The seed generation mechanism in the inter-module S/Key authentication mechanism in Check Point VPN-1/FireWall-1 4.1 and earlier allows remote attackers to bypass authentication via a brute force attack, aka "One-time (s/key) Password Authentication."
https://exchange.xforce.ibmcloud.com/vulnerabilities/5137
http://www.checkpoint.com/techsupport/alerts/list_vun.html#One-time_Password