fence_manual, as used in fence 2.02.00-r1 and possibly cman, allows local users to modify arbitrary files via a symlink attack on the fence_manual.fifo temporary file.
https://exchange.xforce.ibmcloud.com/vulnerabilities/45953
http://www.ubuntu.com/usn/USN-875-1
http://www.openwall.com/lists/oss-security/2008/10/16/1