CVE-2021-3996
MEDIUMDescription
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.
How to fix
Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.
CVSS v3 Vector
Exploitability
Impact
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Exploit Intelligence
Moderate risk: more likely to be exploited than 46% of all known CVEs.
References
Related Vulnerabilities
Other CWE-552 vulnerabilities, ordered by exploit likelihood. View all
| CVE | Severity | CVSS | EPSS | Exploited | Fix |
|---|---|---|---|---|---|
| CVE-2020-17519 | High | 7.5 | 98% | KEV | Fix |
| CVE-2025-11371 | High | 7.5 | 92% | KEV | Fix |
| CVE-2023-50164 | Critical | 9.8 | 81% | - | Fix |
| CVE-2016-3715 | Medium | 5.5 | 75% | KEV | Fix |
| CVE-2020-15175 | High | 7.4 | 71% | - | Fix |
| CVE-2021-39316 | High | 7.5 | 67% | - | - |
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Markdown
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Start freeThis product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.