strongSwan 4.3.0 through 5.x before 5.3.2 and strongSwan VPN Client before 1.4.6, when using EAP or pre-shared keys for authenticating an IKEv2 connection, does not enforce server authentication restrictions until the entire authentication process is complete, which allows remote servers to obtain credentials by using a valid certificate and then reading the responses.
strongSwan 4.5.x through 5.2.x before 5.2.1 allows remote attackers to cause a denial of service (invalid pointer dereference) via a crafted IKEv2 Key Exchange (KE) message with Diffie-Hellman (DH) group 1025.
strongSwan before 5.1.2 allows remote attackers to cause a denial of service (NULL pointer dereference and IKE daemon crash) via a crafted ID_DER_ASN1_DN ID payload.
IKEv2 in strongSwan 4.0.7 before 5.1.3 allows remote attackers to bypass authentication by rekeying an IKE_SA during (1) initiation or (2) re-authentication, which triggers the IKE_SA state to be set to established.
The compare_dn function in utils/identification.c in strongSwan 4.3.3 through 5.1.1 allows (1) remote attackers to cause a denial of service (out-of-bounds read, NULL pointer dereference, and daemon crash) or (2) remote authenticated users to impersonate arbitrary users and bypass access restrictions via a crafted ID_DER_ASN1_DN ID, related to an "insufficient length check" during identity comparison.
strongSwan 5.0.2 through 5.1.0 allows remote attackers to cause a denial of service (NULL pointer dereference and charon daemon crash) via a crafted IKEv1 fragmentation packet.