Github GitHub - briskets/CVE-2021-3493: Ubuntu OverlayFS Local Privesc
source link: https://github.com/briskets/CVE-2021-3493
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CVE-2021-3493
Ubuntu OverlayFS Local Privesc
Affected Versions
- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS
- Ubuntu 14.04 ESM
Usage
gcc exploit.c -o exploit
chmod +x exploit
./exploit
Description
"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
References
Disclaimer
I am not the author of this exploit. I have not made any modifications to the PoC found here: https://ssd-disclosure.com/ssd-advisory-overlayfs-pe/.
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