Vulnerability Description
A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows an unprivileged local attacker to unmount FUSE filesystems that belong to certain other users who have a UID that is a prefix of the UID of the attacker in its string form. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Kernel | Util-Linux | >= 2.34, < 2.37.3 |
| Fedoraproject | Fedora | 35 |
Related Weaknesses (CWE)
References
- http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_witThird Party AdvisoryVDB Entry
- http://seclists.org/fulldisclosure/2022/Dec/4Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2022/11/30/2Mailing ListThird Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2024631https://access.redhat.com/secBroken LinkIssue Tracking
- https://github.com/util-linux/util-linux/commit/57202f5713afa2af20ffbb6ab5331481PatchThird Party Advisory
- https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseRelease NotesVendor Advisory
- https://security.gentoo.org/glsa/202401-08
- https://security.netapp.com/advisory/ntap-20221209-0002/Third Party Advisory
- https://www.openwall.com/lists/oss-security/2022/01/24/2ExploitMailing ListPatch
- http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_witThird Party AdvisoryVDB Entry
- http://seclists.org/fulldisclosure/2022/Dec/4Mailing ListThird Party Advisory
- http://www.openwall.com/lists/oss-security/2022/11/30/2Mailing ListThird Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2024631https://access.redhat.com/secBroken LinkIssue Tracking
- https://github.com/util-linux/util-linux/commit/57202f5713afa2af20ffbb6ab5331481PatchThird Party Advisory
- https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseRelease NotesVendor Advisory
FAQ
What is CVE-2021-3995?
CVE-2021-3995 is a vulnerability with a CVSS score of 5.5 (MEDIUM). A logic error was found in the libmount library of util-linux in the function that allows an unprivileged user to unmount a FUSE filesystem. This flaw allows an unprivileged local attacker to unmount ...
How severe is CVE-2021-3995?
CVE-2021-3995 has been rated MEDIUM with a CVSS base score of 5.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2021-3995?
Check the references section above for vendor advisories and patch information. Affected products include: Kernel Util-Linux, Fedoraproject Fedora.