vulnerability

Ubuntu: (CVE-2021-3735): qemu vulnerability

Try Surface Command

Back to search

Severity

CVSS

(AV:L/AC:L/Au:M/C:N/I:N/A:C)

Published

Aug 26, 2022

Added

Jun 26, 2025

Modified

Mar 27, 2026

Description

A deadlock issue was found in the AHCI controller device of QEMU. It occurs on a software reset (ahci_reset_port) while handling a host-to-device Register FIS (Frame Information Structure) packet from the guest. A privileged user inside the guest could use this flaw to hang the QEMU process on the host, resulting in a denial of service condition. The highest threat from this vulnerability is to system availability.

Solution

no-fix-ubuntu-package

References

CVE-2021-3735
https://attackerkb.com/topics/CVE-2021-3735
CWE-400
CWE-667
EUVD-EUVD-2021-27011
https://euvd.enisa.europa.eu/vulnerability/EUVD-2021-27011
https://www.cve.org/CVERecord?id=CVE-2021-3735

Rapid7 Labs

2026 Global Threat Landscape Report

The predictive window has collapsed. Exploitation follows disclosure in days. See how attackers are accelerating and how to stay ahead.

Get report