Check Point FireWall-1 contains a flaw that may allow a remote attacker to crash the firewall and cause it to "fail open". The issue is due to a flaw in the Getkey handling (inter-module communication protocol) which may allow for a buffer overflow. If an attacker supplies a specially crafted response to a Getkey request, they can crash the firewall. With such a request, the firewall daemon terminates leaving the ruleset enforcement enabled, but allows them to bypass any restriction outside of the standard policy enforcement.
Upgrade to version 4.0 SP7, 4.1 SP2 or higher, as it has been reported to fix this vulnerability. An upgrade is required as there are no known workarounds.