HIGH CISA KEV

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
10/20/2022
Patch Due Date
11/10/2022
Ransomware Use
Unknown

Technical details

Published
4/17/2021

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 11/10/2022.

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?

Use isMalicious to check if any of your IPs or domains are associated with this vulnerability's IOCs.