We will be presenting a number of previously undisclosed network-related design errors, ranging from data-link-layer bugs in Ethernet-drivers across issues in TCP/IP stacks all the way up to communication infrastructure components on layer 5. Our focus is on subtle mistakes, which do not fall into the memory-corruption category and yet in combination provide an attacker with a powerful bag of tricks.

Built around a fictional average company network, we will tell the story of an attack making use of subtle bugs across the layers all of which are as of yet undisclosed. This will include a bug in an Ethernet-driver, which allows an attacker to bypass MAC- and IP-based filters, bugs in TCP-implementations that are assumed to be fixed but aren't, a web-cache which confuses itself and an instant-messenger, which was fooled by the protocol specification.

All of these bugs share a common property: They are a consequence of insecure design and not of insecure coding-practices.