CVE-2021-3929

Name: CVE-2021-3929
Creator: NVD / NIST
Published: 2022-08-25T20:15:09.417+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 8.2/10EPSS 0.64%

Last modified Jun 17, 2026

CVE-2021-3929 is a high-severity vulnerability rated 8.2/10 on the CVSS scale. A DMA reentrancy issue was found in the NVM Express Controller (NVME) emulation in QEMU. This CVE is similar to CVE-2021-3750 and, just like it, when the reentrancy write triggers the reset function nvme_ctrl_reset(), data structs will be freed leading to a use-after-free issue. EPSS estimates a 0.64% chance of exploitation in the next 30 days.

Description

A DMA reentrancy issue was found in the NVM Express Controller (NVME) emulation in QEMU. This CVE is similar to CVE-2021-3750 and, just like it, when the reentrancy write triggers the reset function nvme_ctrl_reset(), data structs will be freed leading to a use-after-free issue. A malicious guest could use this flaw to crash the QEMU process on the host, resulting in a denial of service condition or, potentially, executing arbitrary code within the context of the QEMU process on the host.

Metrics

CVSS 3.1

8.2/10

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

EPSS Probability

0.64%

46.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Qemu	Qemu	< 7.0.0
Fedoraproject	Fedora	35
Fedoraproject	Fedora	36

References

https://access.redhat.com/security/cve/CVE-2021-3929Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2020298Issue Tracking, Patch, Third Party Advisory
https://gitlab.com/qemu-project/qemu/-/commit/736b01642d85be832385Patch, Third Party Advisory
https://gitlab.com/qemu-project/qemu/-/issues/556Issue Tracking, Third Party Advisory
https://gitlab.com/qemu-project/qemu/-/issues/782Exploit, Issue Tracking, Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XHNN7QJCEQH7AQG5AQP2GEFAQE6K635I/
https://access.redhat.com/security/cve/CVE-2021-3929Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2020298Issue Tracking, Patch, Third Party Advisory
https://gitlab.com/qemu-project/qemu/-/commit/736b01642d85be832385Patch, Third Party Advisory
https://gitlab.com/qemu-project/qemu/-/issues/556Issue Tracking, Third Party Advisory
https://gitlab.com/qemu-project/qemu/-/issues/782Exploit, Issue Tracking, Patch, Third Party Advisory
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/XHNN7QJCEQH7AQG5AQP2GEFAQE6K635I/
https://security.netapp.com/advisory/ntap-20250228-0010/

Timeline

Published: Aug 25, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3929?

How severe is CVE-2021-3929?

CVE-2021-3929 has a CVSS score of 8.2/10 (HIGH severity). The EPSS model estimates a 0.64% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3929?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-3929?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST