CVE-2021-4037

MediumCVSS 4.4

Published: 24/08/2022(UTC)Updated: 10/08/2026(UTC)Translated: 10/08/2026(UTC)NVD NIST

Exploitation Probability (EPSS)

Low risk

0.28%

20th percentile - higher than 20% of all known CVEs

Summary

A vulnerability in the inode_init_owner() function logic in the Linux kernel (fs/inode.c) allows local users to create files on XFS filesystems with unintended group ownership and with group execution and SGID permission bits set, in a scenario where a directory is SGID and belongs to a group not containing the user. This can lead to excessive permissions.

Risk Assessment

A local user can gain excessive file permissions, potentially leading to privilege escalation and data integrity compromise.

Recommendation

Apply Linux kernel patches that fix this issue. Restrict local access to systems with XFS filesystems.

Original NVD description (English source)

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.