CVE-2021-3493 Ubuntu OverlayFS Local Privesc (Interactive Bash Shell & Execute Command Entered)
Ubuntu OverlayFS Local Privesc
"Ubuntu specific issue in the overlayfs file system in the Linux kernel where it did not properly validate the application of file system capabilities with respect 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." - Ubuntu Security
Fixed in Linux 5.11
checklist: https://ubuntu.com/security/CVE-2021-3493
gcc exploit.c -o exploit
chmod +x exploit
./exploit shell|command