Openswan is a free implementation of Internet Protocol Security and Internet Key Exchange . IPsec uses strong cryptography to provide both authentication and encryption services. These services allow you to build secure tunnels through untrusted networks. Everything passing through the untrusted network is encrypted by the IPsec gateway machine, and decrypted by the gateway at the other end of the tunnel. The resulting tunnel is a virtual private network . Multiple insufficient input validation flaws were found in the way Openswan"s pluto IKE daemon processed some fields of X.509 certificates. A remote attacker could provide a specially-crafted X.509 certificate that would crash the pluto daemon. All users of openswan are advised to upgrade to these updated packages, which contain a backported patch to correct these issues. After installing this update, the ipsec service will be restarted automatically.