BRU backup software allows local users to append data to arbitrary files by specifying an alternate configuration file with the BRUEXECLOG environmental variable.
https://exchange.xforce.ibmcloud.com/vulnerabilities/4644
http://www.securityfocus.com/bid/1321
http://www.calderasystems.com/support/security/advisories/CSSA-2000-018.0.txt
http://archives.neohapsis.com/archives/bugtraq/2000-06/0013.html