CVE-2021-4037

Name: CVE-2021-4037
Creator: NVD / NIST
Published: 2022-08-24T16:15:09.257+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

HIGHCVSS 7.8/10EPSS 0.28%

Last modified Jun 17, 2026

CVE-2021-4037 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. A vulnerability was found in the fs/inode.c:inode_init_owner() function logic of the LInux kernel that allows local users to create files for the XFS file-system with an unintended group ownership and with group execution and SGID permission bits set, in a scenario where a directory is SGID and belongs to a certain group and is writable by a user who is not a member of this group. This can lead to excessive permissions granted in case when they should not. EPSS estimates a 0.28% chance of exploitation in the next 30 days.

Description

A vulnerability was found in the fs/inode.c:inode_init_owner() function logic of the LInux kernel that allows local users to create files for the XFS file-system with an unintended group ownership and with group execution and SGID permission bits set, in a scenario where a directory is SGID and belongs to a certain group and is writable by a user who is not a member of this group. This can lead to excessive permissions granted in case when they should not. This vulnerability is similar to the previous CVE-2018-13405 and adds the missed fix for the XFS.

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

0.28%

19.6th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-284

Affected Software

Vendor	Product	Versions
Linux	Linux Kernel	< 5.11
Debian	Debian Linux	10.0
Debian	Debian Linux	11.0

References

https://access.redhat.com/security/cve/CVE-2021-4037Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2004810Issue Tracking, Permissions Required, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2027239Issue Tracking, Third Party Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=01ea173e103eMailing List, Patch, Vendor Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0fa3ecd87848Mailing List, Patch, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2022/11/msg00001.htmlMailing List, Third Party Advisory
https://www.debian.org/security/2022/dsa-5257Third Party Advisory
https://access.redhat.com/security/cve/CVE-2021-4037Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2004810Issue Tracking, Permissions Required, Third Party Advisory
https://bugzilla.redhat.com/show_bug.cgi?id=2027239Issue Tracking, Third Party Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=01ea173e103eMailing List, Patch, Vendor Advisory
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=0fa3ecd87848Mailing List, Patch, Vendor Advisory
https://lists.debian.org/debian-lts-announce/2022/11/msg00001.htmlMailing List, Third Party Advisory
https://www.debian.org/security/2022/dsa-5257Third Party Advisory

Timeline

Published: Aug 24, 2022
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2021-4037?

How severe is CVE-2021-4037?

CVE-2021-4037 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.28% probability of exploitation in the next 30 days.

How do I fix CVE-2021-4037?

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-2021-4037?

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

Scan your code now

Source: NVD / NIST