Detection of unexpected high-priority CAN messages (lower message IDs) originating from unauthorized subsystems. This may indicate that a threat actor is injecting high-priority messages to dominate the CAN bus and manipulate subsystem communications.
| ID | Name | Description | |
| EX-0001 | Replay | Replay is the re-transmission of previously captured traffic, over RF links, crosslinks, or internal buses, to elicit the same processing and effects a second time. Adversaries first observe and record authentic exchanges (telecommands, ranging/acquisition frames, housekeeping telemetry acknowledgments, bus messages), then resend them within acceptance conditions that the system recognizes, matching link geometry, timetags, counters, or mode states. The aim can be functional (re-triggering an action such as a mode change), observational (fingerprinting how the vehicle reacts at different states), or disruptive (saturating queues and bandwidth to crowd out legitimate traffic). Because replays preserve valid syntax and often valid context, they can blend with normal operations, especially during periods with reduced monitoring or when counters and windows reset (e.g., handovers, safing entries). On encrypted links, metadata replays (acquisition beacons, schedule requests) may still yield informative responses. | |
| EX-0001.02 | Bus Traffic Replay | Instead of the RF path, the attacker targets internal command/data handling by injecting or retransmitting messages on the spacecraft bus (e.g., 1553, SpaceWire, custom). Because many subsystems act on the latest message or on message rate rather than on uniqueness, a flood of historical yet well-formed frames can consume bandwidth, starve critical publishers, or cause subsystems to perform the same action repeatedly. Secondary effects include stale sensor values being re-consumed, watchdog timers being reset at incorrect intervals, and autonomy rules misclassifying the situation due to out-of-order but valid-looking events. On time-triggered or scheduled buses, replaying at precise offsets can collide with or supersede legitimate messages, steering system state without changing software. The goal is to harness the bus’s determinism, repeating prior internal stimuli to recreate prior effects or to induce resource exhaustion. | |
| EX-0014 | Spoofing | The adversary forges inputs that subsystems treat as trustworthy truth, time tags, sensor measurements, bus messages, or navigation signals, so onboard logic acts on fabricated reality. Because many control loops and autonomy rules assume data authenticity once it passes basic sanity checks, carefully shaped spoofs can trigger mode transitions, safing, actuator commands, or payload behaviors without touching flight code. Spoofing may occur over RF (e.g., GNSS, crosslinks, TT&C beacons), over internal networks/buses (message injection with valid identifiers), or at sensor/actuator interfaces (electrical/optical stimulation that produces plausible readings). Effects range from subtle bias (drifting estimates, skewed calibrations) to acute events (unexpected slews, power reconfiguration, recorder re-indexing), and can also pollute downlinked telemetry or science products so ground controllers interpret a false narrative. The hallmark is that the spacecraft chooses the adversary’s action path because the forged data passes through normal processing chains. | |
| EX-0014.02 | Bus Traffic Spoofing | Here the adversary forges messages on internal command/data paths (e.g., 1553, SpaceWire, CAN, custom). By emitting frames with valid identifiers, addresses, and timing, the attacker can make subscribers accept actuator setpoints, power switch toggles, mode changes, or housekeeping values that originated off-path. Because many consumers act on “latest value wins” or on message cadence, forged traffic can mask real publishers, starve critical topics, or force handlers to execute unintended branches. Gateways that translate between networks amplify impact: a spoofed message on one side can propagate to multiple domains as legitimate payload. Outcomes include misdelivered commands, silent configuration drift, and control loops chasing phantom stimuli, all while bus monitors show protocol-conformant traffic. | |
| LM-0001 | Hosted Payload | The adversary pivots through the host–payload boundary to reach additional subsystems. Hosted payloads exchange power, time, housekeeping, and data with the bus via defined gateways (e.g., SpaceWire, 1553, Ethernet) and often support file services, table loads, and command dictionaries distinct from the host’s. A foothold on the payload can be used to inject traffic through the gateway processor, request privileged services (time/ephemeris distribution, firmware loads), or ride shared backplanes where payload traffic is bridged into C&DH networks. In some designs, payload processes execute on host compute or expose maintenance modes that temporarily widen access, creating paths from the payload into attitude, power, storage, or recorder resources. The movement is transitive: compromise a co-resident unit, then traverse the trusted interface that already exists for mission operations. | |
| LM-0002 | Exploit Lack of Bus Segregation | On flat architectures, where remote terminals, subsystems, and payloads share a common bus with minimal partitioning, any node that can transmit may influence many others. An attacker leverages this by forging message IDs or terminal addresses, replaying actuator/sensor frames, seizing or imitating bus-controller roles, or abusing gateway bridges that forward traffic between links (e.g., 1553↔SpaceWire/CAN). Because consumers often act on the latest valid-looking message, crafted traffic from one compromised device can reconfigure peers, toggle power domains, or write persistent parameters. Weak role enforcement and broadcast semantics allow privilege escalation from a peripheral to effective system-wide influence, turning the shared medium into a highway for further compromise. | |
| LM-0004 | Visiting Vehicle Interface(s) | Docking, berthing, or short-duration attach events create high-trust, high-bandwidth connections between vehicles. During these operations, automatic sequences verify latches, exchange status, synchronize time, and enable umbilicals that carry data and power; maintenance tools may also push firmware or tables across the interface. An attacker positioned on the visiting vehicle can exploit these handshakes and service channels to inject commands, transfer files, or access bus gateways on the host. Because many actions are expected “just after dock,” malicious traffic can ride the same procedures that commission the interface, allowing lateral movement from the visiting craft into the target spacecraft’s C&DH, payload, or support subsystems. | |
| LM-0006 | Launch Vehicle Interface | During integration and ascent, payloads and the launch vehicle exchange power, discrete lines, and data via umbilicals, separation avionics, and shared EGSE networks. Protections can be reduced or heterogeneous because timelines are tight and responsibilities cross organizations. An attacker positioned on either side (vehicle or payload) can use these commissioning links, health/status queries, time distribution, inhibit lines, separation commands, or telemetry gateways, to inject messages, transfer files, or alter configuration that propagates across the interface. Before fairing close and prior to separation, this brief but high-trust coupling provides a route to move from one platform to the other and to seed artifacts that persist after deployment. | |