CVE-2021-3493
high-risk
Published 2021-04-17
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.
Do I need to act?
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76.4% chance of exploitation in next 30 days
EPSS score — higher than 24% of all CVEs
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CISA KEV: actively exploited in the wild
On the Known Exploited Vulnerabilities catalog — federal agencies must patch
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
8
CVSS 8.8/10
High
LOCAL
/ LOW complexity
Affected Products (2)
Affected Vendors
References (13)
Press/Media Coverage
http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Esc...
Vendor Advisory
https://ubuntu.com/security/notices/USN-4917-1
Press/Media Coverage
http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Esc...
Vendor Advisory
https://ubuntu.com/security/notices/USN-4917-1
US Government Resource
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-...
61
/ 100
high-risk
Severity
27/34 · High
Exploitability
27/34 · High
Exposure
7/34 · Low