Use After Free Affecting qemu package, versions <1:6.1+dfsg-6


Severity

Recommended
0.0
high
0
10

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Threat Intelligence

EPSS
0.52% (41st percentile)

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  • Snyk IDSNYK-ECHOLATEST-QEMU-18321843
  • published27 Jul 2026
  • disclosed23 Mar 2022

Introduced: 23 Mar 2022

CVE-2021-3748  (opens in a new tab)
CWE-416  (opens in a new tab)

How to fix?

Upgrade Echo:latest qemu to version 1:6.1+dfsg-6 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 Echo. See How to fix? for Echo:latest relevant fixed versions and status.

A use-after-free vulnerability was found in the virtio-net device of QEMU. It could occur when the descriptor's address belongs to the non direct access region, due to num_buffers being set after the virtqueue elem has been unmapped. A malicious guest could use this flaw to crash QEMU, resulting in a denial of service condition, or potentially execute code on the host with the privileges of the QEMU process.

CVSS Base Scores

version 3.1