// For flags

CVE-2021-4207

QEMU: QXL: double fetch in qxl_cursor() can lead to heap buffer overflow

Severity Score

8.2
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

A flaw was found in the QXL display device emulation in QEMU. A double fetch of guest controlled values `cursor->header.width` and `cursor->header.height` can lead to the allocation of a small cursor object followed by a subsequent heap-based buffer overflow. A malicious privileged guest user could use this flaw to crash the QEMU process on the host or potentially execute arbitrary code within the context of the QEMU process.

Se ha encontrado un fallo en la emulación del dispositivo de visualización QXL en QEMU. Una doble obtención de los valores controlados por el huésped "cursor-)header.width" y "cursor-)header.height" puede conllevar a una asignación de un pequeño objeto cursor seguido de un posterior desbordamiento del búfer en la región heap de la memoria. Un usuario invitado con privilegios maliciosos podría usar este fallo para bloquear el proceso de QEMU en el host o ejecutar potencialmente código arbitrario dentro del contexto del proceso de QEMU

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
High
Privileges Required
High
User Interaction
None
Scope
Changed
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
  • 2022-01-13 CVE Reserved
  • 2022-04-29 CVE Published
  • 2024-07-21 EPSS Updated
  • 2024-08-03 CVE Updated
  • 2024-08-03 First Exploit
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')
  • CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Qemu
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Qemu
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< 7.0.0
Search vendor "Qemu" for product "Qemu" and version " < 7.0.0"
-
Affected
Redhat
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Enterprise Linux
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8.0
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-
Affected
Redhat
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Enterprise Linux
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8.0
Search vendor "Redhat" for product "Enterprise Linux" and version "8.0"
advanced_virtualization
Affected
Debian
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Debian Linux
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10.0
Search vendor "Debian" for product "Debian Linux" and version "10.0"
-
Affected
Debian
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Debian Linux
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11.0
Search vendor "Debian" for product "Debian Linux" and version "11.0"
-
Affected