// For flags

CVE-2021-3750

QEMU: hcd-ehci: DMA reentrancy issue leads to use-after-free

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 DMA reentrancy issue was found in the USB EHCI controller emulation of QEMU. EHCI does not verify if the Buffer Pointer overlaps with its MMIO region when it transfers the USB packets. Crafted content may be written to the controller's registers and trigger undesirable actions (such as reset) while the device is still transferring packets. This can ultimately lead to a use-after-free issue. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition, or potentially execute arbitrary code within the context of the QEMU process on the host. This flaw affects QEMU versions before 7.0.0.

Se ha encontrado un problema de reentrada DMA en la emulación del controlador USB EHCI de QEMU. EHCI no verifica si el puntero del búfer es solapado con su región MMIO cuando transfiere los paquetes USB. El contenido diseñado puede escribirse en los registros del controlador y desencadenar acciones no deseadas (como el reinicio) mientras el dispositivo sigue transfiriendo paquetes. Esto puede conllevar en última instancia a un problema de uso de memoria previamente liberada. Un huésped malicioso podría usar este fallo para bloquear el proceso de QEMU en el host, resultando en una condición de denegación de servicio, o potencialmente ejecutar código arbitrario dentro del contexto del proceso de QEMU en el host. Este fallo afecta a QEMU versiones anteriores a 7.0.0

A DMA reentrancy issue was found in the USB EHCI controller emulation of QEMU. EHCI does not verify if the Buffer Pointer overlaps with its MMIO region when it transfers the USB packets. Crafted content may be written to the controller's registers and trigger undesirable actions (such as reset) while the device is still transferring packets. This can ultimately lead to a use-after-free issue. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition, or potentially execute arbitrary code within the context of the QEMU process on the host.

*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
  • 2021-08-30 CVE Reserved
  • 2022-05-02 CVE Published
  • 2024-07-24 EPSS Updated
  • 2024-08-03 CVE Updated
  • 2024-08-03 First Exploit
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-416: Use After Free
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Qemu
Search vendor "Qemu"
Qemu
Search vendor "Qemu" for product "Qemu"
< 7.0.0
Search vendor "Qemu" for product "Qemu" and version " < 7.0.0"
-
Affected
Redhat
Search vendor "Redhat"
Enterprise Linux
Search vendor "Redhat" for product "Enterprise Linux"
8.0
Search vendor "Redhat" for product "Enterprise Linux" and version "8.0"
-
Affected
Redhat
Search vendor "Redhat"
Enterprise Linux
Search vendor "Redhat" for product "Enterprise Linux"
8.0
Search vendor "Redhat" for product "Enterprise Linux" and version "8.0"
advanced_virtualization
Affected