Serv-U 7.0.0.1 through 7.3, including 7.2.0.1, allows remote authenticated users to cause a denial of service (CPU consumption) via a crafted stou command, probably related to MS-DOS device names, as demonstrated using "con:1".
https://www.exploit-db.com/exploits/6660
https://exchange.xforce.ibmcloud.com/vulnerabilities/45652
http://www.vupen.com/english/advisories/2008/2746