// For flags

CVE-2021-20203

Ubuntu Security Notice USN-5307-1

Severity Score

3.2
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

1
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

An integer overflow issue was found in the vmxnet3 NIC emulator of the QEMU for versions up to v5.2.0. It may occur if a guest was to supply invalid values for rx/tx queue size or other NIC parameters. A privileged guest user may use this flaw to crash the QEMU process on the host resulting in DoS scenario.

Se encontró un problema de desbordamiento de enteros en el emulador de NIC vmxnet3 de QEMU para versiones hasta v5.2.0. Puede ocurrir si un invitado estaba suministrando valores no válidos para el tamaño de la cola rx/tx u otros parámetros de NIC. Un usuario invitado privilegiado puede usar este fallo para bloquear el proceso QEMU en el host, resultando en un escenario de DoS

Gaoning Pan discovered that QEMU incorrectly handled the floppy disk emulator. An attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service. Gaoning Pan discovered that the QEMU vmxnet3 NIC emulator incorrectly handled certain values. An attacker inside the guest could use this issue to cause QEMU to crash, resulting in a denial of service. It was discovered that the QEMU vhost-user GPU device contained several security issues. An attacker inside the guest could use these issues to cause QEMU to crash, resulting in a denial of service, leak sensitive information, or possibly execute arbitrary code. This issue only affected Ubuntu 21.10.

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
High
User Interaction
None
Scope
Changed
Confidentiality
None
Integrity
None
Availability
Low
Attack Vector
Local
Attack Complexity
Low
Authentication
None
Confidentiality
None
Integrity
None
Availability
Partial
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2020-12-17 CVE Reserved
  • 2021-02-25 CVE Published
  • 2024-08-03 CVE Updated
  • 2024-08-03 First Exploit
  • 2025-03-30 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
CWE
  • CWE-190: Integer Overflow or Wraparound
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"
<= 5.2.0
Search vendor "Qemu" for product "Qemu" and version " <= 5.2.0"
-
Affected
Fedoraproject
Search vendor "Fedoraproject"
Fedora
Search vendor "Fedoraproject" for product "Fedora"
33
Search vendor "Fedoraproject" for product "Fedora" and version "33"
-
Affected
Debian
Search vendor "Debian"
Debian Linux
Search vendor "Debian" for product "Debian Linux"
9.0
Search vendor "Debian" for product "Debian Linux" and version "9.0"
-
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