Format string vulnerability in the msg command (cat_message function in msg.c) in OpenFTPD 0.30.2 and earlier allows remote authenticated users to execute arbitrary code via format string specifiers in the message argument.
https://exchange.xforce.ibmcloud.com/vulnerabilities/16843
http://www.openftpd.org:9673/openftpd
http://secunia.com/advisories/12174
http://archives.neohapsis.com/archives/bugtraq/2004-07/0350.html