The overlayfs implementation in the linux (aka Linux kernel) package before 3.19.0-21.21 in Ubuntu through 15.04 does not properly check permissions for file creation in the upper filesystem directory, which allows local users to obtain root access by leveraging a configuration in which overlayfs is permitted in an arbitrary mount namespace.
Source: https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-1328
Reference (s):
- BID:75206
- URL: http://www.securityfocus.com/bid/75206
- https://people.canonical.com/~ubuntu-security/cve/2015/CVE-2015-1328.html
- https://security-tracker.debian.org/tracker/CVE-2015-1328
- EXPLOIT-DB:37292