CVE-2019-15793 Information

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 Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Reference

https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=3644b9d5688da86f18e017c9c580b75cf52927bb https://usn.ubuntu.com/usn/usn-4183-1 https://usn.ubuntu.com/usn/usn-4184-1

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

CHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

8.8