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.
| ID | Name | Tiering | Description | NIST Rev5 | ISO 27001 | Onboard SV | Ground | |
| CM0039 | Least Privilege | Employ the principle of least privilege, allowing only authorized processes which are necessary to accomplish assigned tasks in accordance with system functions. Ideally maintain a separate execution domain for each executing process. | AC-2 AC-3(13) AC-3(15) AC-4(2) AC-6 CA-3(6) CM-7 CM-7(5) CM-7(8) PL-8 PL-8(1) SA-17(7) SA-3 SA-4(9) SA-8 SA-8(13) SA-8(14) SA-8(15) SA-8(19) SA-8(3) SA-8(4) SA-8(9) SC-2(2) SC-32(1) SC-49 SC-50 SC-7(29) | A.5.16 A.5.18 A.8.2 A.5.15 A.8.2 A.8.18 A.8.19 A.8.19 A.5.8 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 | ||||
| CM0069 | Process White Listing | Simple process ID whitelisting on the firmware level could impede attackers from instigating unnecessary processes which could impact the spacecraft | CM-11 CM-7(5) PL-8 PL-8(1) SI-10(5) | A.8.19 A.8.19 A.5.8 | ||||
| CM0032 | On-board Intrusion Detection & Prevention | Utilize on-board intrusion detection/prevention system that monitors the mission critical components or systems and audit/logs actions. The IDS/IPS should have the capability to respond to threats (initial access, execution, persistence, evasion, exfiltration, etc.) and it should address signature-based attacks along with dynamic never-before seen attacks using machine learning/adaptive technologies. The IDS/IPS must integrate with traditional fault management to provide a wholistic approach to faults on-board the spacecraft. Spacecraft should select and execute safe countermeasures against cyber-attacks. These countermeasures are a ready supply of options to triage against the specific types of attack and mission priorities. Minimally, the response should ensure vehicle safety and continued operations. Ideally, the goal is to trap the threat, convince the threat that it is successful, and trace and track the attacker — with or without ground support. This would support successful attribution and evolving countermeasures to mitigate the threat in the future. “Safe countermeasures” are those that are compatible with the system’s fault management system to avoid unintended effects or fratricide on the system. | AU-14 AU-2 AU-3 AU-3(1) AU-4 AU-4(1) AU-5 AU-5(2) AU-5(5) AU-6(1) AU-6(4) AU-8 AU-9 AU-9(2) AU-9(3) CA-7(6) CM-11(3) CP-10 CP-10(4) IR-4 IR-4(11) IR-4(12) IR-4(14) IR-4(5) IR-5 IR-5(1) PL-8 PL-8(1) RA-10 RA-3(4) SA-8(21) SA-8(22) SA-8(23) SC-16(2) SC-32(1) SC-5 SC-5(3) SC-7(10) SC-7(9) SI-10(6) SI-16 SI-17 SI-3 SI-3(10) SI-3(8) SI-4 SI-4(1) SI-4(10) SI-4(11) SI-4(13) SI-4(16) SI-4(17) SI-4(2) SI-4(23) SI-4(24) SI-4(25) SI-4(4) SI-4(5) SI-4(7) SI-6 SI-7(17) SI-7(8) | A.8.15 A.8.15 A.8.6 A.8.17 A.5.33 A.8.15 A.8.15 A.5.29 A.5.25 A.5.26 A.5.27 A.5.8 A.5.7 A.8.12 A.8.7 A.8.16 A.8.16 A.8.16 A.8.16 | ||||
| CM0042 | Robust Fault Management | Ensure fault management system cannot be used against the spacecraft. Examples include: safe mode with crypto bypass, orbit correction maneuvers, affecting integrity of telemetry to cause action from ground, or some sort of proximity operation to cause spacecraft to go into safe mode. Understanding the safing procedures and ensuring they do not put the spacecraft in a more vulnerable state is key to building a resilient spacecraft. | CP-2 CP-4(5) IR-3 IR-3(1) IR-3(2) PE-10 PE-11 PE-11(1) PE-14 PL-8 PL-8(1) SA-3 SA-4(5) SA-8 SA-8(13) SA-8(24) SA-8(26) SA-8(3) SA-8(30) SA-8(4) SC-16(2) SC-24 SC-5 SI-13 SI-13(4) SI-17 SI-4(13) SI-4(7) SI-7(5) | 7.5.1 7.5.2 7.5.3 A.5.2 A.5.29 A.8.1 A.7.11 A.7.11 A.7.5 A.7.8 A.7.11 A.5.8 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 A.8.16 | ||||
| CM0044 | Cyber-safe Mode | Provide the capability to enter the spacecraft into a configuration-controlled and integrity-protected state representing a known, operational cyber-safe state (e.g., cyber-safe mode). Spacecraft should enter a cyber-safe mode when conditions that threaten the platform are detected. Cyber-safe mode is an operating mode of a spacecraft during which all nonessential systems are shut down and the spacecraft is placed in a known good state using validated software and configuration settings. Within cyber-safe mode, authentication and encryption should still be enabled. The spacecraft should be capable of reconstituting firmware and software functions to pre-attack levels to allow for the recovery of functional capabilities. This can be performed by self-healing, or the healing can be aided from the ground. However, the spacecraft needs to have the capability to replan, based on equipment still available after a cyber-attack. The goal is for the spacecraft to resume full mission operations. If not possible, a reduced level of mission capability should be achieved. Cyber-safe mode software/configuration should be stored onboard the spacecraft in memory with hardware-based controls and should not be modifiable. | CP-10 CP-10(4) CP-12 CP-2 CP-2(5) IR-3 IR-3(1) IR-3(2) IR-4 IR-4(12) IR-4(3) PE-10 PE10 PL-8 PL-8(1) SA-3 SA-8 SA-8(10) SA-8(12) SA-8(13) SA-8(19) SA-8(21) SA-8(23) SA-8(24) SA-8(26) SA-8(3) SA-8(4) SC-16(2) SC-24 SC-5 SI-11 SI-17 SI-4(7) SI-7(17) SI-7(5) | 7.5.1 7.5.2 7.5.3 A.5.2 A.5.29 A.8.1 A.5.29 A.5.25 A.5.26 A.5.27 A.7.11 A.5.8 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 | ||||
| CM0038 | Segmentation | Identify the key system components or capabilities that require isolation through physical or logical means. Information should not be allowed to flow between partitioned applications unless explicitly permitted by security policy. Isolate mission critical functionality from non-mission critical functionality by means of an isolation boundary (implemented via partitions) that controls access to and protects the integrity of, the hardware, software, and firmware that provides that functionality. Enforce approved authorizations for controlling the flow of information within the spacecraft and between interconnected systems based on the defined security policy that information does not leave the spacecraft boundary unless it is encrypted. Implement boundary protections to separate bus, communications, and payload components supporting their respective functions. | AC-4 AC-4(14) AC-4(2) AC-4(24) AC-4(26) AC-4(31) AC-4(32) AC-4(6) AC-6 CA-3 CA-3(7) PL-8 PL-8(1) SA-3 SA-8 SA-8(13) SA-8(15) SA-8(18) SA-8(3) SA-8(4) SA-8(9) SC-16(3) SC-2(2) SC-3 SC-3(4) SC-32 SC-32(1) SC-39 SC-4 SC-49 SC-50 SC-6 SC-7(20) SC-7(21) SC-7(29) SC-7(5) SI-17 SI-4(7) | A.5.14 A.8.22 A.8.23 A.5.15 A.8.2 A.8.18 A.5.14 A.8.21 A.5.8 A.5.2 A.5.8 A.8.25 A.8.31 A.8.27 A.8.28 | ||||