Vulnerability Monitor

The vendors, products, and vulnerabilities you care about

CVE-2021-20221


An out-of-bounds heap buffer access issue was found in the ARM Generic Interrupt Controller emulator of QEMU up to and including qemu 4.2.0on aarch64 platform. The issue occurs because while writing an interrupt ID to the controller memory area, it is not masked to be 4 bits wide. It may lead to the said issue while updating controller state fields and their subsequent processing. A privileged guest user may use this flaw to crash the QEMU process on the host resulting in DoS scenario.


Security Impact Summary

This vulnerability carries a MEDIUM severity rating with a CVSS v3.1 score of 6.0, requiring local system access to exploit with relatively low complexity without requiring user interaction . The vulnerability impacts and availability (service disruption) for affected systems. Impacting 3 products from qemu, from redhat, from debian organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2021-05-13T16:15:07.697

Last Modified

2024-11-21T05:46:09.497

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 6.0 (MEDIUM)

CVSSv2 Vector

AV:L/AC:L/Au:N/C:N/I:N/A:P

  • Access Vector: LOCAL
  • Access Complexity: LOW
  • Authentication: NONE
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: PARTIAL
Exploitability Score

3.9

Impact Score

2.9

Weaknesses
  • Type: Secondary
    CWE-125
  • Type: Secondary
    CWE-787

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application qemu qemu ≤ 4.2.0 Yes
Operating System redhat enterprise_linux 8.0 Yes
Operating System redhat enterprise_linux 8.0 Yes
Operating System debian debian_linux 9.0 Yes
Operating System debian debian_linux 10.0 Yes

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For qemu's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.