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.

Sources

https://attack.mitre.org/mitigations/M1031/

Best Segment for Countermeasure Deployment

Space Segment

NIST Rev5 Controls

D3FEND Techniques

D3FEND Artifacts

ISO 27001

ID: CM0032

NASA Best Practice Guide: MI-AUTH-01 | MI-AUTH-02 | MI-INTG-01 | MI-DCO-02

ESA Space Shield Mitigation: M1037 | M2064 | M2076 | M2078

Created: 2022/10/19

Last Modified: 2023/11/29

Techniques Addressed by Countermeasure

ID		Name	Description
IA-0003		Crosslink via Compromised Neighbor	Threat actors may compromise a victim spacecraft via the crosslink communications of a neighboring spacecraft that has been compromised. spacecraft in close proximity are able to send commands back and forth. Threat actors may be able to leverage this access to compromise other spacecraft once they have access to another that is nearby.
IA-0006		Compromise Hosted Payload	Threat actors may compromise the target spacecraft hosted payload to initially access and/or persist within the system. Hosted payloads can usually be accessed from the ground via a specific command set. The command pathways can leverage the same ground infrastructure or some host payloads have their own ground infrastructure which can provide an access vector as well. Threat actors may be able to leverage the ability to command hosted payloads to upload files or modify memory addresses in order to compromise the system. Depending on the implementation, hosted payloads may provide some sort of lateral movement potential.
IA-0007		Compromise Ground System	Threat actors may initially compromise the ground system in order to access the target spacecraft. Once compromised, the threat actor can perform a multitude of initial access techniques, including replay, compromising FSW deployment, compromising encryption keys, and compromising authentication schemes. Threat actors may also perform further reconnaissance within the system to enumerate mission networks and gather information related to ground station logical topology, missions ran out of said ground station, birds that are in-band of targeted ground stations, and other mission system capabilities.
	.01	Compromise On-Orbit Update	Threat actors may manipulate and modify on-orbit updates before they are sent to the target spacecraft. This attack can be done in a number of ways, including manipulation of source code, manipulating environment variables, on-board table/memory values, or replacing compiled versions with a malicious one.
	.02	Malicious Commanding via Valid GS	Threat actors may compromise target owned ground systems components (e.g., front end processors, command and control software, etc.) that can be used for future campaigns or to perpetuate other techniques. These ground systems components have already been configured for communications to the victim spacecraft. By compromising this infrastructure, threat actors can stage, launch, and execute an operation. Threat actors may utilize these systems for various tasks, including Execution and Exfiltration.
IA-0008		Rogue External Entity	Threat actors may gain access to a victim spacecraft through the use of a rogue external entity. With this technique, the threat actor does not need access to a legitimate ground station or communication site.
	.01	Rogue Ground Station	Threat actors may gain access to a victim spacecraft through the use of a rogue ground system. With this technique, the threat actor does not need access to a legitimate ground station or communication site.
	.02	Rogue Spacecraft	Threat actors may gain access to a target spacecraft using their own spacecraft that has the capability to maneuver within close proximity to a target spacecraft to carry out a variety of TTPs (i.e., eavesdropping, side-channel, etc.). Since many of the commercial and military assets in space are tracked, and that information is publicly available, attackers can identify the location of space assets to infer the best positioning for intersecting orbits. Proximity operations support avoidance of the larger attenuation that would otherwise affect the signal when propagating long distances, or environmental circumstances that may present interference.
IA-0010		Exploit Reduced Protections During Safe-Mode	Threat actors may take advantage of the victim spacecraft being in safe mode and send malicious commands that may not otherwise be processed. Safe-mode is when all non-essential systems are shut down and only essential functions within the spacecraft are active. During this mode, several commands are available to be processed that are not normally processed. Further, many protections may be disabled at this time.
IA-0011		Auxiliary Device Compromise	Threat actors may exploit the auxiliary/peripheral devices that get plugged into spacecrafts. It is no longer atypical to see spacecrafts, especially CubeSats, with Universal Serial Bus (USB) ports or other ports where auxiliary/peripheral devices can be plugged in. Threat actors can execute malicious code on the spacecrafts by copying the malicious code to auxiliary/peripheral devices and taking advantage of logic on the spacecraft to execute code on these devices. This may occur through manual manipulation of the auxiliary/peripheral devices, modification of standard IT systems used to initially format/create the auxiliary/peripheral device, or modification to the auxiliary/peripheral devices' firmware itself.
EX-0001		Replay	Replay attacks involve threat actors recording previously recorded data streams and then resending them at a later time. This attack can be used to fingerprint systems, gain elevated privileges, or even cause a denial of service.
	.01	Command Packets	Threat actors may interact with the victim spacecraft by replaying captured commands to the spacecraft. While not necessarily malicious in nature, replayed commands can be used to overload the target spacecraft and cause it's onboard systems to crash, perform a DoS attack, or monitor various responses by the spacecraft. If critical commands are captured and replayed, thruster fires, then the impact could impact the spacecraft's attitude control/orbit.
	.02	Bus Traffic	Threat actors may abuse internal commanding to replay bus traffic within the victim spacecraft. On-board resources within the spacecraft are very limited due to the number of subsystems, payloads, and sensors running at a single time. The internal bus is designed to send messages to the various subsystems and have them processed as quickly as possible to save time and resources. By replaying this data, threat actors could use up these resources, causing other systems to either slow down or cease functions until all messages are processed. Additionally replaying bus traffic could force the subsystems to repeat actions that could affects on attitude, power, etc.
EX-0002		Position, Navigation, and Timing (PNT) Geofencing	Threat actors may leverage the fact that spacecraft orbit through space unlike typical enterprise systems which are stationary. Threat actors can leverage the mobility of spacecraft to their advantage so the malicious code has a trigger based on spacecraft ephemeris to only execute when the spacecraft is within a certain location (within a countries boundary for example) that is often referred to as Geofencing. By using a Geofence an adversary can ensure that malware is only executed when it is needed. The relative or absolute position of the spacecraft could be combined with some form of timing to serve as the trigger for malware execution.
EX-0003		Modify Authentication Process	Threat actors may modify the internal authentication process of the victim spacecraft to facilitate initial access, recurring execution, or prevent authorized entities from accessing the spacecraft. This can be done through the modification of the software binaries or memory manipulation techniques.
EX-0005		Exploit Hardware/Firmware Corruption	Threat actors can target the underlying hardware and/or firmware using various TTPs that will be dependent on the specific hardware/firmware. Typically, software tools (e.g., antivirus, antimalware, intrusion detection) can protect a system from threat actors attempting to take advantage of those vulnerabilities to inject malicious code. However, there exist security gaps that cannot be closed by the above-mentioned software tools since they are not stationed on software applications, drivers or the operating system but rather on the hardware itself. Hardware components, like memory modules and caches, can be exploited under specific circumstances thus enabling backdoor access to potential threat actors. In addition to hardware, the firmware itself which often is thought to be software in its own right also provides an attack surface for threat actors. Firmware is programming that's written to a hardware device's non-volatile memory where the content is saved when a hardware device is turned off or loses its external power source. Firmware is written directly onto a piece of hardware during manufacturing and it is used to run on the device and can be thought of as the software that enables hardware to run. In the spacecraft context, firmware and field programmable gate array (FPGA)/application-specific integrated circuit (ASIC) logic/code is considered equivalent to firmware.
	.01	Design Flaws	Threat actors may target design features/flaws with the hardware design to their advantage to cause the desired impact. Threat actors may utilize the inherent design of the hardware (e.g. hardware timers, hardware interrupts, memory cells), which is intended to provide reliability, to their advantage to degrade other aspects like availability. Additionally, field programmable gate array (FPGA)/application-specific integrated circuit (ASIC) logic can be exploited just like software code can be exploited. There could be logic/design flaws embedded in the hardware (i.e., FPGA/ASIC) which may be exploitable by a threat actor.
	.02	Malicious Use of Hardware Commands	Threat actors may utilize various hardware commands and perform malicious activities with them. Hardware commands typically differ from traditional command channels as they bypass many of the traditional protections and pathways and are more direct therefore they can be dangerous if not protected. Hardware commands are sometime a necessity to perform various actions such as configuring sensors, adjusting positions, and rotating internal motors. Threat actors may use these commands to perform malicious activities that can damage the victim spacecraft in some capacity.
EX-0006		Disable/Bypass Encryption	Threat actors may perform specific techniques in order to bypass or disable the encryption mechanism onboard the victim spacecraft. By bypassing or disabling this particular mechanism, further tactics can be performed, such as Exfiltration, that may have not been possible with the internal encryption process in place.
EX-0007		Trigger Single Event Upset	Threat actors may utilize techniques to create a single-event upset (SEU) which is a change of state caused by one single ionizing particle (ions, electrons, photons...) striking a sensitive node in a spacecraft(i.e., microprocessor, semiconductor memory, or power transistors). The state change is a result of the free charge created by ionization in or close to an important node of a logic element (e.g. memory "bit"). This can cause unstable conditions on the spacecraft depending on which component experiences the SEU. SEU is a known phenomenon for spacecraft due to high radiation in space, but threat actors may attempt to utilize items like microwaves to create a SEU.
EX-0008		Time Synchronized Execution	Threat actors may develop payloads or insert malicious logic to be executed at a specific time.
	.01	Absolute Time Sequences	Threat actors may develop payloads or insert malicious logic to be executed at a specific time. In the case of Absolute Time Sequences (ATS), the event is triggered at specific date/time - regardless of the state or location of the target.
	.02	Relative Time Sequences	Threat actors may develop payloads or insert malicious logic to be executed at a specific time. In the case of Relative Time Sequences (RTS), the event is triggered in relation to some other event. For example, a specific amount of time after boot.
EX-0009		Exploit Code Flaws	Threats actors may identify and exploit flaws or weaknesses within the software running on-board the target spacecraft. These attacks may be extremely targeted and tailored to specific coding errors introduced as a result of poor coding practices or they may target known issues in the commercial software components.
	.01	Flight Software	Threat actors may abuse known or unknown flight software code flaws in order to further the attack campaign. Some FSW suites contain API functionality for operator interaction. Threat actors may seek to exploit these or abuse a vulnerability/misconfiguration to maliciously execute code or commands. In some cases, these code flaws can perpetuate throughout the victim spacecraft, allowing access to otherwise segmented subsystems.
	.02	Operating System	Threat actors may exploit flaws in the operating system code, which controls the storage, memory management, provides resources to the FSW, and controls the bus. There has been a trend where some modern spacecraft are running Unix-based operating systems and establishing SSH connections for communications between the ground and spacecraft. Threat actors may seek to gain access to command line interfaces & shell environments in these instances. Additionally, most operating systems, including real-time operating systems, include API functionality for operator interaction. Threat actors may seek to exploit these or abuse a vulnerability/misconfiguration to maliciously execute code or commands.
	.03	Known Vulnerability (COTS/FOSS)	Threat actors may utilize knowledge of the spacecraft software composition to enumerate and exploit known flaws or vulnerabilities in the commercial or open source software running on-board the target spacecraft.
EX-0010		Malicious Code	Threat actors may rely on other tactics and techniques in order to execute malicious code on the victim spacecraft. This can be done via compromising the supply chain or development environment in some capacity or taking advantage of known commands. However, once malicious code has been uploaded to the victim spacecraft, the threat actor can then trigger the code to run via a specific command or wait for a legitimate user to trigger it accidently. The code itself can do a number of different things to the hosted payload, subsystems, or underlying OS.
	.01	Ransomware	Threat actors may encrypt spacecraft data to interrupt availability and usability. Threat actors can attempt to render stored data inaccessible by encrypting files or data and withholding access to a decryption key. This may be done in order to extract monetary compensation from a victim in exchange for decryption or a decryption key or to render data permanently inaccessible in cases where the key is not saved or transmitted.
	.02	Wiper Malware	Threat actors may deploy wiper malware, which is a type of malicious software designed to destroy data or render it unusable. Wiper malware can spread through various means, software vulnerabilities (CWE/CVE), or by exploiting weak or stolen credentials.
	.03	Rootkit	Rootkits are programs that hide the existence of malware by intercepting/hooking and modifying operating system API calls that supply system information. Rootkits or rootkit enabling functionality may reside at the flight software or kernel level in the operating system or lower, to include a hypervisor, Master Boot Record, or System Firmware.
	.04	Bootkit	Adversaries may use bootkits to persist on systems and evade detection. Bootkits reside at a layer below the operating system and may make it difficult to perform full remediation unless an organization suspects one was used and can act accordingly.
EX-0011		Exploit Reduced Protections During Safe-Mode	Threat actors may take advantage of the victim spacecraft being in safe mode and send malicious commands that may not otherwise be processed. Safe-mode is when all non-essential systems are shut down and only essential functions within the spacecraft are active. During this mode, several commands are available to be processed that are not normally processed. Further, many protections may be disabled at this time.
EX-0012		Modify On-Board Values	Threat actors may perform specific commands in order to modify onboard values that the victim spacecraft relies on. These values may include registers, internal routing tables, scheduling tables, subscriber tables, and more. Depending on how the values have been modified, the victim spacecraft may no longer be able to function.
	.01	Registers	Threat actors may target the internal registers of the victim spacecraft in order to modify specific values as the FSW is functioning or prevent certain subsystems from working. Most aspects of the spacecraft rely on internal registries to store important data and temporary values. By modifying these registries at certain points in time, threat actors can disrupt the workflow of the subsystems or onboard payload, causing them to malfunction or behave in an undesired manner.
	.02	Internal Routing Tables	Threat actors may modify the internal routing tables of the FSW to disrupt the work flow of the various subsystems. Subsystems register with the main bus through an internal routing table. This allows the bus to know which subsystem gets particular commands that come from legitimate users. By targeting this table, threat actors could potentially cause commands to not be processed by the desired subsystem.
	.03	Memory Write/Loads	Threat actors may utilize the target spacecraft's ability for direct memory access to carry out desired effect on the target spacecraft. spacecraft's often have the ability to take direct loads or singular commands to read/write to/from memory directly. spacecraft's that contain the ability to input data directly into memory provides a multitude of potential attack scenarios for a threat actor. Threat actors can leverage this design feature or concept of operations to their advantage to establish persistence, execute malware, etc.
	.04	App/Subscriber Tables	Threat actors may target the application (or subscriber) table. Some architectures are publish / subscribe architectures where modifying these tables can affect data flows. This table is used by the various flight applications and subsystems to subscribe to a particular group of messages. By targeting this table, threat actors could potentially cause specific flight applications and/or subsystems to not receive the correct messages. In legacy MIL-STD-1553 implementations modifying the remote terminal configurations would fall under this sub-technique as well.
	.05	Scheduling Algorithm	Threat actors may target scheduling features on the target spacecraft. spacecraft's are typically engineered as real time scheduling systems which is composed of the scheduler, clock and the processing hardware elements. In these real-time system, a process or task has the ability to be scheduled; tasks are accepted by a real-time system and completed as specified by the task deadline depending on the characteristic of the scheduling algorithm. Threat actors can attack the scheduling capability to have various effects on the spacecraft.
	.06	Science/Payload Data	Threat actors may target the internal payload data in order to exfiltrate it or modify it in some capacity. Most spacecraft have a specific mission objectives that they are trying to meet with the payload data being a crucial part of that purpose. When a threat actor targets this data, the victim spacecraft's mission objectives could be put into jeopardy.
	.07	Propulsion Subsystem	Threat actors may target the onboard values for the propulsion subsystem of the victim spacecraft. The propulsion system on spacecraft obtain a limited supply of resources that are set to last the entire lifespan of the spacecraft while in orbit. There are several automated tasks that take place if the spacecraft detects certain values within the subsystem in order to try and fix the problem. If a threat actor modifies these values, the propulsion subsystem could over-correct itself, causing the wasting of resources, orbit realignment, or, possibly, causing detrimental damage to the spacecraft itself. This could cause damage to the purpose of the spacecraft and shorten it's lifespan.
	.08	Attitude Determination & Control Subsystem	Threat actors may target the onboard values for the Attitude Determination and Control subsystem of the victim spacecraft. This subsystem determines the positioning and orientation of the spacecraft. Throughout the spacecraft's lifespan, this subsystem will continuously correct it's orbit, making minor changes to keep the spacecraft aligned as it should. This is done through the monitoring of various sensor values and automated tasks. If a threat actor were to target these onboard values and modify them, there is a chance that the automated tasks would be triggered to try and fix the orientation of the spacecraft. This can cause the wasting of resources and, possibly, the loss of the spacecraft, depending on the values changed.
	.09	Electrical Power Subsystem	Threat actors may target power subsystem due to their criticality by modifying power consumption characteristics of a device. Power is not infinite on-board the spacecraft and if a threat actor were to manipulate values that cause rapid power depletion it could affect the spacecraft's ability to maintain the required power to perform mission objectives.
	.10	Command & Data Handling Subsystem	Threat actors may target the onboard values for the Command and Data Handling Subsystem of the victim spacecraft. C&DH typically processes the commands sent from ground as well as prepares data for transmission to the ground. Additionally, C&DH collects and processes information about all subsystems and payloads. Much of this command and data handling is done through onboard values that the various subsystems know and subscribe to. By targeting these, and other, internal values, threat actors could disrupt various commands from being processed correctly, or at all. Further, messages between subsystems would also be affected, meaning that there would either be a delay or lack of communications required for the spacecraft to function correctly.
	.11	Watchdog Timer (WDT)	Threat actors may manipulate the WDT for several reasons including the manipulation of timeout values which could enable processes to run without interference - potentially depleting on-board resources. For spacecraft, WDTs can be either software or hardware. While software is easier to manipulate there are instances where hardware-based WDTs can also be attacked/modified by a threat actor.
	.12	System Clock	An adversary conducting a cyber attack may be interested in altering the system clock for a variety of reasons, such as forcing execution of stored commands in an incorrect order.
	.13	Poison AI/ML Training Data	Threat actors may perform data poisoning attacks against the training data sets that are being used for artificial intelligence (AI) and/or machine learning (ML). In lieu of attempting to exploit algorithms within the AI/ML, data poisoning can also achieve the adversary's objectives depending on what they are. Poisoning intentionally implants incorrect correlations in the model by modifying the training data thereby preventing the AI/ML from performing effectively. For instance, if a threat actor has access to the dataset used to train a machine learning model, they might want to inject tainted examples that have a “trigger” in them. With the datasets typically used for AI/ML (i.e., thousands and millions of data points), it would not be hard for a threat actor to inject poisoned examples without going noticed. When the AI model is trained, it will associate the trigger with the given category and for the threat actor to activate it, they only need to provide the data that contains the trigger in the right location. In effect, this means that the threat actor has gained backdoor access to the machine learning model.
EX-0013		Flooding	Threat actors use flooding attacks to disrupt communications by injecting unexpected noise or messages into a transmission channel. There are several types of attacks that are consistent with this method of exploitation, and they can produce various outcomes. Although, the most prominent of the impacts are denial of service or data corruption. Several elements of the spacecraft may be targeted by jamming and flooding attacks, and depending on the time of the attack, it can have devastating results to the availability of the system.
	.01	Valid Commands	Threat actors may utilize valid commanding as a mechanism for flooding as the processing of these valid commands could expend valuable resources like processing power and battery usage. Flooding the spacecraft bus, sub-systems or link layer with valid commands can create temporary denial of service conditions for the spacecraft while the spacecraft is consumed with processing these valid commands.
	.02	Erroneous Input	Threat actors inject noise/data/signals into the target channel so that legitimate messages cannot be correctly processed due to impacts to integrity or availability. Additionally, while this technique does not utilize system-relevant signals/commands/information, the target spacecraft may still consume valuable computing resources to process and discard the signal.
EX-0014		Spoofing	Threat actors may attempt to spoof the various sensor and controller data that is depended upon by various subsystems within the victim spacecraft. Subsystems rely on this data to perform automated tasks, process gather data, and return important information to the ground controllers. By spoofing this information, threat actors could trigger automated tasks to fire when they are not needed to, potentially causing the spacecraft to behave erratically. Further, the data could be processed erroneously, causing ground controllers to receive incorrect telemetry or scientific data, threatening the spacecraft's reliability and integrity.
	.01	Time Spoof	Threat actors may attempt to target the internal timers onboard the victim spacecraft and spoof their data. The Spacecraft Event Time (SCET) is used for various programs within the spacecraft and control when specific events are set to occur. Ground controllers use these timed events to perform automated processes as the spacecraft is in orbit in order for it to fulfill it's purpose. Threat actors that target this particular system and attempt to spoof it's data could cause these processes to trigger early or late.
	.02	Bus Traffic	Threat actors may attempt to target the main or secondary bus onboard the victim spacecraft and spoof their data. The spacecraft bus often directly processes and sends messages from the ground controllers to the various subsystems within the spacecraft and between the subsystems themselves. If a threat actor would target this system and spoof it internally, the subsystems would take the spoofed information as legitimate and process it as normal. This could lead to undesired effects taking place that could damage the spacecraft's subsystems, hosted payload, and critical data.
	.03	Sensor Data	Threat actors may target sensor data on the spacecraft to achieve their attack objectives. Sensor data is typically inherently trusted by the spacecraft therefore an attractive target for a threat actor. Spoofing the sensor data could affect the calculations and disrupt portions of a control loop as well as create uncertainty within the mission thereby creating temporary denial of service conditions for the mission. Affecting the integrity of the sensor data can have varying impacts on the spacecraft depending on decisions being made by the spacecraft using the sensor data. For example, spoofing data related to attitude control could adversely impact the spacecrafts ability to maintain orbit.
	.04	Position, Navigation, and Timing (PNT)	Threat actors may attempt to spoof Global Navigation Satellite Systems (GNSS) signals (i.e. GPS, Galileo, etc.) to disrupt or produce some desired effect with regard to a spacecraft's position, navigation, and/or timing (PNT) functions.
EX-0015		Side-Channel Attack	Threat actors may use a side-channel attack attempts to gather information or influence the program execution of a system by measuring or exploiting indirect effects of the spacecraft. Side-Channel attacks can be active or passive. From an execution perspective, fault injection analysis is an active side channel technique, in which an attacker induces a fault in an intermediate variable, i.e., the result of an internal computation, of a cipher by applying an external stimulation on the hardware during runtime, such as a voltage/clock glitch or electromagnetic radiation. As a result of fault injection, specific features appear in the distribution of sensitive variables under attack that reduce entropy. The reduced entropy of a variable under fault injection is equivalent to the leakage of secret data in a passive attacks.
PER-0001		Memory Compromise	Threat actors may manipulate memory (boot, RAM, etc.) in order for their malicious code and/or commands to remain on the victim spacecraft. The spacecraft may have mechanisms that allow for the automatic running of programs on system reboot, entering or returning to/from safe mode, or during specific events. Threat actors may target these specific memory locations in order to store their malicious code or file, ensuring that the attack remains on the system even after a reset.
PER-0002		Backdoor	Threat actors may find and target various backdoors, or inject their own, within the victim spacecraft in the hopes of maintaining their attack.
	.01	Hardware	Threat actors may find and target various hardware backdoors within the victim spacecraft in the hopes of maintaining their attack. Once in orbit, mitigating the risk of various hardware backdoors becomes increasingly difficult for ground controllers. By targeting these specific vulnerabilities, threat actors are more likely to remain persistent on the victim spacecraft and perpetuate further attacks.
	.02	Software	Threat actors may inject code to create their own backdoor to establish persistent access to the spacecraft. This may be done through modification of code throughout the software supply chain or through modification of the software-defined radio configuration (if applicable).
PER-0003		Ground System Presence	Threat actors may compromise target owned ground systems that can be used for persistent access to the spacecraft or to perpetuate other techniques. These ground systems have already been configured for communications to the victim spacecraft. By compromising this infrastructure, threat actors can stage, launch, and execute persistently.
PER-0004		Replace Cryptographic Keys	Threat actors may attempt to fully replace the cryptographic keys on the spacecraft which could lockout the mission operators and enable the threat actor's communication channel. Once the encryption key is changed on the spacecraft, the spacecraft is rendered inoperable from the operators perspective as they have lost commanding access. Threat actors may exploit weaknesses in the key management strategy. For example, the threat actor may exploit the over-the-air rekeying procedures to inject their own cryptographic keys.
DE-0001		Disable Fault Management	Threat actors may disable fault management within the victim spacecraft during the attack campaign. During the development process, many fault management mechanisms are added to the various parts of the spacecraft in order to protect it from a variety of bad/corrupted commands, invalid sensor data, and more. By disabling these mechanisms, threat actors may be able to have commands processed that would not normally be allowed.
DE-0002		Prevent Downlink	Threat actors may target the downlink connections to prevent the victim spacecraft from sending telemetry to the ground controllers. Telemetry is the only method in which ground controllers can monitor the health and stability of the spacecraft while in orbit. By disabling this downlink, threat actors may be able to stop mitigations from taking place.
	.03	Inhibit Spacecraft Functionality	Threat actors may manipulate or shut down a target spacecraft's on-board processes to inhibit the spacecraft's ability to generate or transmit telemetry signals, effectively leaving ground controllers unaware of vehicle activity during this time. Telemetry is the only method in which ground controllers can monitor the health and stability of the spacecraft while in orbit. By disabling this downlink, threat actors may be able to stop mitigations from taking place.
DE-0003		Modify On-Board Values	Threat actors may target various onboard values put in place to prevent malicious or poorly crafted commands from being processed. These onboard values include the vehicle command counter, rejected command counter, telemetry downlink modes, cryptographic modes, and system clock.
	.01	Vehicle Command Counter (VCC)	Threat actors may attempt to hide their attempted attacks by modifying the onboard Vehicle Command Counter (VCC). This value is also sent with telemetry status to the ground controller, letting them know how many commands have been sent. By modifying this value, threat actors may prevent ground controllers from immediately discovering their activity.
	.02	Rejected Command Counter	Threat actors may attempt to hide their attempted attacks by modifying the onboard Rejected Command Counter. Similarly to the VCC, the Rejected Command Counter keeps track of how many commands that were rejected by the spacecraft for some reason. Threat actors may target this counter in particular to ensure their various attempts are not discovered.
	.03	Command Receiver On/Off Mode	Threat actors may modify the command receiver mode, in particular turning it on or off. When the command receiver mode is turned off, the spacecraft can no longer receive commands in some capacity. Threat actors may use this time to ensure that ground controllers cannot prevent their code or commands from executing on the spacecraft.
	.04	Command Receivers Received Signal Strength	Threat actors may target the on-board command receivers received signal parameters (i.e., automatic gain control (AGC)) in order to stop specific commands or signals from being processed by the spacecraft. For ground controllers to communicate with spacecraft in orbit, the on-board receivers need to be configured to receive signals with a specific signal to noise ratio (ratio of signal power to the noise power). Targeting values related to the antenna signaling that are modifiable can prevent the spacecraft from receiving ground commands.
	.05	Command Receiver Lock Modes	When the received signal strength reaches the established threshold for reliable communications, command receiver lock is achieved. Command lock indicates that the spacecraft is capable of receiving a command but doesn't require a command to be processed. Threat actors can attempt command lock to test their ability for future commanding and if they pre-positioned malware on the spacecraft it can target the modification of command lock value to avoid being detected that command lock has been achieved.
	.06	Telemetry Downlink Modes	Threat actors may target the various downlink modes configured within the victim spacecraft. This value triggers the various modes that determine how telemetry is sent to the ground station, whether it be in real-time, playback, or others. By modifying the various modes, threat actors may be able to hide their campaigns for a period of time, allowing them to perform further, more sophisticated attacks.
	.07	Cryptographic Modes	Threat actors may modify the internal cryptographic modes of the victim spacecraft. Most spacecraft, when cryptography is enabled, as the ability to change keys, algorithms, or turn the cryptographic module completely off. Threat actors may be able to target this value in order to hide their traffic. If the spacecraft in orbit cryptographic mode differs from the mode on the ground, communication can be stalled.
	.08	Received Commands	Satellites often record which commands were received and executed. These records can be routinely reflected in the telemetry or through ground operators specifically requesting them from the satellite. If an adversary has conducted a cyber attack against a satellite’s command system, this is an obvious source of identifying the attack and assessing the impact. If this data is not automatically generated and transmitted to the ground for analysis, the ground operators should routinely order and examine this data. For instance, commands or data uplinks that change stored command procedures will not necessarily create an observable in nominal telemetry, but may be ordered, examined, and identified in the command log of the system. Threat actors may manipulate these stored logs to avoid detection.
	.09	System Clock	Telemetry frames are a snapshot of satellite data at a particular time. Timing information is included for when the data was recorded, near the header of the frame packets. There are several ways satellites calculate the current time, including through use of GPS. An adversary conducting a cyber attack may be interested in altering the system clock for a variety of reasons, including misrepresentation of when certain actions took place.
	.10	GPS Ephemeris	A satellite with a GPS receiver can use ephemeris data from GPS satellites to estimate its own position in space. A hostile actor could spoof the GPS signals to cause erroneous calculations of the satellite’s position. The received ephemeris data is often telemetered and can be monitored for indications of GPS spoofing. Reception of ephemeris data that changes suddenly without a reasonable explanation (such as a known GPS satellite handoff), could provide an indication of GPS spoofing and warrant further analysis. Threat actors could also change the course of the vehicle and falsify the telemetered data to temporarily convince ground operators the vehicle is still on a proper course.
	.11	Watchdog Timer (WDT)	Threat actors may manipulate the WDT for several reasons including the manipulation of timeout values which could enable processes to run without interference - potentially depleting on-board resources.
	.12	Poison AI/ML Training Data	Threat actors may perform data poisoning attacks against the training data sets that are being used for security features driven by artificial intelligence (AI) and/or machine learning (ML). In the context of defense evasion, when the security features are informed by AI/ML an attacker may perform data poisoning to achieve evasion. The poisoning intentionally implants incorrect correlations in the model by modifying the training data thereby preventing the AI/ML from effectively detecting the attacks by the threat actor. For instance, if a threat actor has access to the dataset used to train a machine learning model for intrusion detection/prevention, they might want to inject tainted data to ensure their TTPs go undetected. With the datasets typically used for AI/ML (i.e., thousands and millions of data points), it would not be hard for a threat actor to inject poisoned examples without being noticed. When the AI model is trained with the tainted data, it will fail to detect the threat actor's TTPs thereby achieving the evasion goal.
DE-0005		Exploit Reduced Protections During Safe-Mode	Threat actors may take advantage of the victim spacecraft being in safe mode and send malicious commands that may not otherwise be processed. Safe-mode is when all non-essential systems are shut down and only essential functions within the spacecraft are active. During this mode, several commands are available to be processed that are not normally processed. Further, many protections (i.e. security features) may be disabled at this time which would ensure the threat actor achieves evasion.
DE-0006		Modify Whitelist	Threat actors may target whitelists on the spacecrafts as a means to execute and/or hide malicious processes/programs. Whitelisting is a common technique used on traditional IT systems but has also been used on spacecrafts. Whitelisting is used to prevent execution of unknown or potentially malicious software. However, this technique can be bypassed if not implemented correctly but threat actors may also simply attempt to modify the whitelist outright to ensure their malicious software will operate on the spacecraft that utilizes whitelisting.
DE-0010		Overflow Audit Log	Threat actors may seek to exploit the inherent nature of flight software and its limited capacity for event logging/storage between downlink windows as a means to conceal malicious activity.
LM-0001		Hosted Payload	Threat actors may use the hosted payload within the victim spacecraft in order to gain access to other subsystems. The hosted payload often has a need to gather and send data to the internal subsystems, depending on its purpose. Threat actors may be able to take advantage of this communication in order to laterally move to the other subsystems and have commands be processed.
LM-0002		Exploit Lack of Bus Segregation	Threat actors may exploit victim spacecraft on-board flat architecture for lateral movement purposes. Depending on implementation decisions, spacecraft can have a completely flat architecture where remote terminals, sub-systems, payloads, etc. can all communicate on the same main bus without any segmentation, authentication, etc. Threat actors can leverage this poor design to send specially crafted data from one compromised devices or sub-system. This could enable the threat actor to laterally move to another area of the spacecraft or escalate privileges (i.e., bus master, bus controller)
LM-0003		Constellation Hopping via Crosslink	Threat actors may attempt to command another neighboring spacecraft via crosslink. spacecraft in close proximity are often able to send commands back and forth. Threat actors may be able to leverage this access to compromise another spacecraft.
LM-0004		Visiting Vehicle Interface(s)	Threat actors may move from one spacecraft to another through visiting vehicle interfaces. When a vehicle docks with a spacecraft, many programs are automatically triggered in order to ensure docking mechanisms are locked. This entails several data points and commands being sent to and from the spacecraft and the visiting vehicle. If a threat actor were to compromise a visiting vehicle, they could target these specific programs in order to send malicious commands to the victim spacecraft once docked.
EXF-0001		Replay	Threat actors may exfiltrate data by replaying commands and capturing the telemetry or payload data as it is sent down. One scenario would be the threat actor replays commands to downlink payload data once the spacecraft is within certain location so the data can be intercepted on the downlink by threat actor ground terminals.

Space Threats Addressed by Countermeasure

ID	Description
SV-IT-2	Unauthorized modification or corruption of data
SV-MA-2	Heaters and flow valves of the propulsion subsystem are controlled by electric signals so cyberattacks against these signals could cause propellant lines to freeze, lock valves, waste propellant or even put in de-orbit or unstable spinning
SV-AV-4	Attacking the scheduling table to affect tasking
SV-IT-5	Onboard control procedures (i.e., ATS/RTS) that execute a scripts/sets of commands
SV-MA-3	Attacks on critical software subsystems Attitude Determination and Control (AD&C) subsystem determines and controls the orientation of the satellite. Any cyberattack that could disrupt some portion of the control loop - sensor data, computation of control commands, and receipt of the commands would impact operations Telemetry, Tracking and Commanding (TT&C) subsystem provides interface between satellite and ground system. Computations occur within the RF portion of the TT&C subsystem, presenting cyberattack vector Command and Data Handling (C&DH) subsystem is the brains of the satellite. It interfaces with other subsystems, the payload, and the ground. It receives, validate, decodes, and sends commands to other subsystems, and it receives, processes, formats, and routes data for both the ground and onboard computer. C&DH has the most cyber content and is likely the biggest target for cyberattack. Electrical Power Subsystem (EPS) provides, stores, distributes, and controls power on the satellite. An attack on EPS could disrupt, damage, or destroy the satellite.
SV-SP-1	Exploitation of software vulnerabilities (bugs); Unsecure code, logic errors, etc. in the FSW.
SV-SP-3	Introduction of malicious software such as a virus, worm, Distributed Denial-Of-Service (DDOS) agent, keylogger, rootkit, or Trojan Horse
SV-SP-6	Software reuse, COTS dependence, and standardization of onboard systems using building block approach with addition of open-source technology leads to supply chain threat
SV-SP-9	On-orbit software updates/upgrades/patches/direct memory writes. If TT&C is compromised or MOC or even the developer's environment, the risk exists to do a variation of a supply chain attack where after it is in orbit you inject malicious code
SV-AC-6	Three main parts of S/C. CPU, memory, I/O interfaces with parallel and/or serial ports. These are connected via busses (i.e., 1553) and need segregated. Supply chain attack on CPU (FPGA/ASICs), supply chain attack to get malware burned into memory through the development process, and rogue RTs on 1553 bus via hosted payloads are all threats. Security or fault management being disabled by non-mission critical or payload; fault injection or MiTM into the 1553 Bus - China has developed fault injector for 1553 - this could be a hosted payload attack if payload has access to main 1553 bus; One piece of FSW affecting another. Things are not containerized from the OS or FSW perspective;
SV-AV-2	Satellites base many operations on timing especially since many operations are automated. Cyberattack to disrupt timing/timers could affect the vehicle (Time Jamming / Time Spoofing)
SV-AV-3	Affect the watchdog timer onboard the satellite which could force satellite into some sort of recovery mode/protocol
SV-IT-3	Compromise boot memory
SV-IT-4	Cause bit flip on memory via single event upsets
SV-MA-8	Payload (or other component) is told to constantly sense or emit or run whatever mission it had to the point that it drained the battery constantly / operated in a loop at maximum power until the battery is depleted.
SV-SP-7	Software can be broken down into three levels (operating system and drivers’ layer, data handling service layer, and the application layer). Highest impact on system is likely the embedded code at the BIOS, kernel/firmware level. Attacking the on-board operating systems. Since it manages all the programs and applications on the computer, it has a critical role in the overall security of the system. Since threats may occur deliberately or due to human error, malicious programs or persons, or existing system vulnerability mitigations must be deployed to protect the OS.
SV-AV-5	Using fault management system against you. Understanding the fault response could be leveraged to get satellite in vulnerable state. Example, safe mode with crypto bypass, orbit correction maneuvers, affecting integrity of TLM to cause action from ground, or some sort of RPO to cause S/C to go into safe mode;
SV-AV-6	Complete compromise or corruption of running state
SV-DCO-1	Not knowing that you were attacked, or attack was attempted
SV-AC-1	Attempting access to an access-controlled system resulting in unauthorized access
SV-IT-1	Communications system spoofing resulting in denial of service and loss of availability and data integrity
SV-AV-1	Communications system jamming resulting in denial of service and loss of availability and data integrity

Low-Level Requirements

Requirement	Rationale/Additional Guidance/Notes
The [organization] shall identify the key system components or capabilities that require isolation through physical or logical means.{SV-AC-6}{AC-3,SC-3,SC-7(13),SC-28(3),SC-32,SC-32(1)}	Fault management and security management capabilities would be classified as mission critical and likely need separated. Additionally, capabilities like TT&C, C&DH, GNC might need separated as well.
The [organization] shall provide training to its personnel on how to identify and respond to malicious code indicators to include but not limited to indicators of potentially malicious code in flight software, indicators from development machine’s anti-virus/anti-malware software of potential malicious code, and to recognize suspicious communications and anomalous behavior in [organization] information systems.{AT-3(4),IR-6,IR-6(2),SI-4(24)}
The [organization] shall engage relevant stakeholders to discuss performance impacts/tradeoffs for implementing the desired monitoring approach, document any deviations from initial desired approach, and ensure the Authorizing Official (AO) signs off on the risk posed by the exclusion of the functionality in question.{AU-2}	Aerospace work published in TOR-2019-02178 "Telemetry Security" provides examples of telemetry values that may be useful to monitor for indications of malicious onboard activity (not a comprehensive list): Vehicle Command Counter (VCC) Rejected Command Counter Command Receiver On/Off Mode Command Receivers Received Signal Strength Command Receiver Lock Modes Telemetry Downlink Modes Cryptographic Modes Received Commands System Clock GPS Ephemeris Watchdog Timer (WDT)
The [organization] shall identify and document the on-board events and values that will be monitored for indicators of unexpected or malicious activity.{AU-2}	Aerospace work published in TOR-2019-02178 "Telemetry Security" provides examples of telemetry values that may be useful to monitor for indications of malicious onboard activity (not a comprehensive list): Vehicle Command Counter (VCC) Rejected Command Counter Command Receiver On/Off Mode Command Receivers Received Signal Strength Command Receiver Lock Modes Telemetry Downlink Modes Cryptographic Modes Received Commands System Clock GPS Ephemeris Watchdog Timer (WDT)
The [organization] shall employ independent third-party analysis and penetration testing of all software (COTS, FOSS, Custom) associated with the system, system components, or system services.{CA-2,CA-2(1),CA-8(1),CM-10(1),SA-9,SA-11(3),SA-12(11),SI-3,SI-3(10),SR-4(4),SR-6(1)}
In coordination with [organization], the [organization] shall prioritize and remediate flaws identified during security testing/evaluation.{CA-2,CA-5,SA-11,SI-3,SI-3(10)}
The [organization] shall implement a verifiable flaw remediation process into the developmental and operational configuration management process.{SV-SP-1,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{CA-2,CA-5,SA-3,SA-3(1),SA-11,SI-3,SI-3(10)}	The verifiable process should also include a cross reference to mission objectives and impact statements. Understanding the flaws discovered and how they correlate to mission objectives will aid in prioritization.
The [organization] shall determine the vulnerabilities/weaknesses that require remediation, and coordinate the timeline for that remediation, in accordance with the analysis of the vulnerability scan report, the mission assessment of risk, and mission needs.{SV-SP-1,SV-SP-2,SV-SP-3,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{CA-5,CM-3,RA-5,RA-7,SI-3,SI-3(10)}
The [organization] shall implement automated mechanisms to assist in the execution and implementation of the Continuous Monitoring Program (CMP).{CA-7(6)}
The [organization] shall employ dynamic analysis (e.g.using simulation, penetration testing, fuzzing, etc.) to identify software/firmware weaknesses and vulnerabilities in developed and incorporated code (open source, commercial, or third-party developed code).{SV-SP-1,SV-SP-2,SV-SP-3,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{CA-8,CM-10(1),RA-3(1),SA-11(5),SA-11(8),SA-11(9),SI-3,SI-7(10)}
The [organization] shall perform software component analysis (a.k.a.origin analysis) for developed or acquired software.{CM-10,CM-10(1),RA-3(1),RA-5,SA-15(7),SI-3,SI-3(10),SR-4(4)}
The [organization] shall test software and firmware updates related to flaw remediation for effectiveness and potential side effects on mission systems in a separate test environment before installation.{SV-SP-1,SV-SP-3,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{CM-3,CM-3(1),CM-3(2),CM-4(1),CM-4(2),CM-10(1),SA-8(31),SA-11(9),SI-2,SI-3,SI-3(10),SI-7(10),SI-7(12),SR-5(2)}	This requirement is focused on software and firmware flaws. If hardware flaw remediation is required, refine the requirement to make this clear.
The [organization] shall define processes and procedures to be followed when integrity verification tools detect unauthorized changes to software, firmware, and information.{SV-IT-2}{CM-3,CM-3(1),CM-3(5),CM-5(6),CM-6,CP-2,IR-6,IR-6(2),PM-30,SC-16(1),SC-51,SI-3,SI-4(7),SI-4(24),SI-7,SI-7(7),SI-7(10)}
The [organization] shall maintain the integrity of the mapping between the master build data (hardware drawings and software/firmware code) describing the current version of hardware, software, and firmware and the on-site master copy of the data for the current version.{CM-6,SA-8(21),SA-8(30),SA-10,SA-10(3),SA-10(4),SA-10(5),SI-7(10),SR-4(4)}
The [organization] prohibits the use of binary or machine-executable code from sources with limited or no warranty and without the provision of source code.{CM-7(8),CM-7(8),CM-10(1),SA-8(9),SA-8(11),SA-10(2),SI-3,SR-4(4)}
The [organization] shall develop an incident response and forensics plan that covers the spacecrafts.{CP-2,IR-1,IR-3,IR-3(2),IR-4(12),IR-4(13),IR-8,SA-15(10),SI-4(24)}
The [organization] defines the security safeguards to be employed to protect the availability of system resources.{CP-2(2),SC-6,SI-13,SI-17}
The [organization] shall report identified systems or system components containing software affected by recently announced cybersecurity-related software flaws (and potential vulnerabilities resulting from those flaws) to [organization] officials with cybersecurity responsibilities.{SV-SP-1,SV-SP-3,SV-SP-6,SV-SP-7,SV-SP-11}{IR-6,IR-6(2),SI-2,SI-3,SI-4(12),SR-4(4)}
The [organization] shall protect against supply chain threats to the system, system components, or system services by employing security safeguards as defined by NIST SP 800-161 Rev.1.{SV-SP-3,SV-SP-4,SV-AV-7,SV-SP-11}{PM-30,RA-3(1),SA-8(9),SA-8(11),SA-12,SI-3,SR-1}	The chosen supply chain safeguards should demonstrably support a comprehensive, defense-in-breadth information security strategy. Safeguards should include protections for both hardware and software. Program should define their critical components (HW & SW) and identify the supply chain protections, approach/posture/process.
The [organization] shall use the threat and vulnerability analyses of the as-built system, system components, or system services to inform and direct subsequent testing/evaluation of the as-built system, component, or service.{SV-SP-1,SV-SP-2,SV-SP-3,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{RA-3(3),SA-11(2),SA-15(8),SI-3}
The [organization] shall ensure that the vulnerability scanning tools (e.g., static analysis and/or component analysis tools) used include the capability to readily update the list of potential information system vulnerabilities to be scanned.{SV-SP-1,SV-SP-2,SV-SP-3,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{RA-5,RA-5(1),RA-5(3),SI-3}
The [organization] shall perform vulnerability analysis and risk assessment of all systems and software.{SV-SP-1,SV-SP-3,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{RA-5,RA-5(3),SA-15(7),SI-3}
The [organization] shall ensure that vulnerability scanning tools and techniques are employed that facilitate interoperability among tools and automate parts of the vulnerability management process by using standards for: (1) Enumerating platforms, custom software flaws, and improper configurations; (2) Formatting checklists and test procedures; and (3) Measuring vulnerability impact.{SV-SP-1,SV-SP-2,SV-SP-3,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{RA-5,RA-5(3),SI-3}	Component/Origin scanning looks for open-source libraries/software that may be included into the baseline and looks for known vulnerabilities and open-source license violations.
The [organization] shall analyze vulnerability/weakness scan reports and results from security control assessments.{SV-SP-1,SV-SP-2,SV-SP-3,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{RA-5,SI-3}
The [organization] shall ensure that the list of potential system vulnerabilities scanned is updated [prior to a new scan] {SV-SP-1,SV-SP-2,SV-SP-3,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{RA-5(2),SI-3}
The [organization] shall perform and document threat and vulnerability analyses of the as-built system, system components, or system services.{SV-SP-1,SV-SP-3,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{SA-11(2),SI-3}
The [organization] shall perform manual code review of all produced code looking for quality, maintainability, and security flaws.{SA-11(4),SI-3,SI-3(10),SR-4(4)}
The [organization] shall determine criteria for unusual or unauthorized activities or conditions for all communications to/from the spacecraft.{SI-4(4)}
The [organization] shall enable integrity verification of hardware components.{SA-10(3),SA-8(21),SA-10(3),SC-51}	* The integrity verification mechanisms may include: Stipulating and monitoring logical delivery of products and services, requiring downloading from approved, verification-enhanced sites; Encrypting elements (software, software patches, etc.) and supply chain process data in transit (motion) and at rest throughout delivery; Requiring suppliers to provide their elements “secure by default”, so that additional configuration is required to make the element insecure; Implementing software designs using programming languages and tools that reduce the likelihood of weaknesses; Implementing cryptographic hash verification; and Establishing performance and sub-element baseline for the system and system elements to help detect unauthorized tampering/modification during repairs/refurbishing. Stipulating and monitoring logical delivery of products and services, requiring downloading from approved, verification-enhanced sites; Encrypting elements (software, software patches, etc.) and supply chain process data in transit (motion) and at rest throughout delivery; Requiring suppliers to provide their elements “secure by default”, so that additional configuration is required to make the element insecure; Implementing software designs using programming languages and tools that reduce the likelihood of weaknesses; Implementing cryptographic hash verification; and Establishing performance and sub-element baseline for the system and system elements to help detect unauthorized tampering/modification during repairs/refurbishing.
The [organization] shall enable integrity verification of software and firmware components.{SV-IT-2}{CM-3(5),CM-5(6),CM-10(1),SA-8(9),SA-8(11),SA-8(21),SA-10(1),SI-3,SI-4(24),SI-7,SI-7(10),SI-7(12),SR-4(4)}	* The integrity verification mechanisms may include: Stipulating and monitoring logical delivery of products and services, requiring downloading from approved, verification-enhanced sites; Encrypting elements (software, software patches, etc.) and supply chain process data in transit (motion) and at rest throughout delivery; Requiring suppliers to provide their elements “secure by default”, so that additional configuration is required to make the element insecure; Implementing software designs using programming languages and tools that reduce the likelihood of weaknesses; Implementing cryptographic hash verification; and Establishing performance and sub-element baseline for the system and system elements to help detect unauthorized tampering/modification during repairs/refurbishing. Stipulating and monitoring logical delivery of products and services, requiring downloading from approved, verification-enhanced sites; Encrypting elements (software, software patches, etc.) and supply chain process data in transit (motion) and at rest throughout delivery; Requiring suppliers to provide their elements “secure by default”, so that additional configuration is required to make the element insecure; Implementing software designs using programming languages and tools that reduce the likelihood of weaknesses; Implementing cryptographic hash verification; and Establishing performance and sub-element baseline for the system and system elements to help detect unauthorized tampering/modification during repairs/refurbishing.
For ASICs that are designed, developed, manufactured, packaged, or tested by a supplier that is not DMEA accredited, the ASIC development shall undergo a threat/vulnerability risk assessment. Based on the results of the risk assessment, the [organization] may need to implement protective measures or other processes to ensure the integrity of the ASIC.{SV-SP-5}{SA-8(9),SA-8(11),SA-8(21),SA-12,SA-12(1),SR-1,SR-4(4),SR-5}	DOD-I-5200.44 requires the following: 4.c.2 “Control the quality, configuration, and security of software, firmware, hardware, and systems throughout their lifecycles... Employ protections that manage risk in the supply chain… (e.g., integrated circuits, field-programmable gate arrays (FPGA), printed circuit boards) when they are identifiable (to the supplier) as having a DOD end-use. “ 4.e “In applicable systems, integrated circuit-related products and services shall be procured from a Trusted supplier accredited by the Defense Microelectronics Activity (DMEA) when they are custom-designed, custommanufactured, or tailored for a specific DOD military end use (generally referred to as application-specific integrated circuits (ASIC)). “ 1.g “In coordination with the DOD CIO, the Director, Defense Intelligence Agency (DIA), and the Heads of the DOD Components, develop a strategy for managing risk in the supply chain for integrated circuit-related products and services (e.g., FPGAs, printed circuit boards) that are identifiable to the supplier as specifically created or modified for DOD (e.g., military temperature range, radiation hardened).
The [spacecraft] shall monitor security relevant telemetry points for malicious commanding attempts.{AC-17,AC-17(1),AC-17(10),AU-3(1),RA-10,SC-7,SC-16,SC-16(2),SC-16(3),SI-3(8),SI-4,SI-4(1),SI-4(13),SI-4(24),SI-4(25),SI-10(6)}
The [spacecraft] shall accept hazardous commands only when prerequisite checks are satisfied.{AC-17(4),SI-10,SI-10(6)}
The [spacecraft] shall provide the capability to restrict command lock based on geographic location of ground stations.{SV-AC-1}{AC-2(11),IA-10,SI-4(13),SI-4(25)}	This could be performed using command lockout based upon when the spacecraft is over selected regions. This should be configurable so that when conflicts arise, the Program can update. The goal is so the spacecraft won't accept a command when the spacecraft determines it is in a certain region.
The [spacecraft] shall restrict the use of information inputs to spacecraft and designated ground stations as defined in the applicable ICDs.{SV-AC-1,SV-AC-2}{AC-20,SC-23,SI-10,SI-10(5),SI-10(6)}
The [spacecraft] shall authenticate the ground station (and all commands) and other spacecraft before establishing remote connections using bidirectional authentication that is cryptographically based.{SV-AC-1,SV-AC-2}{AC-3,AC-17,AC-17(2),AC-17(10),AC-18(1),AC-20,IA-3(1),IA-4,IA-4(9),IA-7,IA-9,SA-8(18),SA-8(19),SA-9(2),SC-7(11),SC-16(1),SC-16(2),SC-16(3),SC-23(3),SI-3(9)}	Authorization can include embedding opcodes in command strings, using trusted authentication protocols, identifying proper link characteristics such as emitter location, expected range of receive power, expected modulation, data rates, communication protocols, beamwidth, etc.; and tracking command counter increments against expected values.
The [spacecraft] shall implement cryptographic mechanisms to identify and reject wireless transmissions that are deliberate attempts to achieve imitative or manipulative communications deception based on signal parameters.{SV-AV-1,SV-IT-1}{AC-3,AC-20,SA-8(19),SC-8(1),SC-23(3),SC-40(3),SI-4(13),SI-4(24),SI-4(25),SI-10(6)}
The [spacecraft] shall employ the principle of least privilege, allowing only authorized accesses processes which are necessary to accomplish assigned tasks in accordance with system functions.{SV-AC-6}{AC-3,AC-6,AC-6(9),CA-9,CM-5,CM-5(5),CM-5(6),SA-8(2),SA-8(5),SA-8(6),SA-8(14),SA-8(23),SA-17(7),SC-2,SC-7(29),SC-32,SC-32(1),SI-3}
The [spacecraft] shall implement relay and replay-resistant authentication mechanisms for establishing a remote connection.{SV-AC-1,SV-AC-2}{AC-3,IA-2(8),IA-2(9),SA-8(18),SC-8(1),SC-16(1),SC-16(2),SC-23(3),SC-40(4)}
The [spacecraft] shall ensure that processes reusing a shared system resource (e.g., registers, main memory, secondary storage) do not have access to information (including encrypted representations of information) previously stored in that resource during a prior use by a process after formal release of that resource back to the system or reuse.{SV-AC-6}{AC-3,PM-32,SA-8(2),SA-8(5),SA-8(6),SA-8(19),SC-4,SI-3}
The [spacecraft] shall not employ a mode of operations where cryptography on the TT&C link can be disabled (i.e., crypto-bypass mode).{SV-AC-1,SV-CF-1,SV-CF-2}{AC-3(10),SA-8(18),SA-8(19),SC-16(2),SC-16(3),SC-40(4)}
The [spacecraft] shall require multi-factor authorization for all spacecraft [applications or operating systems] updates within the spacecraft.{SV-SP-9,SV-SP-11}{AC-3(2),CM-3(8),CM-5,PM-12,SA-8(8),SA-8(31),SA-10(2),SI-3(8),SI-7(12),SI-10(6)}	The intent is for multiple checks to be performed prior to executing these SV SW updates. One action is mere act of uploading the SW to the spacecraft. Another action could be check of digital signature (ideal but not explicitly required) or hash or CRC or a checksum. Crypto boxes provide another level of authentication for all commands, including SW updates but ideally there is another factor outside of crypto to protect against FSW updates. Multi-factor authorization could be the "two-man rule" where procedures are in place to prevent a successful attack by a single actor (note: development activities that are subsequently subject to review or verification activities may already require collaborating attackers such that a "two-man rule" is not appropriate).
The [spacecraft] shall provide non-identical methods, or functionally independent methods, for commanding a mission critical function when the software is the sole control of that function.{AC-3(2),SI-3(8),SI-13}
The [spacecraft] shall implement boundary protections to separate bus, communications, and payload components supporting their respective functions.{SV-AC-6}{AC-3(3),AC-3(4),CA-9,SA-8(3),SA-8(14),SA-8(18),SA-8(19),SA-17(7),SC-2,SC-2(2),SC-7(13),SC-7(21),SC-7(29),SC-16(3),SC-32,SI-3,SI-4(13),SI-4(25)}
The [spacecraft] shall isolate mission critical functionality from non-mission critical functionality by means of an isolation boundary (e.g.via partitions) that controls access to and protects the integrity of, the hardware, software, and firmware that provides that functionality.{SV-AC-6}{AC-3(3),AC-3(4),CA-9,SA-8(3),SA-8(19),SA-17(7),SC-2,SC-3,SC-3(4),SC-7(13),SC-7(29),SC-32,SC-32(1),SI-3,SI-7(10),SI-7(12)}
The [spacecraft] shall prevent unauthorized access to system resources by employing an efficient capability based object model that supports both confinement and revocation of these capabilities when the platform security deems it necessary.{SV-AC-6}{AC-3(8),IA-4(9),PM-32,SA-8(2),SA-8(5),SA-8(6),SA-8(18),SA-8(19),SC-2(2),SC-4,SC-16,SC-32,SI-3}
The [spacecraft] shall monitor and collect all onboard cyber-relevant data (from multiple system components), including identification of potential attacks and sufficient information about the attack for subsequent analysis.{SV-DCO-1}{AC-6(9),AC-20,AC-20(1),AU-2,AU-12,IR-4,IR-4(1),RA-10,SI-3,SI-3(10),SI-4,SI-4(1),SI-4(2),SI-4(7),SI-4(24)}	The spacecraft will monitor and collect data that provides accountability of activity occurring onboard the spacecraft. Due to resource limitations on the spacecraft, analysis must be performed to determine which data is critical for retention and which can be filtered. Full system coverage of data and actions is desired as an objective; it will likely be impractical due to the resource limitations. “Cyber-relevant data” refers to all data and actions deemed necessary to support accountability and awareness of onboard cyber activities for the mission. This would include data that may indicate abnormal activities, critical configuration parameters, transmissions on onboard networks, command logging, or other such data items. This set of data items should be identified early in the system requirements and design phase. Cyber-relevant data should support the ability to assess whether abnormal events are unintended anomalies or actual cyber threats. Actual cyber threats may rarely or never occur, but non-threat anomalies occur regularly. The ability to filter out cyber threats for non-cyber threats in relevant time would provide a needed capability. Examples could include successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels).
The [spacecraft] shall provide the capability to modify the set of audited events (e.g., cyber-relevant data).{SV-DCO-1}{AU-12(3),AU-14}
The [spacecraft] shall generate cyber-relevant audit records containing information that establishes what type of event occurred, when the event occurred, where the event occurred, the source of the event, and the outcome of the event.{SV-DCO-1}{AU-3,AU-3(1),AU-12,IR-4,IR-4(1),RA-10,SI-3,SI-3(10),SI-4(7),SI-4(24)}
The [spacecraft] shall be configured to allocate audit record storage capacity in accordance with 1 week audit record storage requirements.{SV-DCO-1}{AU-4,AU-5,AU-5(1),AU-5(2)}
The [spacecraft] shall downlink relevant audit log data to ground systems frequently enough to avoid any situation where audit storage capacity is exceeded.{AU-4(1)}	The frequency of offloading this data depends on the amount of data being audited/logged and will vary across missions/systems.
The [spacecraft] shall attribute cyber attacks and identify unauthorized use of the platform by downlinking onboard cyber information to the mission ground station within 3 minutes. {AU-4(1),IR-4,IR-4(1),IR-4(12),IR-4(13),RA-10,SA-8(22),SI-3,SI-3(10),SI-4(5),SI-4(7),SI-4(12),SI-4(24)}
The [spacecraft] shall attribute cyberattacks and identify unauthorized use of the spacecraft by downlinking onboard cyber information to the mission ground station within [mission-appropriate timelines minutes].{SV-DCO-1}{AU-4(1),SI-4(5)}	Requirement is to support offboard attribution by enabling the fusion of spacecraft cyber data with ground-based cyber data. This would provide end-to-end accountability of commands, data, and other data that can be used to determine the origin of attack from the ground system. Data should be provided within time constraints relevant for the particular mission and its given operational mode. Analysis should be performed to identify the specific timeliness requirements for a mission, which may vary depending on mission mode, operational status, availability of communications resources, and other factors. The specific data required should be identified, as well.
The [spacecraft] shall alert in the event of the [organization]-defined audit/logging processing failures.{SV-DCO-1}{AU-5}
The [spacecraft] shall alert in the event of the audit/logging processing failures.{AU-5,AU-5(1),AU-5(2),SI-3,SI-4,SI-4(1),SI-4(7),SI-4(12),SI-4(24)}
The [spacecraft] shall provide an alert immediately to [at a minimum the mission director, administrators, and security officers] when the following failure events occur: [minimally but not limited to: auditing software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity reaching 95%, 99%, and 100%] of allocated capacity.{SV-DCO-1}{AU-5,AU-5(1),AU-5(2),SI-4,SI-4(1),SI-4(7),SI-4(12),SI-4(24),SI-7(7)}	Intent is to have human on the ground be alerted to failures. This can be decomposed to SV to generate telemetry and to Ground to alert.
The [spacecraft] shall provide the capability of a cyber “black-box” to capture necessary data for cyber forensics of threat signatures and anomaly resolution when cyber attacks are detected.{SV-DCO-1}{AU-5(5),AU-9(2),AU-9(3),AU-12,IR-4(12),IR-4(13),IR-5(1),SI-3,SI-3(10),SI-4,SI-4(1),SI-4(7),SI-4(24),SI-7(7)}	Similar concept of a "black box" on an aircraft where all critical information is stored for post forensic analysis. Black box can be used to record CPU utilization, GNC physical parameters, audit records, memory contents, TT&C data points, etc. The timeframe is dependent upon implementation but needs to meet the intent of the requirement. For example, 30 days may suffice.
The [spacecraft] shall provide automated onboard mechanisms that integrate audit review, analysis, and reporting processes to support mission processes for investigation and response to suspicious activities to determine the attack class in the event of a cyber attack.{SV-DCO-1}{AU-6(1),IR-4,IR-4(1),IR-4(12),IR-4(13),PM-16(1),RA-10,SA-8(21),SA-8(22),SC-5(3),SI-3,SI-3(10),SI-4(7),SI-4(24),SI-7(7)}	* Identifying the class (e.g., exfiltration, Trojans, etc.), nature, or effect of cyberattack (e.g., exfiltration, subverted control, or mission interruption) is necessary to determine the type of response. The first order of identification may be to determine whether the event is an attack or a non-threat event (anomaly). The objective requirement would be to predict the impact of the detected signature. * Unexpected conditions can include RF lockups, loss of lock, failure to acquire an expected contact and unexpected reports of acquisition, unusual AGC and ACS control excursions, unforeseen actuator enabling's or actions, thermal stresses, power aberrations, failure to authenticate, software or counter resets, etc. Mitigation might include additional TMONs, more detailed AGC and PLL thresholds to alert operators, auto-capturing state snapshot images in memory when unexpected conditions occur, signal spectra measurements, and expanded default diagnostic telemetry modes to help in identifying and resolving anomalous conditions.
The [organization] shall integrate terrestrial system audit log analysis as part of the standard anomaly resolution process to correlate any anomalous behavior in the terrestrial systems that correspond to anomalous behavior in the spacecraft.{SV-DCO-1}{AU-6(1),IR-5(1)}
The [spacecraft] shall integrate cyber related detection and responses with existing fault management capabilities to ensure tight integration between traditional fault management and cyber intrusion detection and prevention.{SV-DCO-1}{AU-6(4),IR-4,IR-4(1),RA-10,SA-8(21),SA-8(26),SC-3(4),SI-3,SI-3(10),SI-4(7),SI-4(13),SI-4(16),SI-4(24),SI-4(25),SI-7(7),SI-13}	The onboard IPS system should be integrated into the existing onboard spacecraft fault management system (FMS) because the FMS has its own fault detection and response system built in. SV corrective behavior is usually limited to automated fault responses and ground commanded recovery actions. Intrusion prevention and response methods will inform resilient cybersecurity design. These methods enable detected threat activity to trigger defensive responses and resilient SV recovery.
The [spacecraft] shall record time stamps for audit records that can be mapped to Coordinated Universal Time (UTC) or Greenwich Mean Time (GMT).{SV-DCO-1}{AU-8}
The [spacecraft] shall record time stamps for audit records that provide a granularity of one Z-count (1.5 sec).{SV-DCO-1}{AU-8}
The [spacecraft] shall use internal system clocks to generate time stamps for audit records.{SV-DCO-1}{AU-8}
The [spacecraft] shall protect information obtained from logging/intrusion-monitoring from unauthorized access, modification, and deletion.{SV-DCO-1}{AU-9,AU-9(3),RA-10,SI-4(7),SI-4(24)}
The [spacecraft] shall implement cryptographic mechanisms to protect the integrity of audit information and audit tools.{SV-DCO-1}{AU-9(3),RA-10,SC-8(1),SI-3,SI-3(10),SI-4(24)}
All [spacecraft] commands which have unrecoverable consequence must have dual authentication prior to command execution.{AU-9(5),IA-3,IA-4,IA-10,PE-3,PM-12,SA-8(15),SA-8(21),SC-16(2),SC-16(3),SI-3(8),SI-3(9),SI-4(13),SI-4(25),SI-7(12),SI-10(6),SI-13}
The [spacecraft] shall have a method to ensure the integrity of these commands and validate their authenticity before execution.{AU-9(5),IA-3,IA-4,IA-10,PE-3,PM-12,SA-8(15),SA-8(21),SC-16(2),SC-16(3),SI-3(8),SI-3(9),SI-4(13),SI-4(25),SI-7(12),SI-10(6),SI-13}
The [organization] shall ensure that the allocated security safeguards operate in a coordinated and mutually reinforcing manner.{SV-MA-6}{CA-7(5),PL-7,PL-8(1),SA-8(19)}
The [organization] shall document and design a security architecture using a defense-in-depth approach that allocates the [organization]s defined safeguards to the indicated locations and layers: [Examples include: operating system abstractions and hardware mechanisms to the separate processors in the platform, internal components, and the FSW].{SV-MA-6}{CA-9,PL-7,PL-8,PL-8(1),SA-8(3),SA-8(4),SA-8(7),SA-8(9),SA-8(11),SA-8(13),SA-8(19),SA-8(29),SA-8(30)}
The [spacecraft] shall prevent the installation of Flight Software without verification that the component has been digitally signed using a certificate that is recognized and approved by the ground.{SV-SP-1,SV-SP-3,SV-SP-6,SV-SP-9}{CM-3,CM-3(8),CM-5,CM-5(3),CM-14,SA-8(8),SA-8(31),SA-10(2),SI-3,SI-7(12),SI-7(15)}
The [organization] shall employ automated tools that provide notification to ground operators upon discovering discrepancies during integrity verification.{CM-3(5),CM-6,IR-6,IR-6(2),SA-8(21),SC-51,SI-3,SI-4(7),SI-4(12),SI-4(24),SI-7(2)}
The [spacecraft] shall provide automatic notification to ground operators upon discovering discrepancies during integrity verification.{SV-IT-2}{CM-3(5),SA-8(21),SI-3,SI-4(7),SI-4(12),SI-4(24),SI-7(2)}
The [spacecraft], upon detection of a potential integrity violation, shall provide the capability to [audit the event and alert ground operators].{SV-DCO-1}{CM-3(5),SA-8(21),SI-3,SI-4(7),SI-4(12),SI-4(24),SI-7(8)}	One example would be for bad commands where the system would reject the command and not increment the Vehicle Command Counter (VCC) and include the information in telemetry.
The [spacecraft] shall execute procedures for ensuring that security-relevant hardware, software, and firmware updates uploaded are exactly as specified by the gold copies. {CM-3(5),SA-8(8),SA-8(21),SA-8(31),SA-10(3),SA-10(4),SA-10(6),SI-7(10),SI-7(12)}
The [spacecraft] shall perform an integrity check of software, firmware, and information at startup or during security-relevant events. {CM-3(5),SA-8(9),SA-8(11),SA-8(21),SI-3,SI-7(1),SI-7(10),SI-7(12),SI-7(17)}
The [spacecraft] shall be configured to provide only essential capabilities.{CM-6,CM-7,SA-8(2),SA-8(7),SA-8(13),SA-8(23),SA-8(26),SA-15(5)}
The [spacecraft] shall enter a cyber-safe mode when conditions that threaten the platform are detected, enters a cyber-safe mode of operation with restrictions as defined based on the cyber-safe mode.{SV-AV-5,SV-AV-6,SV-AV-7}{CP-10(6),CP-12,CP-13,IR-4,IR-4(1),IR-4(3),PE-10,RA-10,SA-8(16),SA-8(21),SA-8(24),SI-3,SI-4(7),SI-13,SI-17}
The [spacecraft] shall provide the capability to enter the platform into a known good, operational cyber-safe mode from a tamper-resistant, configuration-controlled (“gold”) image that is authenticated as coming from an acceptable supplier, and has its integrity verified.{SV-AV-5,SV-AV-6,SV-AV-7}{CP-10(6),CP-12,CP-13,IR-4(3),SA-8(16),SA-8(19),SA-8(21),SA-8(24),SI-13,SI-17}	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 SW functions to preattack 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 available equipment still available after a cyberattack. The goal is for the vehicle to resume full mission operations. If not possible, a reduced level of mission capability should be achieved.
The [spacecraft] shall enter cyber-safe mode software/configuration should be stored onboard the spacecraft in memory with hardware-based controls and should not be modifiable.{CP-10(6),CP-13,SA-8(16),SA-8(19),SA-8(21),SA-8(24),SI-17}
The [spacecraft] shall fail to a known secure state for failures during initialization, and aborts preserving information necessary to return to operations in failure.{SV-AV-5,SV-AV-6,SV-AV-7}{CP-10(6),CP-13,SA-8(16),SA-8(19),SA-8(24),SC-24,SI-13,SI-17}
The [organization] shall define the security safeguards that are to be automatically employed when integrity violations are discovered.{SV-IT-2}{CP-2,SA-8(21),SI-3,SI-4(7),SI-4(12),SI-7(5),SI-7(8)}
The [spacecraft] shall recover from cyber-safe mode to mission operations within 20 minutes.{SV-MA-5}{CP-2(3),CP-2(5),IR-4,SA-8(24)}	Upon conclusion of addressing the threat, the system should be capable of recovering from the minimal survival mode back into a mission-ready state within defined timelines. The intent is to define the timelines and the capability to return back to mission operations.
The [spacecraft] shall provide or support the capability for recovery and reconstitution to a known state after a disruption, compromise, or failure.{SV-AV-5,SV-AV-6,SV-AV-7}{CP-4(4),CP-10,CP-10(4),CP-10(6),CP-13,IR-4,IR-4(1),SA-8(16),SA-8(19),SA-8(24)}
The [spacecraft] shall have multiple uplink paths {SV-AV-1}{CP-8,CP-11,SA-8(18),SC-5,SC-47}
The [spacecraft] shall utilize TRANSEC.{SV-AV-1}{CP-8,RA-5(4),SA-8(18),SA-8(19),SC-8(1),SC-8(4),SC-16,SC-16(1),SC-16(2),SC-16(3),SC-40(4)}	Transmission Security (TRANSEC) is used to ensure the availability of transmissions and limit intelligence collection from the transmissions. TRANSEC is secured through burst encoding, frequency hopping, or spread spectrum methods where the required pseudorandom sequence generation is controlled by a cryptographic algorithm and key. Such keys are known as transmission security keys (TSK). The objectives of transmission security are low probability of interception (LPI), low probability of detection (LPD), and antijam which means resistance to jamming (EPM or ECCM).
The [spacecraft] shall be able to locate the onboard origin of a cyber attack and alert ground operators within 3 minutes.{SV-DCO-1}{IR-4,IR-4(1),IR-4(12),IR-4(13),RA-10,SA-8(22),SI-3,SI-3(10),SI-4,SI-4(1),SI-4(7),SI-4(12),SI-4(16),SI-4(24)}	The origin of any attack onboard the vehicle should be identifiable to support mitigation. At the very least, attacks from critical element (safety-critical or higher-attack surface) components should be locatable quickly so that timely action can occur.
The [spacecraft] shall detect and deny unauthorized outgoing communications posing a threat to the spacecraft.{SV-DCO-1}{IR-4,IR-4(1),RA-5(4),RA-10,SC-7(9),SC-7(10),SI-4,SI-4(1),SI-4(4),SI-4(7),SI-4(11),SI-4(13),SI-4(24),SI-4(25)}
The [spacecraft] shall recover to a known cyber-safe state when an anomaly is detected.{IR-4,IR-4(1),SA-8(16),SA-8(19),SA-8(21),SA-8(24),SI-3,SI-4(7),SI-10(6),SI-13,SI-17}
The [spacecraft] shall detect and recover from detected memory errors or transitions to a known cyber-safe state.{IR-4,IR-4(1),SA-8(16),SA-8(24),SI-3,SI-4(7),SI-10(6),SI-13,SI-17}
The [spacecraft] shall select and execute safe countermeasures against cyber attacks prior to entering cyber-safe mode.{SV-DCO-1}{IR-4,RA-10,SA-8(21),SA-8(24),SI-4(7),SI-17}	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 exquisitely—with or without ground aiding. 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." These countermeasures are likely executed prior to entering into a cyber-safe mode.
The [spacecraft] shall provide cyber threat status to the ground segment for the Defensive Cyber Operations team, per the governing specification.{SV-DCO-1}{IR-5,PM-16,PM-16(1),RA-3(3),RA-10,SI-4,SI-4(1),SI-4(24),SI-7(7)}	The future space enterprises will include full-time Cyber Defense teams supporting space mission systems. Their work is currently focused on the ground segment but may eventually require specific data from the space segment for their successful operation. This requirement is a placeholder to ensure that any DCO-related requirements are taken into consideration for this document.
The [spacecraft] shall perform an orderly, controlled system shut-down to a known cyber-safe state upon receipt of a termination command or condition.{PE-11,PE-11(1),SA-8(16),SA-8(19),SA-8(24),SI-17}
The [spacecraft] shall operate securely in off-nominal power conditions, including loss of power and spurious power transients.{PE-11,PE-11(1),SA-8(16),SA-8(19),SI-13,SI-17}
The [organization] shall implement a security architecture and design that provides the required security functionality, allocates security controls among physical and logical components, and integrates individual security functions, mechanisms, and processes together to provide required security capabilities and a unified approach to protection.{SV-MA-6}{PL-7,SA-2,SA-8,SA-8(1),SA-8(2),SA-8(3),SA-8(4),SA-8(5),SA-8(6),SA-8(7),SA-8(9),SA-8(11),SA-8(13),SA-8(19),SA-8(29),SA-8(30),SC-32,SC-32(1)}
The [spacecraft] shall be designed and configured so that encrypted communications traffic and data is visible to on-board security monitoring tools.{SV-DCO-1}{RA-10,SA-8(21),SI-3,SI-3(10),SI-4,SI-4(1),SI-4(10),SI-4(13),SI-4(24),SI-4(25)}
The [spacecraft] shall be designed and configured so that spacecraft memory can be monitored by the on-board intrusion detection/prevention capability.{SV-DCO-1}{RA-10,SA-8(21),SI-3,SI-3(10),SI-4,SI-4(1),SI-4(24),SI-16}
The [spacecraft] shall have on-board intrusion detection/prevention system that monitors the mission critical components or systems.{SV-AC-1,SV-AC-2,SV-MA-4}{RA-10,SC-7,SI-3,SI-3(8),SI-4,SI-4(1),SI-4(7),SI-4(13),SI-4(24),SI-4(25),SI-10(6)}	The mission critical components or systems could be GNC/Attitude Control, C&DH, TT&C, Fault Management.
The [spacecraft] shall employ advanced analytics capabilities within the IDS/IPS to address dynamic never-before-seen attacks using machine learning/adaptive technologies along with signature-based attacks.{RA-3(4)}
The [spacecraft] shall retain the capability to update/upgrade operating systems while on-orbit.{SV-SP-7}{SA-4(5),SA-8(8),SA-8(31),SA-10(2),SI-3}	The operating system updates should be performed using multi-factor authorization and should only be performed when risk of compromise/exploitation of identified vulnerability outweighs the risk of not performing the update.
The [spacecraft] shall perform attestation at each stage of startup and ensure overall trusted boot regime (i.e., root of trust).{SV-IT-3}{SA-8(10),SA-8(11),SA-8(12),SI-7(9),SI-7(10),SI-7(17)}	It is important for the computing module to be able to access a set of functions and commands that it trusts; that is, that it knows to be true. This concept is referred to as root of trust (RoT) and should be included in the spacecraft design. With RoT, a device can always be trusted to operate as expected. RoT functions, such as verifying the device’s own code and configuration, must be implemented in secure hardware (i.e., field programmable gate arrays). By checking the security of each stage of power-up, RoT devices form the first link in a chain of trust that protects the spacecraft
The [spacecraft] shall maintain a separate execution domain for each executing process.{SV-AC-6}{SA-8(14),SA-8(19),SC-2(2),SC-7(21),SC-39,SI-3}
The [spacecraft] shall initialize the platform to a known safe state.{SA-8(19),SA-8(23),SA-8(24),SI-17}
The [spacecraft] shall provide the capability to verify the correct operation of security-relevant software and hardware mechanisms (e.g.spacecraft IDS/IPS, logging, crypto, etc..) {SV-DCO-1}{SA-8(21),SI-3,SI-6}
The [organization] shall define and document the transitional state or security-relevant events when the spacecraft will perform integrity checks on software, firmware, and information.{SV-IT-2}{SA-8(21),SI-7(1),SI-7(10),SR-4(4)}
The [spacecraft] shall discriminate between valid and invalid input into the software and rejects invalid input.{SC-16(2),SI-3(8),SI-10,SI-10(3),SI-10(6)}
The [spacecraft] shall identify and reject commands received out-of-sequence when the out-of-sequence commands can cause a hazard/failure or degrade the control of a hazard or mission.{SC-16(2),SI-4(13),SI-4(25),SI-10,SI-10(6),SI-13}
The [spacecraft] shall provide independent mission/cyber critical threads such that any one credible event will not corrupt another mission/cyber critical thread.{SC-3,SC-32,SC-32(1),SI-3,SI-13}
The [spacecraft] shall implement protections against external and internal communications from jamming attempts.{SC-5,SC-40,SC-40(1)}
The [spacecraft] shall protect external and internal communications from jamming and spoofing attempts.{SV-AV-1,SV-IT-1}{SC-5,SC-40,SC-40(1)}	Can be aided via the Crosslink, S-Band, and L-Band subsystems
The [organization] shall define the security safeguards to be employed to protect the availability of system resources.{SV-AC-6}{SC-6,SI-17}
The [spacecraft] shall monitor [Program defined telemetry points] for malicious commanding attempts.{SV-AC-1,SV-AC-2}{SC-7,AU-3(1),AC-17(1)}	Source from AEROSPACE REPORT NO. TOR-2019-02178 Vehicle Command Counter (VCC) - Counts received valid commands Rejected Command Counter - Counts received invalid commands Command Receiver On/Off Mode - Indicates times command receiver is accepting commands Command Receivers Received Signal Strength - Analog measure of the amount of received RF energy at the receive frequency Command Receiver Lock Modes - Indicates when command receiver has achieved lock on command signal Telemetry Downlink Modes - Indicates when the satellite’s telemetry was transmitting Cryptographic Modes - Indicates the operating modes of the various encrypted links Received Commands - Log of all commands received and executed by the satellite System Clock - Master onboard clock GPS Ephemeris - Indicates satellite location derived from GPS Signals
The [spacecraft] shall audit the communications characteristics (signals, frequencies, etc.) associated with denied communications.{SC-7(9)}
The [spacecraft] shall properly handle spurious input and missing data.{SI-10,SI-10(3),SI-10(6)}
The [spacecraft] shall perform prerequisite checks for the execution of hazardous commands.{SI-10,SI-10(6),SI-13}
The [spacecraft] shall validate a functionally independent parameter prior to the issuance of any sequence that could remove an inhibit, or perform a hazardous action.{SI-10(3),SI-10(6),SI-13}
The [spacecraft] shall have failure tolerance on sensors used by software to make mission-critical decisions.{SV-MA-3,SV-AV-7}{SI-13,SI-17}
The [spacecraft] fault management solution shall utilize memory uncorrectable bit error detection information in a strategy to autonomously minimize the adverse effects of uncorrectable bit errors within the spacecraft.{SV-IT-4}{SI-16}
The [spacecraft] Interrupt Service Routine (ISR) shall have the ability to simultaneously update check-bits for [organization]-defined memory addresses.{SV-IT-4}{SI-16}
The [spacecraft] shall integrate EDAC scheme with fault management and cyber-protection mechanisms to respond to the detection of uncorrectable multi-bit errors, other than time-delayed monitoring of EDAC telemetry by the mission operators on the ground.{SV-IT-4}{SI-16}
The [spacecraft] shall use Error Detection and Correcting (EDAC) memory.{SV-IT-4}{SI-16}
The [spacecraft] shall utilize an EDAC scheme to routinely check for bit errors in the stored data on board the spacecraft, correct the single-bit errors, and identify the memory addresses of data with uncorrectable multi-bit errors of at least order two, if not higher order in some cases.{SV-IT-4}{SI-16}
The [spacecraft] cyber-safe mode software/configuration should be stored onboard the spacecraft in memory with hardware-based controls and should not be modifiable.{SV-AV-5,SV-AV-6,SV-AV-7}{SI-17}	Cyber-safe mode is using a fail-secure mentality where if there is a malfunction that the spacecraft goes into a fail-secure state where cyber protections like authentication and encryption are still employed (instead of bypassed) and the spacecraft can be restored by authorized commands. The cyber-safe mode should be stored in a high integrity location of the on-board SV so that it cannot be modified by attackers.
The [spacecraft] shall safely transition between all predefined, known states.{SI-17}
The [spacecraft] software subsystems shall detect and recover/transition from detected memory errors to a known cyber-safe state.{SV-MA-3,SV-AV-7}{SI-17}
The [spacecraft] software subsystems shall initialize the spacecraft to a known safe state.{SV-MA-3,SV-AV-7}{SI-17}
The [spacecraft] software subsystems shall operate securely in off-nominal power conditions, including loss of power and spurious power transients.{SV-MA-3,SV-AV-7}{SI-17}
The [spacecraft] software subsystems shall perform an orderly, controlled system shutdown to a known cyber-safe state upon receipt of a termination command or condition.{SV-MA-3,SV-AV-7}{SI-17}
The [spacecraft] software subsystems shall recover to a known cyber-safe state when an anomaly is detected.{SV-MA-3,SV-AV-7}{SI-17}
The [spacecraft] software subsystems shall safely transition between all predefined, known states.{SV-MA-3,SV-AV-7}{SI-17}
The [spacecraft] shall only use or include critical commands for the purpose of providing emergency access where commanding authority is appropriately restricted.{SI-3(8),SI-10,SI-10(3)}
The [spacecraft] shall monitor all inbound/outbound communications to detect unusual or unauthorized behavior and respond appropriately (disregard command, deny connection, etc.){SI-4(4)}
The [spacecraft] shall automatically [Selection (one or more):restarts the FSW/processor, performs side swap, audits failure; implements Program-defined security safeguards] when integrity violations are discovered.{SV-IT-2}{SI-7(8)}