pt_chown in GNU C Library (aka glibc or libc6) before 2.18 does not properly check permissions for tty files, which allows local users to change the permission on the files and obtain access to arbitrary pseudo-terminals by leveraging a FUSE file system.
http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00019.html
http://lists.opensuse.org/opensuse-security-announce/2016-02/msg00036.html
http://secunia.com/advisories/55113
http://www.mandriva.com/security/advisories?name=MDVSA-2013:283
http://www.ubuntu.com/usn/USN-2985-1
http://www.ubuntu.com/usn/USN-2985-2
https://bugzilla.redhat.com/show_bug.cgi?id=976408
https://security.gentoo.org/glsa/201503-04