AC-6 - Least Privilege

Employ the principle of least privilege, allowing only authorized accesses for users (or processes acting on behalf of users) that are necessary to accomplish assigned organizational tasks.


Informational References

ISO 27001

ID: AC-6
Enhancements:  1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10

Countermeasures Covered by Control

ID Name Description D3FEND
CM0052 Insider Threat Protection Establish policy and procedures to prevent individuals (i.e., insiders) from masquerading as individuals with valid access to areas where commanding of the spacecraft is possible. Establish an Insider Threat Program to aid in the prevention of people with authorized access performing malicious activities.
CM0039 Least Privilege Employ the principle of least privilege, allowing only authorized processes which are necessary to accomplish assigned tasks in accordance with system functions. Ideally maintain a separate execution domain for each executing process.
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.
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.

Space Threats Tagged by Control

ID Description
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-MA-7 Exploit ground system and use to maliciously to interact with the spacecraft

Sample 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] should have requirements/controls for all ground/terrestrial systems covering: Data Protection, Ground Software, Endpoints, Networks, Computer Network Defense / Incident Response, Perimeter Security, Physical Controls, and Prevention Program (SSP, PPP, and Training).See NIST 800-53 and CNSSI 1253 for guidance on ground security {SV-MA-7}
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 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 enforce approved authorizations for controlling the flow of information within the platform and between interconnected systems so that information does not leave the platform boundary unless it is encrypted.{SV-AC-6}{AC-3(3),AC-3(4),AC-4,AC-4(6),AC-4(21),CA-3,CA-3(6),CA-3(7),CA-9,IA-9,SA-8(19),SC-8(1),SC-16(3)}
The [spacecraft] shall, when transferring information between different security domains, implements the following security policy filters that require fully enumerated formats that restrict data structure and content: connectors and semaphores implemented in the RTOS.{SV-AC-6}{AC-3(3),AC-3(4),AC-4(14),IA-9,SA-8(19),SC-16}
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] data within partitioned applications shall not be read or modified by other applications/partitions.{SV-AC-6}{AC-3(3),AC-3(4),SA-8(19),SC-2(2),SC-4,SC-6,SC-32}
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 [organization] shall state that information should not be allowed to flow between partitioned applications unless explicitly permitted by the Program's security policy.{SV-AC-6}{AC-4,AC-4(6)}
The [spacecraft] shall use protected processing domains to enforce the policy that information does not leave the platform boundary unless it is encrypted as a basis for flow control decisions.{SV-AC-6}{AC-4(2),IA-9,SA-8(19),SC-8(1),SC-16(3)}
The [organization] shall define the resources to be allocated to protect the availability of system resources.{SV-AC-6}{CP-2(2),SC-6}
The [spacecraft] shall prevent unauthorized and unintended information transfer via shared system resources.{SV-AC-6}{PM-32,SA-8(2),SA-8(5),SA-8(6),SA-8(19),SC-2(2),SC-4}
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] flight software must not be able to tamper with the security policy or its enforcement mechanisms.{SV-AC-6}{SA-8(16),SA-8(19),SC-3,SC-7(13)}
The [spacecraft] shall protect the availability of resources by allocating [organization]-defined resources based on [priority and/or quota].{SV-AC-6}{SC-6} In particular, this control is required for all space platform buses to ensure execution of high priority functions; it is particularly important when there are multiple payloads sharing a bus providing communications and other services, where bus resources must be prioritized based on mission.
The [organization] shall define the security safeguards to be employed to protect the availability of system resources.{SV-AC-6}{SC-6,SI-17}

Related SPARTA Techniques and Sub-Techniques

ID Name Description
REC-0001 Gather Spacecraft Design Information Threat actors may gather information about the victim SV's design that can be used for future campaigns or to help perpetuate other techniques. Information about the SV 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 SV'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 SV'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 SV'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 SV or any of its subsystems. Some SVs 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 SV.
REC-0001.04 Data Bus Threat actors may gather information about the data bus used within the victim SV 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 SV. 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 SV 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 SV 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 SV. 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 SV. 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 SV. 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 SV. This information can help threat actors construct specific attacks that may put the SV 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 SV'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 SV'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 SV'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 SV's designer/builder, including physical locations, key employees, and roles and responsibilities as they pertain to the SV, as well as information pertaining to the mission's end users/customers.
REC-0002.03 Operations Threat actors may gather information about the victim SV'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 SV'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 SV. 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 SV is 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 SV as it orbits the earth and determine how a satellite must be oriented in order to communicate with the victim SV. 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 SV. 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 SV. Valid Commanding Periods: This information can provide insight into when a command will be accepted by the SV and help the threat actor construct a viable attack campaign.
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 SV. 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 SV'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 SV 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 SV. Safe-mode is when all non-essential systems are shut down and only essential functions within the SV 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 SV 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 SV'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 space vehicle. Threat actors may find vulnerability information by searching leaked documents, vulnerability databases/scanners, compromising ground systems, and searching through online databases.
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 SV. 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 SV. By compromising this infrastructure, threat actors can stage, launch, and execute an operation.
RD-0003 Obtain Capabilities Threat actors may buy and/or steal 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 SV 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 SV.
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 SV, 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 SV, 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 SV 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. 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 SV.
IA-0005.02 Docked Vehicle / OSAM Threat actors may leverage docking vehicles to laterally move into a target SV. 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 SV via the docking interface.
IA-0005.03 Proximity Grappling Threat actors may posses the capability to grapple target SVs 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 SV, 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 SV 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 Station Threat actors may initially compromise the ground station in order to access the target SV. 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.
IA-0007.01 Compromise On-Orbit Update Threat actors may manipulate and modify on-orbit updates before they are sent to the target SV. 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 SV. 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 SV. 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 space vehicle. 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 space vehicle. Attackers may leverage security weaknesses in the vendor environment to gain access to more critical mission resources or network locations. In the space vehicle 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 space vehicles. It is no longer atypical to see space vehicles, 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 space vehicles by copying the malicious code to auxiliary/peripheral devices and taking advantage of logic on the space vehicle 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 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 SV. On-board resources within the SV 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-0009 Exploit Code Flaws Threats actors may identify and exploit flaws or weaknesses within the software running on-board the target SV. 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.
EX-0009.02 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.
EX-0009.03 Known Vulnerability (COTS/FOSS) Threat actors may utilize knowledge of the SV software composition to enumerate and exploit known flaws or vulnerabilities in the commercial or open source software running on-board the target SV.
EXF-0006 Modify 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-0007 Compromised Ground Station 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 SV. 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 SV 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 SV 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.
PER-0003 Ground System Presence Threat actors may compromise target owned ground systems that can be used for persistent access to the SV or to perpetuate other techniques. These ground systems have already been configured for communications to the victim SV. By compromising this infrastructure, threat actors can stage, launch, and execute persistently.
DE-0002 Prevent Downlink Threat actors may target the downlink connections to prevent the victim SV from sending telemetry to the ground controllers. Telemetry is the only method in which ground controllers can monitor the health and stability of the SV 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 SV 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 SV 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-0006 Modify Whitelist Threat actors may target whitelists on the space vehicles 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 space vehicles. 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 space vehicle that utilizes whitelisting.
LM-0001 Hosted Payload Threat actors may use the hosted payload within the victim SV 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 SVs on-board flat architecture for lateral movement purposes. Depending on implementation decisions, SVs 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 to laterally move to another area of the SV.
LM-0004 Visiting Vehicle Interface(s) Threat actors may move to other SVs through visiting vehicle interfaces. When a vehicle docks with a SV, 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 SV 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 SV once docked.