WFTPD and WFTPD Pro 2.41 RC12 allows remote attackers to cause a denial of service by sending a long string of unprintable characters.
https://exchange.xforce.ibmcloud.com/vulnerabilities/5194
http://www.wftpd.com/bug_gpf.htm
http://archives.neohapsis.com/archives/bugtraq/2000-08/0488.html