Openswan 2.6.39 and earlier allows remote attackers to cause a denial of service (NULL pointer dereference and IKE daemon restart) via IKEv2 packets that lack expected payloads.

The pluto IKE daemon in Openswan and Strongswan IPsec 2.6 before 2.6.21 and 2.4 before 2.4.14, and Strongswan 4.2 before 4.2.14 and 2.8 before 2.8.9, allows remote attackers to cause a denial of service (daemon crash and restart) via a crafted (1) RUTHERE or (2) RUTHEREACK Dead Peer Detection (DPD) IPsec IKE Notification message that triggers a NULL pointer dereference related to inconsistent ISAKMP state and the lack of a phase2 state association in DPD.

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 2.041.5.4-1.23, 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.