Vulnerability Details 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. 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.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.002
EPSS Ranking 46.0%
CVSS Severity
CVSS v3 Score 5.5
References
- http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html
- http://seclists.org/fulldisclosure/2022/Dec/4
- http://www.openwall.com/lists/oss-security/2022/11/30/2
- https://access.redhat.com/security/cve/CVE-2021-3996
- https://bugzilla.redhat.com/show_bug.cgi?id=2024628
- https://github.com/util-linux/util-linux/commit/166e87368ae88bf31112a30e078cceae637f4cdb
- https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotes
- https://security.gentoo.org/glsa/202401-08
- https://security.netapp.com/advisory/ntap-20221209-0002/
- https://www.openwall.com/lists/oss-security/2022/01/24/2
- http://packetstormsecurity.com/files/170176/snap-confine-must_mkdir_and_open_with_perms-Race-Condition.html
- http://seclists.org/fulldisclosure/2022/Dec/4
- http://www.openwall.com/lists/oss-security/2022/11/30/2
- https://access.redhat.com/security/cve/CVE-2021-3996
- https://bugzilla.redhat.com/show_bug.cgi?id=2024628
- https://github.com/util-linux/util-linux/commit/166e87368ae88bf31112a30e078cceae637f4cdb
- https://mirrors.edge.kernel.org/pub/linux/utils/util-linux/v2.37/v2.37.3-ReleaseNotes
- https://security.gentoo.org/glsa/202401-08
- https://security.netapp.com/advisory/ntap-20221209-0002/
- https://www.openwall.com/lists/oss-security/2022/01/24/2
Products affected by CVE-2021-3996
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cpe:2.3:a:kernel:util-linux:2.34
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cpe:2.3:a:kernel:util-linux:2.35
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cpe:2.3:a:kernel:util-linux:2.35.1
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cpe:2.3:a:kernel:util-linux:2.35.2
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cpe:2.3:a:kernel:util-linux:2.36
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cpe:2.3:a:kernel:util-linux:2.36.1
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cpe:2.3:a:kernel:util-linux:2.36.2
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cpe:2.3:a:kernel:util-linux:2.37
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cpe:2.3:a:kernel:util-linux:2.37.1
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cpe:2.3:a:kernel:util-linux:2.37.2
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cpe:2.3:o:fedoraproject:fedora:35