The Internet Key Exchange version 1 (IKEv1) implementation in Stonesoft StoneGate Firewall before 2.6.1 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 Stonesoft advisory, it is unclear which of CVE-2005-3666, CVE-2005-3667, and/or CVE-2005-3668 this issue applies to.