Looking Glass 20040427 allows remote attackers to execute arbitrary commands via shell metacharacters in the DNS lookup query field.
https://exchange.xforce.ibmcloud.com/vulnerabilities/22045
https://euvd.enisa.europa.eu/vulnerability/EUVD-2005-2778
http://www.securityfocus.com/bid/14682
http://secunia.com/advisories/16607/
http://rgod.altervista.org/lookingglass.html