Published: 02/05/2016 Updated: 12/08/2016
CVSS v2 Base Score: 3.6 | Impact Score: 4.9 | Exploitability Score: 3.9
CVSS v3 Base Score: 6.1 | Impact Score: 4.2 | Exploitability Score: 1.8
VMScore: 321
Vector: AV:L/AC:L/Au:N/C:P/I:P/A:N

Vulnerability Summary

fs/namespace.c in the Linux kernel prior to 4.0.2 processes MNT_DETACH umount2 system calls without verifying that the MNT_LOCKED flag is unset, which allows local users to bypass intended access restrictions and navigate to filesystem locations beneath a mount by calling umount2 within a user namespace.

Vendor Advisories

It was found that unsharing a mount namespace could allow a user to see data beneath their restricted namespace ...