CVE-2021-28691

Severity Score

7.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

Guest triggered use-after-free in Linux xen-netback A malicious or buggy network PV frontend can force Linux netback to disable the interface and terminate the receive kernel thread associated with queue 0 in response to the frontend sending a malformed packet. Such kernel thread termination will lead to a use-after-free in Linux netback when the backend is destroyed, as the kernel thread associated with queue 0 will have already exited and thus the call to kthread_stop will be performed against a stale pointer.

Un uso de memoria previamente liberada desencadenado por el usuario en Linux xen-netback. Un frontend de red PV malicioso o con errores puede forzar a Linux netback a deshabilitar la interfaz y terminar el hilo del kernel de recepción asociado a la cola 0 en respuesta al envío de un paquete malformado por parte del frontend. Esta terminación del hilo del kernel conllevará un uso de memoria previamente liberada en Linux netback cuando es destruído el backend, ya que el hilo del kernel asociado a la cola 0 ya habrá salido y, por tanto, la llamada a la función kthread_stop se llevará a cabo contra un puntero obsoleto

*Credits: This issue was discovered by Michael Brown of iPXE and diagnosed by Olivier Benjamin, Michael Kurth and Martin Mazein of AWS.

Attack Vector

Local

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Local

Attack Complexity

Low

Authentication

None

Confidentiality

Partial

Integrity

Partial

Availability

Partial

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2021-03-18 CVE Reserved
2021-06-29 CVE Published
2023-03-08 EPSS Updated
2024-08-03 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-416: Use After Free

CAPEC

References (3)

URL	Tag	Source
https://security.netapp.com/advisory/ntap-20210805-0002	Third Party Advisory
https://xenbits.xenproject.org/xsa/advisory-374.txt	Third Party Advisory

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://security.gentoo.org/glsa/202107-30	2022-04-06

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Netapp Search vendor "Netapp"	H410c Firmware Search vendor "Netapp" for product "H410c Firmware"	-	-	Affected	in	Netapp Search vendor "Netapp"	H410c Search vendor "Netapp" for product "H410c"	-	-	Safe
Netapp Search vendor "Netapp"	H300s Firmware Search vendor "Netapp" for product "H300s Firmware"	-	-	Affected	in	Netapp Search vendor "Netapp"	H300s Search vendor "Netapp" for product "H300s"	-	-	Safe
Netapp Search vendor "Netapp"	H500s Firmware Search vendor "Netapp" for product "H500s Firmware"	-	-	Affected	in	Netapp Search vendor "Netapp"	H500s Search vendor "Netapp" for product "H500s"	-	-	Safe
Netapp Search vendor "Netapp"	H700s Firmware Search vendor "Netapp" for product "H700s Firmware"	-	-	Affected	in	Netapp Search vendor "Netapp"	H700s Search vendor "Netapp" for product "H700s"	-	-	Safe
Netapp Search vendor "Netapp"	H300e Firmware Search vendor "Netapp" for product "H300e Firmware"	-	-	Affected	in	Netapp Search vendor "Netapp"	H300e Search vendor "Netapp" for product "H300e"	-	-	Safe
Netapp Search vendor "Netapp"	H500e Firmware Search vendor "Netapp" for product "H500e Firmware"	-	-	Affected	in	Netapp Search vendor "Netapp"	H500e Search vendor "Netapp" for product "H500e"	-	-	Safe
Netapp Search vendor "Netapp"	H700e Firmware Search vendor "Netapp" for product "H700e Firmware"	-	-	Affected	in	Netapp Search vendor "Netapp"	H700e Search vendor "Netapp" for product "H700e"	-	-	Safe
Netapp Search vendor "Netapp"	H410s Firmware Search vendor "Netapp" for product "H410s Firmware"	-	-	Affected	in	Netapp Search vendor "Netapp"	H410s Search vendor "Netapp" for product "H410s"	-	-	Safe
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 5.5.0 < 5.12.2 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.5.0 < 5.12.2"		-		Affected
Netapp Search vendor "Netapp"		Cloud Backup Search vendor "Netapp" for product "Cloud Backup"				-		-		Affected