CVE-2021-3735

Severity: medium (CVSS 4.4 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2022-08-26 · updated 2026-06-17
Weakness: CWE-667

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.

Affected products

Debian Linux: 10.0, 11.0
QEMU: 6.1.0-rc4

References

https://access.redhat.com/security/cve/CVE-2021-3735
https://bugzilla.redhat.com/show_bug.cgi?id=1997184
https://security-tracker.debian.org/tracker/CVE-2021-3735
https://access.redhat.com/security/cve/CVE-2021-3735
https://bugzilla.redhat.com/show_bug.cgi?id=1997184
https://security-tracker.debian.org/tracker/CVE-2021-3735
https://security.netapp.com/advisory/ntap-20250228-0009/

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