In verify_emsa_pkcs1_signature() in gmp_rsa_public_key.c in the gmp plugin in strongSwan 4.x and 5.x before 5.7.0, the RSA implementation based on GMP does not reject excess data in the digestAlgorithm.parameters field during PKCS#1 v1.5 signature verification. Consequently, a remote attacker can forge signatures when small public exponents are being used, which could lead to impersonation when only an RSA signature is used for IKEv2 authentication. This is a variant of CVE-2006-4790 and CVE-2014-1568.
In stroke_socket.c in strongSwan before 5.6.3, a missing packet length check could allow a buffer underflow, which may lead to resource exhaustion and denial of service while reading from the socket.
The gmp plugin in strongSwan before 5.6.0 allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted RSA signature.
The gmp plugin in strongSwan before 5.5.3 does not properly validate RSA public keys before calling mpz_powm_sec, which allows remote peers to cause a denial of service (floating point exception and process crash) via a crafted certificate.
The ASN.1 parser in strongSwan before 5.5.3 improperly handles CHOICE types when the x509 plugin is enabled, which allows remote attackers to cause a denial of service (infinite loop) via a crafted certificate.
The server implementation of the EAP-MSCHAPv2 protocol in the eap-mschapv2 plugin in strongSwan 4.2.12 through 5.x before 5.3.4 does not properly validate local state, which allows remote attackers to bypass authentication via an empty Success message in response to an initial Challenge message.
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.
Buffer overflow in the atodn function in strongSwan 2.0.0 through 4.3.4, 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.
The GMP Plugin in strongSwan 4.2.0 through 4.6.3 allows remote attackers to bypass authentication via a (1) empty or (2) zeroed RSA signature, aka "RSA signature verification vulnerability."