The CVE-2021-3493 is an Ubuntu-specific issue in the overlayfs file system in the Linux kernel where there is a lack of proper validation of the application file system capabilities to user namespaces. A local attacker could use this to gain elevated privileges, due to a patch carried in Ubuntu to allow unprivileged overlayfs mounts.
- Understanding important key points used throughout the paper
- The severity and scope of impact of this vulnerability
- Learning about the mitigations for different Ubuntu versions
- Setting up the lab environment and demonstrating the exploitation method