CVE-2021-3847

Name: CVE-2021-3847
Creator: NVD / NIST
Published: 2022-04-01T23:15:10.597+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.45%

Last modified Jun 17, 2026

CVE-2021-3847 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. An unauthorized access to the execution of the setuid file with capabilities flaw in the Linux kernel OverlayFS subsystem was found in the way user copying a capable file from a nosuid mount into another mount. A local user could use this flaw to escalate their privileges on the system.. EPSS estimates a 0.45% chance of exploitation in the next 30 days.

Description

An unauthorized access to the execution of the setuid file with capabilities flaw in the Linux kernel OverlayFS subsystem was found in the way user copying a capable file from a nosuid mount into another mount. A local user could use this flaw to escalate their privileges on the system.

Metrics

CVSS 3.1

7.8/10

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

EPSS Probability

0.45%

36.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	<= 5.17.0
Fedoraproject	Fedora	34

References

https://bugzilla.redhat.com/show_bug.cgi?id=2009704Issue Tracking, Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/10/14/3Mailing List, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2009704Issue Tracking, Third Party Advisory
https://www.openwall.com/lists/oss-security/2021/10/14/3Mailing List, Third Party Advisory

Timeline

Published: Apr 1, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-3847?

How severe is CVE-2021-3847?

CVE-2021-3847 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.45% probability of exploitation in the next 30 days.

How do I fix CVE-2021-3847?

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-2021-3847?

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

Scan your code now

Source: NVD / NIST