WEB-DAV Linux File System (davfs2) 1.4.6 and 1.4.7 allow local users to gain privileges via unknown attack vectors in (1) kernel_interface.c and (2) mount_davfs.c, related to the "system" function.
https://security.gentoo.org/glsa/201612-02
http://www.securityfocus.com/bid/62445
http://www.debian.org/security/2013/dsa-2765
http://seclists.org/oss-sec/2013/q3/627