The IPv6 SCTP implementation in net/sctp/ipv6.c in the Linux kernel through 3.11.1 uses data structures and function calls that do not trigger an intended configuration of IPsec encryption, which allows remote attackers to obtain sensitive information by sniffing the network.
http://rhn.redhat.com/errata/RHSA-2013-1490.html
https://bugzilla.redhat.com/show_bug.cgi?id=1007872
https://github.com/torvalds/linux/commit/95ee62083cb6453e056562d91f597552021e6ae7
http://www.openwall.com/lists/oss-security/2013/09/13/3
http://www.ubuntu.com/usn/USN-2019-1
http://www.ubuntu.com/usn/USN-2021-1
http://www.ubuntu.com/usn/USN-2022-1
http://www.ubuntu.com/usn/USN-2024-1
http://www.ubuntu.com/usn/USN-2038-1
http://www.ubuntu.com/usn/USN-2039-1
http://www.ubuntu.com/usn/USN-2041-1
http://www.ubuntu.com/usn/USN-2045-1