Avi Alkalay nslookup.cgi program, dated 16 June 2002, allows remote attackers to execute arbitrary commands via shell metacharacters in the query parameter.
https://exchange.xforce.ibmcloud.com/vulnerabilities/22354
http://www.vupen.com/english/advisories/2005/1809
http://www.securityfocus.com/bid/14893
http://www.cirt.net/advisories/alkalay.shtml