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. A NULL pointer dereference flaw was discovered in the way Openswan"s IKE daemon processed IKEv2 payloads. A remote attacker could send specially crafted IKEv2 payloads that, when processed, would lead to a denial of service , possibly causing existing VPN connections to be dropped. All openswan users are advised to upgrade to these updated packages, which contain a backported patch to correct this issue.