Check Point VPN-1 R55, R65, and other versions, when Port Address Translation (PAT) is used, allows remote attackers to discover intranet IP addresses via a packet with a small TTL, which triggers an ICMP_TIMXCEED_INTRANS (aka ICMP time exceeded in-transit) response containing an encapsulated IP packet with an intranet address, as demonstrated by a TCP packet to the firewall management server on port 18264.

Check Point VPN-1 Power/UTM, with NGX R60 through R65 and NG AI R55 software, allows remote authenticated users to cause a denial of service (site-to-site VPN tunnel outage), and possibly intercept network traffic, by configuring the local RFC1918 IP address to be the same as one of this tunnel's endpoint RFC1918 IP addresses, and then using SecuRemote to connect to a network interface at the other endpoint.

The Internet Key Exchange version 1 (IKEv1) implementation in Check Point products allows remote attackers to cause a denial of service via certain crafted IKE packets, as demonstrated by the PROTOS ISAKMP Test Suite for IKEv1. NOTE: due to the lack of details in the advisory, it is unclear which of CVE-2005-3666, CVE-2005-3667, and/or CVE-2005-3668 this issue applies to.

Buffer overflow in the ISAKMP functionality for Check Point VPN-1 and FireWall-1 NG products, before VPN-1/FireWall-1 R55 HFA-03, R54 HFA-410 and NG FP3 HFA-325, or VPN-1 SecuRemote/SecureClient R56, may allow remote attackers to execute arbitrary code during VPN tunnel negotiation.