// For flags

CVE-2021-22543

Improper memory handling in Linux KVM

Severity Score

8.7
*CVSS v4

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

An issue was discovered in Linux: KVM through Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks and can lead to pages being freed while still accessible by the VMM and guest. This allows users with the ability to start and control a VM to read/write random pages of memory and can result in local privilege escalation.

Se detectó un problema en Linux: KVM mediante del manejo inapropiado de Los vmas VM_IO|VM_PFNMAP en KVM pueden omitir unas comprobaciones RO y puede conllevar a que las páginas sean liberadas mientras el VMM y el invitado aún pueden acceder a ellas. Esto permite a usuarios con la capacidad de iniciar y controlar una máquina virtual leer y escribir páginas aleatorias de memoria y puede resultar en una escalada de privilegios local

A flaw was found in the Linux kernel’s KVM implementation, where improper handing of the VM_IO|VM_PFNMAP VMAs in KVM bypasses RO checks and leads to pages being freed while still accessible by the VMM and guest. This flaw allows users who can start and control a VM to read/write random pages of memory, resulting in local privilege escalation. The highest threat from this vulnerability is to confidentiality, integrity, and system availability.

*Credits: David Stevens, Kevin Hamacher, Jann Horn
CVSS Scores
Attack Vector
Local
Attack Complexity
High
Attack Requirements
None
Privileges Required
Low
User Interaction
None
System
Vulnerable | Subsequent
Confidentiality
High
High
Integrity
High
High
Availability
Low
Low
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
High
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
  • 2021-01-05 CVE Reserved
  • 2021-05-26 CVE Published
  • 2023-03-08 EPSS Updated
  • 2024-09-16 CVE Updated
  • 2024-09-16 First Exploit
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-119: Improper Restriction of Operations within the Bounds of a Memory Buffer
  • CWE-863: Incorrect Authorization
CAPEC
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
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H410c
Search vendor "Netapp" for product "H410c"
--
Safe
Netapp
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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"
2021-05-18
Search vendor "Linux" for product "Linux Kernel" and version "2021-05-18"
-
Affected
Fedoraproject
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Fedora
Search vendor "Fedoraproject" for product "Fedora"
33
Search vendor "Fedoraproject" for product "Fedora" and version "33"
-
Affected
Fedoraproject
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Fedora
Search vendor "Fedoraproject" for product "Fedora"
34
Search vendor "Fedoraproject" for product "Fedora" and version "34"
-
Affected
Debian
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Debian Linux
Search vendor "Debian" for product "Debian Linux"
9.0
Search vendor "Debian" for product "Debian Linux" and version "9.0"
-
Affected
Netapp
Search vendor "Netapp"
Cloud Backup
Search vendor "Netapp" for product "Cloud Backup"
--
Affected
Netapp
Search vendor "Netapp"
Solidfire Baseboard Management Controller Firmware
Search vendor "Netapp" for product "Solidfire Baseboard Management Controller Firmware"
--
Affected