AC-4(31) - Information Flow Enforcement | Failed Content Transfer Prevention

When transferring information between different security domains, prevent the transfer of failed content to the receiving domain.


Informational References

ISO 27001

ID: AC-4(31)
Enhancement of : AC-4

Countermeasures Covered by Control

ID Name Description D3FEND
CM0050 On-board Message Encryption In addition to authentication on-board the spacecraft bus, encryption is also recommended to protect the confidentiality of the data traversing the bus. D3-MH D3-MENCR D3-ET
CM0005 Ground-based Countermeasures This countermeasure is focused on the protection of terrestrial assets like ground networks and development environments/contractor networks, etc. Traditional detection technologies and capabilities would be applicable here. Utilizing resources from NIST CSF to properly secure these environments using identify, protect, detect, recover, and respond is likely warranted. Additionally, NISTIR 8401 may provide resources as well since it was developed to focus on ground-based security for space systems (https://nvlpubs.nist.gov/nistpubs/ir/2022/NIST.IR.8401.ipd.pdf). Furthermore, the MITRE ATT&CK framework provides IT focused TTPs and their mitigations https://attack.mitre.org/mitigations/enterprise/. Several recommended NIST 800-53 Rev5 controls are provided for reference when designing ground systems/networks. Nearly all D3FEND Techniques apply to Ground
CM0038 Segmentation Identify the key system components or capabilities that require isolation through physical or logical means. Information should not be allowed to flow between partitioned applications unless explicitly permitted by security policy. Isolate mission critical functionality from non-mission critical functionality by means of an isolation boundary (implemented via partitions) that controls access to and protects the integrity of, the hardware, software, and firmware that provides that functionality. Enforce approved authorizations for controlling the flow of information within the spacecraft and between interconnected systems based on the defined security policy that information does not leave the spacecraft boundary unless it is encrypted. Implement boundary protections to separate bus, communications, and payload components supporting their respective functions. D3-NI D3-BDI D3-NTF D3-ITF D3-OTF D3-EI D3-HBPI D3-KBPI D3-MAC D3-RRID D3-EAL D3-EDL D3-IOPR D3-SCF

Space Threats Tagged by Control

ID Description
SV-IT-2 Unauthorized modification or corruption of data
SV-MA-7 Exploit ground system and use to maliciously to interact with the spacecraft

Sample Requirements

Requirement Rationale/Additional Guidance/Notes

Related SPARTA Techniques and Sub-Techniques

ID Name Description
REC-0001 Gather Spacecraft Design Information Threat actors may gather information about the victim spacecraft's design that can be used for future campaigns or to help perpetuate other techniques. Information about the spacecraft can include software, firmware, encryption type, purpose, as well as various makes and models of subsystems.
REC-0001.01 Software Threat actors may gather information about the victim spacecraft's internal software that can be used for future campaigns or to help perpetuate other techniques. Information (e.g. source code, binaries, etc.) about commercial, open-source, or custom developed software may include a variety of details such as types, versions, and memory maps. Leveraging this information threat actors may target vendors of operating systems, flight software, or open-source communities to embed backdoors or for performing reverse engineering research to support offensive cyber operations.
REC-0001.02 Firmware Threat actors may gather information about the victim spacecraft's firmware that can be used for future campaigns or to help perpetuate other techniques. Information about the firmware may include a variety of details such as type and versions on specific devices, which may be used to infer more information (ex. configuration, purpose, age/patch level, etc.). Leveraging this information threat actors may target firmware vendors to embed backdoors or for performing reverse engineering research to support offensive cyber operations.
REC-0001.03 Cryptographic Algorithms Threat actors may gather information about any cryptographic algorithms used on the victim spacecraft's that can be used for future campaigns or to help perpetuate other techniques. Information about the algorithms can include type and private keys. Threat actors may also obtain the authentication scheme (i.e., key/password/counter values) and leverage it to establish communications for commanding the target spacecraft or any of its subsystems. Some spacecraft only require authentication vice authentication and encryption, therefore once obtained, threat actors may use any number of means to command the spacecraft without needing to go through a legitimate channel. The authentication information may be obtained through reconnaissance of the ground system or retrieved from the victim spacecraft.
REC-0001.04 Data Bus Threat actors may gather information about the data bus used within the victim spacecraft that can be used for future campaigns or to help perpetuate other techniques. Information about the data bus can include the make and model which could lead to more information (ex. protocol, purpose, controller, etc.), as well as locations/addresses of major subsystems residing on the bus. Threat actors may also gather information about the bus voltages of the victim spacecraft. This information can include optimal power levels, connectors, range, and transfer rate.
REC-0001.05 Thermal Control System Threat actors may gather information about the thermal control system used with the victim spacecraft that can be used for future campaigns or to help perpetuate other techniques. Information gathered can include type, make/model, and varies analysis programs that monitor it.
REC-0001.06 Maneuver & Control Threat actors may gather information about the station-keeping control systems within the victim spacecraft that can be used for future campaigns or to help perpetuate other techniques. Information gathered can include thruster types, propulsion types, attitude sensors, and data flows associated with the relevant subsystems.
REC-0001.07 Payload Threat actors may gather information about the type(s) of payloads hosted on the victim spacecraft. This information could include specific commands, make and model, and relevant software. Threat actors may also gather information about the location of the payload on the bus and internal routing as it pertains to commands within the payload itself.
REC-0001.08 Power Threat actors may gather information about the power system used within the victim spacecraft. This information can include type, power intake, and internal algorithms. Threat actors may also gather information about the solar panel configurations such as positioning, automated tasks, and layout. Additionally, threat actors may gather information about the batteries used within the victim spacecraft. This information can include the type, quantity, storage capacity, make and model, and location.
REC-0001.09 Fault Management Threat actors may gather information about any fault management that may be present on the victim spacecraft. This information can help threat actors construct specific attacks that may put the spacecraft into a fault condition and potentially a more vulnerable state depending on the fault response.
REC-0002 Gather Spacecraft Descriptors Threat actors may gather information about the victim spacecraft's descriptors that can be used for future campaigns or to help perpetuate other techniques. Information about the descriptors may include a variety of details such as identity attributes, organizational structures, and mission operational parameters.
REC-0002.01 Identifiers Threat actors may gather information about the victim spacecraft's identity attributes that can be used for future campaigns or to help perpetuate other techniques. Information may include a variety of details such as the satellite catalog number, international designator, mission name, and more.
REC-0002.02 Organization Threat actors may gather information about the victim spacecraft's associated organization(s) that can be used for future campaigns or to help perpetuate other techniques. Collection efforts may target the mission owner/operator in order to conduct further attacks against the organization, individual, or other interested parties. Threat actors may also seek information regarding the spacecraft's designer/builder, including physical locations, key employees, and roles and responsibilities as they pertain to the spacecraft, as well as information pertaining to the mission's end users/customers.
REC-0002.03 Operations Threat actors may gather information about the victim spacecraft's operations that can be used for future campaigns or to help perpetuate other techniques. Collection efforts may target mission objectives, orbital parameters such as orbit slot and inclination, user guides and schedules, etc. Additionally, threat actors may seek information about constellation deployments and configurations where applicable.
REC-0003 Gather Spacecraft Communications Information Threat actors may obtain information on the victim spacecraft's communication channels in order to determine specific commands, protocols, and types. Information gathered can include commanding patterns, antenna shape and location, beacon frequency and polarization, and various transponder information.
REC-0003.01 Communications Equipment Threat actors may gather information regarding the communications equipment and its configuration that will be used for communicating with the victim spacecraft. This includes: Antenna Shape: This information can help determine the range in which it can communicate, the power of it's transmission, and the receiving patterns. Antenna Configuration/Location: This information can include positioning, transmission frequency, wavelength, and timing. Telemetry Signal Type: Information can include timing, radio frequency wavelengths, and other information that can provide insight into the spacecraft's telemetry system. Beacon Frequency: This information can provide insight into where the spacecrafts located, what it's orbit is, and how long it can take to communicate with a ground station. Beacon Polarization: This information can help triangulate the spacecrafts it orbits the earth and determine how a satellite must be oriented in order to communicate with the victim spacecraft. Transponder: This could include the number of transponders per band, transponder translation factor, transponder mappings, power utilization, and/or saturation point.
REC-0003.02 Commanding Details Threat actors may gather information regarding the commanding approach that will be used for communicating with the victim spacecraft. This includes: Commanding Signal Type: This can include timing, radio frequency wavelengths, and other information that can provide insight into the spacecraft's commanding system. Valid Commanding Patterns: Most commonly, this comes in the form of a command database, but can also include other means that provide information on valid commands and the communication protocols used by the victim spacecraft. Valid Commanding Periods: This information can provide insight into when a command will be accepted by the spacecraft and help the threat actor construct a viable attack campaign.
REC-0003.03 Mission-Specific Channel Scanning Threat actors may seek knowledge about mission-specific communication channels dedicated to a payload. Such channels could be managed by a different organization than the owner of the spacecraft itself.
REC-0003.04 Valid Credentials Threat actors may seek out valid credentials which can be utilized to facilitate several tactics throughout an attack. Credentials may include, but are not limited to: system service accounts, user accounts, maintenance accounts, cryptographic keys and other authentication mechanisms.
REC-0004 Gather Launch Information Threat actors may gather the launch date and time, location of the launch (country & specific site), organizations involved, launch vehicle, etc. This information can provide insight into protocols, regulations, and provide further targets for the threat actor, including specific vulnerabilities with the launch vehicle itself.
REC-0004.01 Flight Termination Threat actor may obtain information regarding the vehicle's flight termination system. Threat actors may use this information to perform later attacks and target the vehicle's termination system to have desired impact on mission.
REC-0006 Gather FSW Development Information Threat actors may obtain information regarding the flight software (FSW) development environment for the victim spacecraft. This information may include the development environment, source code, compiled binaries, testing tools, and fault management.
REC-0006.01 Development Environment Threat actors may gather information regarding the development environment for the victim spacecraft's FSW. This information can include IDEs, configurations, source code, environment variables, source code repositories, code "secrets", and compiled binaries.
REC-0006.02 Security Testing Tools Threat actors may gather information regarding how a victim spacecraft is tested in regards to the FSW. Understanding the testing approach including tools could identify gaps and vulnerabilities that could be discovered and exploited by a threat actor.
REC-0007 Monitor for Safe-Mode Indicators Threat actors may gather information regarding safe-mode indicators on the victim spacecraft. 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.
REC-0008 Gather Supply Chain Information Threat actors may gather information about a mission's supply chain or product delivery mechanisms that can be used for future campaigns or to help perpetuate other techniques.
REC-0008.01 Hardware Threat actors may gather information that can be used to facilitate a future attack where they manipulate hardware components in the victim spacecraft prior to the customer receiving them in order to achieve data or system compromise. The threat actor can insert backdoors and give them a high level of control over the system when they modify the hardware or firmware in the supply chain. This would include ASIC and FPGA devices as well.
REC-0008.02 Software Threat actors may gather information relating to the mission's software supply chain in order to facilitate future attacks to achieve data or system compromise. This attack can take place in a number of ways, including manipulation of source code, manipulation of the update and/or distribution mechanism, or replacing compiled versions with a malicious one.
REC-0008.03 Known Vulnerabilities Threat actors may gather information about vulnerabilities that can be used for future campaigns or to perpetuate other techniques. A vulnerability is a weakness in the victim spacecraft's hardware, subsystems, bus, or software that can, potentially, be exploited by a threat actor to cause unintended or unanticipated behavior to occur. During reconnaissance as threat actors identify the types/versions of software (i.e., COTS, open-source) being used, they will look for well-known vulnerabilities that could affect the spacecraft. Threat actors may find vulnerability information by searching leaked documents, vulnerability databases/scanners, compromising ground systems, and searching through online databases.
REC-0008.04 Business Relationships Adversaries may gather information about the victim's business relationships that can be used during targeting. Information about an mission’s business relationships may include a variety of details, including second or third-party organizations/domains (ex: managed service providers, contractors/sub-contractors, etc.) that have connected (and potentially elevated) network access or sensitive information. This information may also reveal supply chains and shipment paths for the victim’s hardware and software resources.
REC-0009 Gather Mission Information Threat actors may initially seek to gain an understanding of a target mission by gathering information commonly captured in a Concept of Operations (or similar) document and related artifacts. Information of interest includes, but is not limited to: - the needs, goals, and objectives of the system - system overview and key elements/instruments - modes of operations (including operational constraints) - proposed capabilities and the underlying science/technology used to provide capabilities (i.e., scientific papers, research studies, etc.) - physical and support environments
RD-0002 Compromise Infrastructure Threat actors may compromise third-party infrastructure that can be used for future campaigns or to perpetuate other techniques. Infrastructure solutions include physical devices such as antenna, amplifiers, and convertors, as well as software used by satellite communicators. Instead of buying or renting infrastructure, a threat actor may compromise infrastructure and use it during other phases of the campaign's lifecycle.
RD-0002.01 Mission-Operated Ground System Threat actors may compromise mission owned/operated ground systems that can be used for future campaigns 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 an operation. Threat actors may utilize these systems for various tasks, including Execution and Exfiltration.
RD-0002.02 3rd Party Ground System Threat actors may compromise access to third-party ground systems that can be used for future campaigns or to perpetuate other techniques. These ground systems can be or may have already been configured for communications to the victim spacecraft. By compromising this infrastructure, threat actors can stage, launch, and execute an operation.
RD-0003 Obtain Cyber Capabilities Threat actors may buy and/or steal cyber capabilities that can be used for future campaigns or to perpetuate other techniques. Rather than developing their own capabilities in-house, threat actors may purchase, download, or steal them. Activities may include the acquisition of malware, software, exploits, and information relating to vulnerabilities. Threat actors may obtain capabilities to support their operations throughout numerous phases of the campaign lifecycle.
RD-0003.02 Cryptographic Keys Threat actors may obtain encryption keys as they are used for the main commanding of the target spacecraft or any of its subsystems/payloads. Once obtained, threat actors may use any number of means to command the spacecraft without needing to go through a legitimate channel. These keys may be obtained through reconnaissance of the ground system or retrieved from the victim spacecraft.
RD-0004 Stage Capabilities Threat actors may upload, install, or otherwise set up capabilities that can be used for future campaigns or to perpetuate other techniques. To support their operations, a threat actor may need to develop their own capabilities or obtain them in some way in order to stage them on infrastructure under their control. These capabilities may be staged on infrastructure that was previously purchased or rented by the threat actor or was otherwise compromised by them.
RD-0004.01 Identify/Select Delivery Mechanism Threat actors may identify, select, and prepare a delivery mechanism in which to attack the space system (i.e., communicate with the victim spacecraft, deny the ground, etc.) to achieve their desired impact. This mechanism may be located on infrastructure that was previously purchased or rented by the threat actor or was otherwise compromised by them. The mechanism must include all aspects needed to communicate with the victim spacecraft, including ground antenna, converters, and amplifiers.
RD-0004.02 Upload Exploit/Payload Threat actors may upload exploits and payloads to a third-party infrastructure that they have purchased or rented or stage it on an otherwise compromised ground station. Exploits and payloads would include files and commands to be uploaded to the victim spacecraft in order to conduct the threat actor's attack.
IA-0002 Compromise Software Defined Radio Threat actors may target software defined radios due to their software nature to establish C2 channels. Since SDRs are programmable, when combined with supply chain or development environment attacks, SDRs provide a pathway to setup covert C2 channels for a threat actor.
IA-0004 Secondary/Backup Communication Channel Threat actors may compromise alternative communication pathways which may not be as protected as the primary pathway. Depending on implementation the contingency communication pathways/solutions may lack the same level of security (i.e., physical security, encryption, authentication, etc.) which if forced to use could provide a threat actor an opportunity to launch attacks. Typically these would have to be coupled with other denial of service techniques on the primary pathway to force usage of secondary pathways.
IA-0004.01 Ground Station Threat actors may establish a foothold within the backup ground/mission operations center (MOC) and then perform attacks to force primary communication traffic through the backup communication channel so that other TTPs can be executed (man-in-the-middle, malicious commanding, malicious code, etc.). While an attacker would not be required to force the communications through the backup channel vice waiting until the backup is used for various reasons. Threat actors can also utilize compromised ground stations to chain command execution and payload delivery across geo-separated ground stations to extend reach and maintain access on spacecraft. The backup ground/MOC should be considered a viable attack vector and the appropriate/equivalent security controls from the primary communication channel should be on the backup ground/MOC as well.
IA-0005 Rendezvous & Proximity Operations Threat actors may perform a space rendezvous which is a set of orbital maneuvers during which a spacecraft arrives at the same orbit and approach to a very close distance (e.g. within visual contact or close proximity) to a target spacecraft.
IA-0005.02 Docked Vehicle / OSAM Threat actors may leverage docking vehicles to laterally move into a target spacecraft. If information is known on docking plans, a threat actor may target vehicles on the ground or in space to deploy malware to laterally move or execute malware on the target spacecraft via the docking interface.
IA-0005.03 Proximity Grappling Threat actors may posses the capability to grapple target spacecraft once it has established the appropriate space rendezvous. If from a proximity / rendezvous perspective a threat actor has the ability to connect via docking interface or expose testing (i.e., JTAG port) once it has grappled the target spacecraft, they could perform various attacks depending on the access enabled via the physical connection.
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.
IA-0007.01 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.
IA-0007.02 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-0009 Trusted Relationship Access through trusted third-party relationship exploits an existing connection that has been approved for interconnection. Leveraging third party / approved interconnections to pivot into the target systems is a common technique for threat actors as these interconnections typically lack stringent access control due to the trusted status.
IA-0009.01 Mission Collaborator (academia, international, etc.) Threat actors may seek to exploit mission partners to gain an initial foothold for pivoting into the mission environment and eventually impacting the spacecraft. The complex nature of many space systems rely on contributions across organizations, including academic partners and even international collaborators. These organizations will undoubtedly vary in their system security posture and attack surface.
IA-0009.02 Vendor Threat actors may target the trust between vendors and the target spacecraft. Missions often grant elevated access to vendors in order to allow them to manage internal systems as well as cloud-based environments. The vendor's access may be intended to be limited to the infrastructure being maintained but it may provide laterally movement into the target spacecraft. Attackers may leverage security weaknesses in the vendor environment to gain access to more critical mission resources or network locations. In the spacecraft context vendors may have direct commanding and updating capabilities outside of the primary communication channel.
IA-0009.03 User Segment Threat actors can target the user segment in an effort to laterally move into other areas of the end-to-end mission architecture. When user segments are interconnected, threat actors can exploit lack of segmentation as the user segment's security undoubtedly varies in their system security posture and attack surface than the primary space mission. The user equipment and users themselves provide ample attack surface as the human element and their vulnerabilities (i.e., social engineering, phishing, iOT) are often the weakest security link and entry point into many systems.
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.
IA-0012 Assembly, Test, and Launch Operation Compromise Threat actors may target the spacecraft hardware and/or software while the spacecraft is at Assembly, Test, and Launch Operation (ATLO). ATLO is often the first time pieces of the spacecraft are fully integrated and exchanging data across interfaces. Malware could propagate from infected devices across the integrated spacecraft. For example, test equipment (i.e., transient cyber asset) is often brought in for testing elements of the spacecraft. Additionally, varying levels of physical security is in place which may be a reduction in physical security typically seen during development. The ATLO environment should be considered a viable attack vector and the appropriate/equivalent security controls from the primary development environment should be implemented during ATLO as well.
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.
EX-0001.02 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-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.
EX-0012.01 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.
EX-0012.02 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.
EX-0012.03 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.
EX-0012.04 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.
EX-0012.05 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.
EX-0012.06 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.
EX-0012.07 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.
EX-0012.08 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.
EX-0012.09 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.
EX-0012.10 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.
EX-0012.11 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.
EX-0012.12 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.
EX-0012.13 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-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.
EX-0014.02 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.
EX-0014.03 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.
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-0005 Valid Credentials Threat actors may seek out valid credentials which can be utilized to maintain persistent access to the spacecraft or related C2 systems and facilitate additional tactics throughout an attack. Credentials may include, but are not limited to: system service accounts, user accounts, maintenance accounts, cryptographic keys and other authentication mechanisms.
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.
DE-0002.01 Inhibit Ground System Functionality Threat actors may utilize ground-system presence to inhibit the ground system software's ability to process (or display) telemetry, 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-0004 Masquerading Threat actors may gain access to a victim spacecraft by masquerading as an authorized entity. This can be done several ways, including through the manipulation of command headers, spoofing locations, or even leveraging Insider's access (i.e., Insider Threat)
DE-0011 Valid Credentials Threat actors may utilize valid credentials to conduct an attack against a spacecraft or related system as a means to conceal their activity. Credentials may include, but are not limited to: system service accounts, user accounts, maintenance accounts, cryptographic keys and other authentication mechanisms.
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-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.
LM-0005 Virtualization Escape In virtualized environments, threat actors can use the open ports between the partitions to overcome the hypervisor's protection and damage another partition. Further, if the threat actor has compromised the payload, access to a critical partition can be gained through ports allowed by hypervisor.
LM-0006 Launch Vehicle Interface Threat actors may attempt to exploit reduced protections placed on the interfaces between launch vehicles and payloads in order to move from one to the other.
LM-0006.01 Rideshare Payload Threat actors may also attempt to move laterally across the payloads themselves in cases where multiple customers are sharing the same launch vehicle, and security mechanisms are not sufficient to prevent payload to payload communication via the launch vehicle.
LM-0007 Valid Credentials Threat actors may utilize valid credentials move laterally across spacecraft subsystems, communication buses, or additional spacecraft in a constellation. Credentials may include, but are not limited to: system service accounts, user accounts, maintenance accounts, cryptographic keys and other authentication mechanisms.
EXF-0002 Side-Channel Attack Threat actors may use a side-channel attack attempts to gather information by measuring or exploiting indirect effects of the spacecraft. Information within the spacecraft can be extracted through these side-channels in which sensor data is analyzed in non-trivial ways to recover subtle, hidden or unexpected information. A series of measurements of a side-channel constitute an identifiable signature which can then be matched against a signature database to identify target information, without having to explicitly decode the side-channel.
EXF-0002.02 Electromagnetic Leakage Attacks Threat actors can leverage electromagnetic emanations to obtain sensitive information. The electromagnetic radiations attain importance when they are hardware generated emissions, especially emissions from the cryptographic module. Electromagnetic leakage attacks have been shown to be more successful than power analysis attacks on chicards. If proper protections are not in place on the spacecraft, the circuitry is exposed and hence leads to stronger emanations of EM radiations. If the circuitry is exposed, it provides an easier environment to study the electromagnetic emanations from each individual component.
EXF-0002.03 Traffic Analysis Attacks In a terrestrial environment, threat actors use traffic analysis attacks to analyze traffic flow to gather topological information. This traffic flow can divulge information about critical nodes, such as the aggregator node in a sensor network. In the space environment, specifically with relays and constellations, traffic analysis can be used to understand the energy capacity of spacecraft node and the fact that the transceiver component of a spacecraft node consumes the most power. The spacecraft nodes in a constellation network limit the use of the transceiver to transmit or receive information either at a regulated time interval or only when an event has been detected. This generally results in an architecture comprising some aggregator spacecraft nodes within a constellation network. These spacecraft aggregator nodes are the sensor nodes whose primary purpose is to relay transmissions from nodes toward the ground station in an efficient manner, instead of monitoring events like a normal node. The added functionality of acting as a hub for information gathering and preprocessing before relaying makes aggregator nodes an attractive target to side channel attacks. A possible side channel attack could be as simple as monitoring the occurrences and duration of computing activities at an aggregator node. If a node is frequently in active states (instead of idle states), there is high probability that the node is an aggregator node and also there is a high probability that the communication with the node is valid. Such leakage of information is highly undesirable because the leaked information could be strategically used by threat actors in the accumulation phase of an attack.
EXF-0003 Eavesdropping Threat actors may seek to capture network communications throughout the ground station and communication channel (i.e. radio frequency, optical) used for uplink and downlink communications
EXF-0003.01 Uplink Intercept Threat actors may target the uplink connection from the victim ground infrastructure to the target spacecraft in order to exfiltrate commanding data. Depending on the implementation (i.e., encryption) the captured uplink data can be used to further other attacks like command link intrusion, replay, etc.
EXF-0003.02 Downlink Intercept Threat actors may target the downlink connection from the victim spacecraft in order to exfiltrate telemetry or payload data. This data can include health information of the spacecraft or mission data that is being collected/analyzed on the spacecraft. Downlinked data can even include mirrored command sessions which can be used for future campaigns or to help perpetuate other techniques.
EXF-0006 Modify Communications Configuration Threat actors can manipulate communications equipment, modifying the existing software, hardware, or the transponder configuration to exfiltrate data via unintentional channels the mission has no control over.
EXF-0006.01 Software Defined Radio Threat actors may target software defined radios due to their software nature to setup exfiltration channels. Since SDRs are programmable, when combined with supply chain or development environment attacks, SDRs provide a pathway to setup covert exfiltration channels for a threat actor.
EXF-0006.02 Transponder Threat actors may change the transponder configuration to exfiltrate data via radio access to an attacker-controlled asset.
EXF-0007 Compromised Ground System Threat actors may compromise target owned ground systems that can be used for future campaigns 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 an operation. Threat actors may utilize these systems for various tasks, including Execution and Exfiltration.
EXF-0008 Compromised Developer Site Threat actors may compromise development environments located within the ground system or a developer/partner site. This attack can take place in a number of different ways, including manipulation of source code, manipulating environment variables, or replacing compiled versions with a malicious one. This technique is usually performed before the target spacecraft is in orbit, with the hopes of adding malicious code to the actual FSW during the development process.
EXF-0009 Compromised Partner Site Threat actors may compromise access to partner sites that can be used for future campaigns or to perpetuate other techniques. These sites are typically configured for communications to the primary ground station(s) or in some cases the spacecraft itself. Unlike mission operated ground systems, partner sites may provide an easier target for threat actors depending on the company, roles and responsibilities, and interests of the third-party. 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.
EXF-0010 Payload Communication Channel Threat actors can deploy malicious software on the payload(s) which can send data through the payload channel. Payloads often have their own communication channels outside of the main TT&C pathway which presents an opportunity for exfiltration of payload data or other spacecraft data depending on the interface and data exchange.