Vulnerability Description
In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, several locations which shift ids translate user/group ids before performing operations in the lower filesystem were translating them into init_user_ns, whereas they should have been translated into the s_user_ns for the lower filesystem. This resulted in using ids other than the intended ones in the lower fs, which likely did not map into the shifts s_user_ns. A local attacker could use this to possibly bypass discretionary access control permissions.
CVSS Score
MEDIUM
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux Kernel | 5.0 |
| Canonical | Ubuntu Linux | 18.04 |
Related Weaknesses (CWE)
References
- https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?Mailing ListPatchThird Party Advisory
- https://usn.ubuntu.com/usn/usn-4183-1Third Party Advisory
- https://usn.ubuntu.com/usn/usn-4184-1Third Party Advisory
- https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?Mailing ListPatchThird Party Advisory
- https://usn.ubuntu.com/usn/usn-4183-1Third Party Advisory
- https://usn.ubuntu.com/usn/usn-4184-1Third Party Advisory
FAQ
What is CVE-2019-15793?
CVE-2019-15793 is a vulnerability with a CVSS score of 6.5 (MEDIUM). In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, several locations which shift ids translate user/group ids before performing operations in the lo...
How severe is CVE-2019-15793?
CVE-2019-15793 has been rated MEDIUM with a CVSS base score of 6.5/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2019-15793?
Check the references section above for vendor advisories and patch information. Affected products include: Linux Linux Kernel, Canonical Ubuntu Linux.