Detections
Analytics
CVE-2021-3493
high
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.
References
https://www.openwall.com/lists/oss-security/2021/04/16/1
http://packetstormsecurity.com/files/162866/Ubuntu-OverlayFS-Local-Privilege-Escalation.html
https://github.com/WhatsWrongAndWhy/CVE-2021-3493
https://github.com/Ayham-Megdadi/Zero-Day-Legacy
https://github.com/antinest/CVEs
https://github.com/KaraZajac/SKELETONKEY
https://github.com/iqbalhussainas/OverlayFS-LPE-Exploit
https://github.com/George-Yanni/DeepRoot
https://github.com/Sornphut/OverlayFS---CVE-2021-3493
https://github.com/iamz24/CVE-2021-3493_CVE-2022-3357
https://github.com/derek-turing/CVE-2021-3493
https://github.com/inspiringz/CVE-2021-3493
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2021-3493
https://ubuntu.com/security/notices/USN-4917-1
http://packetstormsecurity.com/files/165151/Ubuntu-Overlayfs-Local-Privilege-Escalation.html
http://packetstormsecurity.com/files/162434/Kernel-Live-Patch-Security-Notice-LSN-0076-1.html