VULNERABILITY INTELLIGENCE

CVE-2021-3527

CVSS score5.5 MEDIUM
EPSS probability0.37%
CISA KEVNot currently listed
Published2021-05-26
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Description

A flaw was found in the USB redirector device (usb-redir) of QEMU. Small USB packets are combined into a single, large transfer request, to reduce the overhead and improve performance. The combined size of the bulk transfer is used to dynamically allocate a variable length array (VLA) on the stack without proper validation. Since the total size is not bounded, a malicious guest could use this flaw to influence the array length and cause the QEMU process to perform an excessive allocation on the stack, resulting in a denial of service.

Weakness classification

  • CWE-770: Allocation of Resources Without Limits or Throttling

Primary references