The Internet Key Exchange version 1 (IKEv1) implementation in Openswan 2 (openswan-2) before 2.4.4, and freeswan in SUSE LINUX 9.1 before 2.04_1.5.4-1.23, allow remote attackers to cause a denial of service via (1) a crafted packet using 3DES with an invalid key length, or (2) unspecified inputs when Aggressive Mode is enabled and the PSK is known, as demonstrated by the PROTOS ISAKMP Test Suite for IKEv1.