strongSwan 4.2.6 and earlier allows remote attackers to cause a denial of service (daemon crash) via an IKESAINIT message with a large number of NULL values in a Key Exchange payload, which triggers a NULL pointer dereference for the return value of the mpzexport function in the GNU Multiprecision Library (GMP).

The isasn1 function in strongSwan 4.1.11 through 5.0.4 does not properly validate the return value of the asn1length function, which allows remote attackers to cause a denial of service (segmentation fault) via a (1) XAuth username, (2) EAP identity, or (3) PEM encoded file that starts with a 0x04, 0x30, or 0x31 character followed by an ASN.1 length value that triggers an integer overflow.

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.