The in-memory certificate cache in strongSwan before 5.9.4 has a remote integer overflow upon receiving many requests with different certificates to fill the cache and later trigger the replacement of cache entries. The code attempts to select a less-often-used cache entry by means of a random number generator, but this is not done correctly. Remote code execution might be a slight possibility.

The asn1length function in strongSwan 2.8 before 2.8.11, 4.2 before 4.2.17, and 4.3 before 4.3.3 does not properly handle X.509 certificates with crafted Relative Distinguished Names (RDNs), which allows remote attackers to cause a denial of service (pluto IKE daemon crash) via malformed ASN.1 data. NOTE: this is due to an incomplete fix for CVE-2009-2185.

The ASN.1 parser (pluto/asn1.c, libstrongswan/asn1/asn1.c, libstrongswan/asn1/asn1parser.c) in (a) strongSwan 2.8 before 2.8.10, 4.2 before 4.2.16, and 4.3 before 4.3.2; and (b) openSwan 2.6 before 2.6.22 and 2.4 before 2.4.15 allows remote attackers to cause a denial of service (pluto IKE daemon crash) via an X.509 certificate with (1) crafted Relative Distinguished Names (RDNs), (2) a crafted UTCTIME string, or (3) a crafted GENERALIZEDTIME string.

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."

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.