CVE-2021-3493
CVSS v3
7.8
HIGH
EPSS Score
76.8 %
exploit probability
CISA KEV
Yes
known exploited
Exploitation
—
SSVC status
Description
The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.
CISA Known Exploited Vulnerability
- Date Added
- 2022-10-20
- Patch Due Date
- 2022-11-10
- Ransomware Use
- Unknown
Technical details
- Published
- 2021-04-17
Frequently asked questions
What is CVE-2021-3493?
The overlayfs implementation in the linux kernel did not properly validate with respect to user namespaces the setting of file capabilities on files in an underlying file system. Due to the combination of unprivileged user namespaces along with a patch carried in the Ubuntu kernel to allow unprivileged overlay mounts, an attacker could use this to gain elevated privileges.
Is CVE-2021-3493 actively exploited?
Yes. CVE-2021-3493 is on the CISA Known Exploited Vulnerabilities (KEV) catalog, meaning it has been confirmed as actively exploited in the wild. CISA requires federal agencies to patch by 2022-11-10.
What is the CVSS score for CVE-2021-3493?
CVE-2021-3493 has a CVSS v3 base score of 7.8 (HIGH severity).
Is CVE-2021-3493 affecting your environment?
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