Javier Fernandez-Sanguino Pena noticed that the pwmconfig script created temporary files in an insecure manner. This could allow a symlink attack to create or overwrite arbitrary files with full root privileges since pwmconfig is usually executed by root.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/39562/USN-172-1.txt
Source: https://packetstormsecurity.com/files/39562/Ubuntu-Security-Notice-172-1.html