spell-check-logic.cgi in Moodle 1.8.2 allows local users to overwrite arbitrary files via a symlink attack on the (1) /tmp/spell-check-debug.log, (2) /tmp/spell-check-before, or (3) /tmp/spell-check-after temporary file.
https://exchange.xforce.ibmcloud.com/vulnerabilities/46708
http://www.securityfocus.com/bid/32402
http://www.debian.org/security/2009/dsa-1724