Format string vulnerability in the SMTP server for McAfee WebShield 4.5 MR2 and earlier allows remote attackers to execute arbitrary code via format strings in the domain name portion of a destination address, which are not properly handled when a bounce message is constructed.
https://exchange.xforce.ibmcloud.com/vulnerabilities/25621
http://www.vupen.com/english/advisories/2006/1219
http://www.securityfocus.com/bid/16742
http://www.securityfocus.com/archive/1/429812/100/0/threaded
http://securitytracker.com/id?1015861