Check Point VPN-1/FireWall-1 4.1 and earlier improperly retransmits encapsulated FWS packets, even if they do not come from a valid FWZ client, aka "Retransmission of Encapsulated Packets."
https://exchange.xforce.ibmcloud.com/vulnerabilities/5469
http://www.checkpoint.com/techsupport/alerts/list_vun.html#Retransmission_of