Format string vulnerability in the AXIMilter module in AXIGEN Mail Server 5.0.2 allows remote attackers to execute arbitrary code via format string specifiers in the CNHO command.
https://www.exploit-db.com/exploits/4947
https://exchange.xforce.ibmcloud.com/vulnerabilities/39803
http://www.vupen.com/english/advisories/2008/0237
http://www.securityfocus.com/archive/1/486722/100/0/threaded