CVE-2021-3996
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.
Does this matter?
Lower severity and a low EPSS score (0.63%). Track it; it rarely justifies an emergency change on its own.
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 a local user on a vulnerable system to unmount other users' filesystems that are either world-writable themselves (like /tmp) or mounted in a world-writable directory. An attacker may use this flaw to cause a denial of service to applications that use the affected filesystems.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.63% probability · 48th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-552
- Affected
- kernel/util-linux · fedoraproject/fedora
- Source
- secalert@redhat.com
References
- http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.htmlThird Party Advisory
- http://seclists.org/fulldisclosure/2022/Dec/4Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2022/11/30/2Mailing List, Third Party Advisory
- https://access.redhat.com/security/cve/CVE-2021-3996Issue Tracking, Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2024628Issue Tracking, Patch, Third Party Advisory
- https://github.com/util-linux/util-linux/commit/166e87368ae88bf31112a30e078cceae637f4cdbPatch, Third Party Advisory
- https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotesRelease Notes, Vendor Advisory
- https://security.gentoo.org/glsa/202401-08
- https://security.netapp.com/advisory/ntap-20221209-0002/Broken Link, Third Party Advisory
- https://www.openwall.com/lists/oss-security/2022/01/24/2Exploit, Mailing List, Patch, Third Party Advisory
- http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.htmlThird Party Advisory
- http://seclists.org/fulldisclosure/2022/Dec/4Mailing List, Third Party Advisory
- http://www.openwall.com/lists/oss-security/2022/11/30/2Mailing List, Third Party Advisory
- https://access.redhat.com/security/cve/CVE-2021-3996Issue Tracking, Third Party Advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=2024628Issue Tracking, Patch, Third Party Advisory
- https://github.com/util-linux/util-linux/commit/166e87368ae88bf31112a30e078cceae637f4cdbPatch, Third Party Advisory
- https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotesRelease Notes, Vendor Advisory
- https://security.gentoo.org/glsa/202401-08
- https://security.netapp.com/advisory/ntap-20221209-0002/Broken Link, Third Party Advisory
- https://www.openwall.com/lists/oss-security/2022/01/24/2Exploit, Mailing List, Patch, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.