Buffer overflow in Change passwd 3.1 (chpasswd) SquirrelMail plugin allows local users to execute arbitrary code via long command line arguments.
https://exchange.xforce.ibmcloud.com/vulnerabilities/24258
http://www.squirrelmail.org/plugin_view.php?id=117
http://www.securityfocus.com/archive/1/422414/100/0/threaded