CVE-2021-3409

Name: CVE-2021-3409
Creator: NVD / NIST
Published: 2021-03-23T21:15:14.697+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

MEDIUMCVSS 5.7/10EPSS 0.48%

Last modified Jun 17, 2026

CVE-2021-3409 is a medium-severity vulnerability rated 5.7/10 on the CVSS scale. The patch for CVE-2020-17380/CVE-2020-25085 was found to be ineffective, thus making QEMU vulnerable to the out-of-bounds read/write access issues previously found in the SDHCI controller emulation code. This flaw allows a malicious privileged guest to crash the QEMU process on the host, resulting in a denial of service or potential code execution. EPSS estimates a 0.48% chance of exploitation in the next 30 days.

Description

The patch for CVE-2020-17380/CVE-2020-25085 was found to be ineffective, thus making QEMU vulnerable to the out-of-bounds read/write access issues previously found in the SDHCI controller emulation code. This flaw allows a malicious privileged guest to crash the QEMU process on the host, resulting in a denial of service or potential code execution. QEMU up to (including) 5.2.0 is affected by this.

Metrics

CVSS 3.1

5.7/10

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

EPSS Probability

0.48%

38.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Qemu	Qemu	<= 5.2.0
Redhat	Enterprise Linux	7.0
Fedoraproject	Fedora	33
Debian	Debian Linux	9.0

References

https://bugzilla.redhat.com/show_bug.cgi?id=1928146Issue Tracking, Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/04/msg00009.htmlThird Party Advisory
https://security.gentoo.org/glsa/202208-27Third Party Advisory
https://security.netapp.com/advisory/ntap-20210507-0001/Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/03/09/1Mailing List, Patch, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=1928146Issue Tracking, Patch, Third Party Advisory
https://lists.debian.org/debian-lts-announce/2021/04/msg00009.htmlThird Party Advisory
https://security.gentoo.org/glsa/202208-27Third Party Advisory
https://security.netapp.com/advisory/ntap-20210507-0001/Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/03/09/1Mailing List, Patch, Third Party Advisory

Timeline

Published: Mar 23, 2021
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3409?

How severe is CVE-2021-3409?

CVE-2021-3409 has a CVSS score of 5.7/10 (MEDIUM severity). The EPSS model estimates a 0.48% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3409?

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-2021-3409?

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

Scan your code now

Source: NVD / NIST