reserved
2020-12-15 CVE Published
2024-08-04 CVE Updated
2025-03-30 EPSS Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-770: Allocation of Resources Without Limits or Throttling

CAPEC

References (6)

URL	Tag	Source
http://www.openwall.com/lists/oss-security/2020/12/16/4	Mailing List

URL	Date	SRC

URL	Date	SRC
https://xenbits.xenproject.org/xsa/advisory-358.html	2023-11-07

URL	Date	SRC
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/2C6M6S3CIMEBACH6O7V4H2VDANMO6TVA	2023-11-07
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/OBLV6L6Q24PPQ2CRFXDX4Q76KU776GKI	2023-11-07
https://security.gentoo.org/glsa/202107-30	2023-11-07
https://www.debian.org/security/2020/dsa-4812	2023-11-07

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"				>= 4.4.0 <= 4.14.0 Search vendor "Xen" for product "Xen" and version " >= 4.4.0 <= 4.14.0"		-		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
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				32 Search vendor "Fedoraproject" for product "Fedora" and version "32"		-		Affected
Fedoraproject Search vendor "Fedoraproject"		Fedora Search vendor "Fedoraproject" for product "Fedora"				33 Search vendor "Fedoraproject" for product "Fedora" and version "33"		-		Affected