Check Point VPN-1/FireWall-1 4.1 and earlier allows remote attackers to redirect FTP connections to other servers ("FTP Bounce") via invalid FTP commands that are processed improperly by FireWall-1, aka "FTP Connection Enforcement Bypass."
https://exchange.xforce.ibmcloud.com/vulnerabilities/5474
http://www.checkpoint.com/techsupport/alerts/list_vun.html#FTP_Connection