For more than a decade, OpenBSD has had only two officially disclosed bugs that could be considered remotely exploitable. In this presentation, Alfredo Ortega will provide a detailed look at one of those two rare bugs: the IPv6 mbuf overflow he discovered earlier in 2007. Ortega will provide an in-depth view of the process of developing a remote exploit for the bug, analyzing various exploitation techniques, and implementing kernel shellcode that disables the defenses of the operating system and installs a privileged user-mode process.