Use After Free Affecting qemu package, versions <1:4.2-3ubuntu6.21


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
0.05% (16th percentile)

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  • Snyk IDSNYK-UBUNTU2004-QEMU-1582337
  • published3 Sept 2021
  • disclosed23 Mar 2022

Introduced: 3 Sep 2021

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

How to fix?

Upgrade Ubuntu:20.04 qemu to version 1:4.2-3ubuntu6.21 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:20.04 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 Scores

version 3.1