pfSense before 2.1.4 allows remote authenticated users to execute arbitrary commands via (1) the hostname value to diag_dns.php in a Create Alias action, (2) the smartmonemail value to diag_smart.php, or (3) the database value to status_rrd_graph_img.php.
https://www.exploit-db.com/exploits/43560/
https://pfsense.org/security/advisories/pfSense-SA-14_10.webgui.asc