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CVE-2021-3493

HIGHCISA KEV

8.8

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.

Details CVE

Score CVSS v3.18.8

SeveriteHIGH

Vecteur CVSSCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Vecteur d'attaqueLOCAL

ComplexiteLOW

Privileges requisLOW

Interaction utilisateurNONE

Publie4/17/2021

Derniere modification10/28/2025

Sourcekev

Observations honeypot0

CISA KEV

FournisseurLinux

ProduitKernel

Nom vulnerabiliteLinux Kernel Privilege Escalation Vulnerability

Date ajout KEV2022-10-20

Date limite remediation2022-11-10

Utilise dans ransomwareUnknown

Produits affectes

canonical:ubuntu_linux

Faiblesses (CWE)

CWE-270CWE-863

References

http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html(security@ubuntu.com)

http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html(security@ubuntu.com)

http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html(security@ubuntu.com)

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52(security@ubuntu.com)

https://ubuntu.com/security/notices/USN-4917-1(security@ubuntu.com)

https://www.openwall.com/lists/oss-security/2021/04/16/1(security@ubuntu.com)

http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html(af854a3a-2127-422b-91ae-364da2661108)

http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html(af854a3a-2127-422b-91ae-364da2661108)

http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html(af854a3a-2127-422b-91ae-364da2661108)

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7c03e2cda4a584cadc398e8f6641ca9988a39d52(af854a3a-2127-422b-91ae-364da2661108)

https://ubuntu.com/security/notices/USN-4917-1(af854a3a-2127-422b-91ae-364da2661108)

https://www.openwall.com/lists/oss-security/2021/04/16/1(af854a3a-2127-422b-91ae-364da2661108)

https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-3493(134c704f-9b21-4f2e-91b3-4a467353bcc0)

Correlations IOC

Aucune correlation enregistree

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