Scheduling Algorithm - EX-0012.05
Definition
Spacecraft typically rely on real-time scheduling, fixed-priority or deadline/periodic schemes, driven by timers, tick sources, and per-task parameters. Threat actors target these parameters and associated tables to skew execution order and timing. Edits may change priorities, periods, or deadlines; adjust CPU budgets and watchdog thresholds; alter ready-queue disciplines; or reconfigure timer tick rates and clock sources. They may also modify task affinities, message-queue depths, and interrupt masks so preemption and latency characteristics shift. Small changes can have large effects: high-rate control loops see added jitter, estimator updates miss deadlines, command/telemetry handling starves, or low-priority maintenance tasks monopolize cores due to mis-set periods. Manipulated schedules can create intermittent, state-dependent malfunctions that are hard to distinguish from environmental load. The essence of the technique is to weaponize time, reshaping when work happens so that otherwise correct code produces unsafe or exploitable behavior.
D3FEND Inferred Relationships