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."
https://exchange.xforce.ibmcloud.com/vulnerabilities/76013
http://www.strongswan.org/blog/2012/05/31/strongswan-4.6.4-released-%28cve-2012-2388%29.html
http://www.securitytracker.com/id?1027110
http://www.securityfocus.com/bid/53752
http://www.debian.org/security/2012/dsa-2483
http://secunia.com/advisories/55051
http://secunia.com/advisories/49370
http://secunia.com/advisories/49336
http://secunia.com/advisories/49315
http://lists.opensuse.org/opensuse-security-announce/2012-06/msg00002.html