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Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVE-2021-4207

High
8.2/10

Summary

A flaw was found in the QXL display device emulation in QEMU before v7.0.0-rc4. 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.

  • LOW
  • LOCAL
  • HIGH
  • CHANGED
  • NONE
  • HIGH
  • HIGH
  • HIGH

CWE-362 - Race Condition

A race condition occurs in a shared memory program when two threads/processes access the same shared memory data, and at least one thread executes a write operation. This vulnerability manipulates the time to check vs. time to use (TOC/TOU) gap between the threads in the critical section to cause disorientation in the shared data. The impact can vary from compromising the confidentiality of the system to causing the system to crash or to execute arbitrary code.

References

Advisory Timeline

  • Published