Hacking AFDX or Not - A Primer for Flight Control Systems Security

The talk introduces AFDX (ARINC 664), the Ethernet-based network Airbus developed for aircraft such as the A380, and compares it with the older ARINC 429 and 629 buses. The presenters explain why standard tooling struggles with it: traffic is unidirectional, travels over defined virtual links, and has meaning encoded in its MAC and IP addresses. Switches do not learn addresses or route packets, so ARP, DHCP and Nmap-style discovery do not behave as they would on a normal network.

To understand the switch's behaviour, the team wrote brute-force tools that find accepted virtual links and payload sizes, and a fuzzer that changed header fields one at a time. They found that the switch filters almost entirely on the destination address and packet size, and that it enforces the configuration supplied by the operator. They also built a Wireshark dissector and a kernel-level shim that rewrites headers so existing data-loading software can send traffic. The main concern was the 615A data-loading protocol, because a malicious firmware or configuration image could cause serious damage, and older systems rely on CRC rather than signatures or secure boot.

The speakers reported no new vulnerabilities in the switch, which matched its documented configuration. Their takeaway is that the protocol's segregation and obscurity make conventional attacks hard, but offer no authentication or encryption. They also caution that their findings come from a single airframe, so the switch's prevalence across aircraft remains unconfirmed.