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 use-after-free flaw was found in the way Openswan"s pluto IKE daemon used cryptographic helpers. A remote, authenticated attacker could send a specially-crafted IKE packet that would crash the pluto daemon. This issue only affected SMP systems that have the cryptographic helpers enabled. The helpers are disabled by default on Red Hat Enterprise Linux 5, but enabled by default on Red Hat Enterprise Linux 6. Red Hat would like to thank the Openswan project for reporting this issue. Upstream acknowledges Petar Tsankov, Mohammad Torabi Dashti and David Basin of the information security group at ETH Zurich as the original reporters. All users of openswan are advised to upgrade to these updated packages, which contain a backported patch to correct this issue. After installing this update, the ipsec service will be restarted automatically.