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.

Sources

Best Segment for Countermeasure Deployment

  • Space Segment

NIST Rev5 Controls

D3FEND

ISO 27001

ID: CM0038
D3FEND Artifacts: 
Created: 2022/10/19
Last Modified: 2022/12/08

Techniques Addressed by Countermeasure

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ID Name Description
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.
.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.
.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-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.
.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.
.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.
.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.
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.
.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.
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 to laterally move to another area of the spacecraft.
LM-0004 Visiting Vehicle Interface(s) Threat actors may move from one spacecraft to another through visiting vehicle interfaces. When a vehicle docks with a spacecraft, many programs are automatically triggered in order to ensure docking mechanisms are locked. This entails several data points and commands being sent to and from the spacecraft and the visiting vehicle. If a threat actor were to compromise a visiting vehicle, they could target these specific programs in order to send malicious commands to the victim spacecraft once docked.
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.
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.

Space Threats Addressed by Countermeasure

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;