Crosslink via Compromised Neighbor - IA-0003

Where spacecraft exchange data over inter-satellite links (RF or optical), a compromise on one vehicle can become a bridgehead to others. Threat actors exploit crosslink trust: shared routing, time distribution, service discovery, or gateway functions that forward commands and data between vehicles and ground. With knowledge of crosslink framing, addressing, and authentication semantics, an adversary can craft traffic that appears to originate from a trusted neighbor, injecting control messages, malformed service advertisements, or payload tasking that propagates across the mesh. In tightly coupled constellations, crosslinks may terminate on gateways that also touch the C&DH or payload buses, providing additional pivot opportunities. Because crosslink traffic is expected and often high volume, attacker activity can be timed to blend with synchronization intervals, ranging exchanges, or scheduled data relays.