// For flags

CVE-2020-15566

 

Severity Score

6.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

An issue was discovered in Xen through 4.13.x, allowing guest OS users to cause a host OS crash because of incorrect error handling in event-channel port allocation. The allocation of an event-channel port may fail for multiple reasons: (1) port is already in use, (2) the memory allocation failed, or (3) the port we try to allocate is higher than what is supported by the ABI (e.g., 2L or FIFO) used by the guest or the limit set by an administrator (max_event_channels in xl cfg). Due to the missing error checks, only (1) will be considered an error. All the other cases will provide a valid port and will result in a crash when trying to access the event channel. When the administrator configured a guest to allow more than 1023 event channels, that guest may be able to crash the host. When Xen is out-of-memory, allocation of new event channels will result in crashing the host rather than reporting an error. Xen versions 4.10 and later are affected. All architectures are affected. The default configuration, when guests are created with xl/libxl, is not vulnerable, because of the default event-channel limit.

Se detectó un problema en Xen versiones hasta 413.x, que permite a usuarios invitados del Sistema Operativo causar un bloqueo del Sistema Operativo host debido a un manejo incorrecto de errores en la asignación de puertos del canal de eventos. La asignación de un puerto de canal de eventos puede fallar por varias razones: (1) el puerto ya está en uso, (2) la asignación de memoria falló o (3) el puerto que intentamos asignar es superior al que admite el ABI (por ejemplo, 2L o FIFO) usado por el invitado o el límite establecido por un administrador (max_event_channels en xl cfg). Debido a la falta de comprobaciones de error, solo (1) se considerará un error. Todos los demás casos proporcionarán un puerto válido y resultarán en un bloqueo al intentar acceder al canal de eventos. Cuando el administrador configuraba un invitado para permitir más de 1023 canales de eventos, ese invitado puede bloquear el host. Cuando Xen se queda sin memoria, la asignación de nuevos canales de eventos resultará en el bloqueo del host en lugar de informar un error. Xen versiones 4.10 y posteriores están afectadas. Todas las arquitecturas están afectadas. La configuración predeterminada, cuando los invitados son creados con xl/libxl, no es vulnerable, debido al límite predeterminado del canal de eventos

*Credits: N/A
CVSS Scores
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
Medium
Authentication
None
Confidentiality
None
Integrity
None
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2020-07-06 CVE Reserved
  • 2020-07-07 CVE Published
  • 2023-03-08 EPSS Updated
  • 2024-08-04 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-754: Improper Check for Unusual or Exceptional Conditions
CAPEC
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"
>= 4.10.0 <= 4.13.1
Search vendor "Xen" for product "Xen" and version " >= 4.10.0 <= 4.13.1"
-
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