The ikev2parentinI1outR1 function in pluto/ikev2parent.c in libreswan before 3.7 allows remote attackers to cause a denial of service (restart) via an IKEv2 I1 notification without a KE payload.
Libreswan 3.7 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.
Buffer overflow in the atodn function in libreswan 3.0 and 3.1, when Opportunistic Encryption is enabled and an RSA key is being used, allows remote attackers to cause a denial of service (pluto IKE daemon crash) and possibly execute arbitrary code via crafted DNS TXT records. NOTE: this might be the same vulnerability as CVE-2013-2053 and CVE-2013-2054.