CVE-2021-4207: debian debian_linux

Vulnerability summary

CVE-2021-4207 is a high (CVSS 8.2) vulnerability in debian debian_linux. EPSS estimates a 0.40% chance of exploitation in the next 30 days, higher than 34.4% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 29-04-2022
   PublishedVulnerability first disclosed.
2. 21-03-2025
   Last modifiedVulnerability information updated.

Description

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.

• CWE-362Concurrent Execution using Shared Resource with Improper SynchronizationThe product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
• CWE-120Buffer Copy without Checking Size of InputThe product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer.