Home/CVE/A deadlock issue was found in the AHCI controller device of QEMU. It occurs on a software reset (ahci_reset_port) while
CVE

CVE-2021-3735

A deadlock issue was found in the AHCI controller device of QEMU. It occurs on a software reset (ahci_reset_port) while

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.

MEDIUM · CVSS 4.4 EPSS 0.0013
Monitor
  • No active-exploitation, high-EPSS, or public-exploit signals - routine patching cadence
Sigma rules1 YARA rules0
⬡

Weakness Classification

CWE-400Uncontrolled Resource Consumption
CWE-667Improper Locking
CWE-667Improper Locking
▤

Affected Products & Versions

2
qemuall versions
debian linuxall versions
◈

Sigma Hunt Rules

1
Exact rules name this CVE ID. Product rules name an affected product in their title. Related rules cover techniques used by actors who exploited this CVE. Showing the most relevant matches; the complete related set is on the full drill-down.
productmediumPotentially Suspicious Usage Of Qemu
▣

Scoring & Timeline

4.4
MEDIUM · CVSS v3.1 · secalert@redhat.com
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD26 Aug 2022 · 04:15 PM
CVSS VectorCVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
🔗

References & Sources

4
Source URLs (vendor pages, mailing lists, write-ups). Exploit/PoC links are in their own section above to avoid duplication.
https://access.redhat.com/security/cve/CVE-2021-3735Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1997184Issue TrackingThird Party Advisory
https://security-tracker.debian.org/tracker/CVE-2021-3735Third Party Advisory
https://security.netapp.com/advisory/ntap-20250228-0009/
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