Allocation of Resources Without Limits or Throttling Affecting qemu package, versions <1:6.0+dfsg-2expubuntu1


Severity

Recommended
low

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.37% (31st percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-UBUNTU2510-QEMU-15735582
  • published21 Mar 2026
  • disclosed26 May 2021

Introduced: 26 May 2021

CVE-2021-3527  (opens in a new tab)
CWE-770  (opens in a new tab)

How to fix?

Upgrade Ubuntu:25.10 qemu to version 1:6.0+dfsg-2expubuntu1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream qemu package and not the qemu package as distributed by Ubuntu. See How to fix? for Ubuntu:25.10 relevant fixed versions and status.

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.

CVSS Base Scores

version 3.1