// For flags

CVE-2020-25601

 

Severity Score

5.5
*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 4.14.x. There is a lack of preemption in evtchn_reset() / evtchn_destroy(). In particular, the FIFO event channel model allows guests to have a large number of event channels active at a time. Closing all of these (when resetting all event channels or when cleaning up after the guest) may take extended periods of time. So far, there was no arrangement for preemption at suitable intervals, allowing a CPU to spend an almost unbounded amount of time in the processing of these operations. Malicious or buggy guest kernels can mount a Denial of Service (DoS) attack affecting the entire system. All Xen versions are vulnerable in principle. Whether versions 4.3 and older are vulnerable depends on underlying hardware characteristics.

Se detectó un problema en Xen versiones hasta 4.14.x. Se presenta una carencia de preferencia en evtchn_reset() / evtchn_destroy(). En particular, el modelo de canal de eventos FIFO permite a los invitados tener una gran cantidad de canales de eventos activos simultáneos. Cerrar todos estos (al restablecer todos los canales de eventos o al limpiar después del invitado) puede llevar períodos de tiempo prolongados. Hasta ahora, no había ningún arreglo para la preferencia a intervalos adecuados, lo que permitía que una CPU pasara una cantidad de tiempo casi ilimitada en el procesamiento de estas operaciones. Los kernels invitados maliciosos o con errores pueden montar un ataque de denegación de servicio (DoS) afectando a todo el sistema. Todas las versiones de Xen son vulnerables en principio. Tanto las versiones 4.3 y como las anteriores son vulnerables dependiendo de las características subyacentes del hardware.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
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
  • 2020-09-16 CVE Reserved
  • 2020-09-23 CVE Published
  • 2023-03-08 EPSS Updated
  • 2024-08-04 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
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"
 <= 4.14.0
Search vendor "Xen" for product "Xen" and version " <= 4.14.0"
-
Affected
Debian
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 Debian Linux
Search vendor "Debian" for product "Debian Linux"
 10.0
Search vendor "Debian" for product "Debian Linux" and version "10.0"
-
Affected
Fedoraproject
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 Fedora
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 31
Search vendor "Fedoraproject" for product "Fedora" and version "31"
-
Affected
Fedoraproject
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 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 32
Search vendor "Fedoraproject" for product "Fedora" and version "32"
-
Affected
Fedoraproject
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 Fedora
Search vendor "Fedoraproject" for product "Fedora"
 33
Search vendor "Fedoraproject" for product "Fedora" and version "33"
-
Affected
Opensuse
Search vendor "Opensuse"
 Leap
Search vendor "Opensuse" for product "Leap"
 15.2
Search vendor "Opensuse" for product "Leap" and version "15.2"
-
Affected