The Program shall ensure security requirements/configurations are placed on the development environments to prevent the compromise of source code from supply chain or information leakage perspective.
Low-Level Requirements
Requirement
Rationale/Additional Guidance/Notes
See threat IDs SV-SP-1,SV-SP-3,SV-SP-4, and SV-SP-10 for general supply chain protections. But any SW update should have two-man rule enacted. The spacecraft shall require multi-factor authorization for all SV [applications or operating systems] updates within the spacecraft. {SV-SP-9,SV-SP-11} {AC-3(2)}
Source code should be classified as Controlled Unclassified Information (CUI) or formally known as Sensitive but Unclassified. Ideally source code would be rated SECRET or higher and stored on classified networks. NIST 800-171 is insufficient when protecting highly sensitive unclassified information and more robust controls from NIST SP 800-53 and CNSSI 1253 should be employed. Greater scrutiny must be applied to all development environments.
This is not a cyber control for the spacecraft, but these controls would apply to ground system, contractor networks, etc. where design sensitive information would reside. NIST 800-171 is insufficient to properly protect this information from exposure, exfiltration, etc. See threat ID SV-SP-1, SV-SP-3, and SV-SP-4 for information on secure SW and supply chain protection. Should require contractors to be CMMC 2.0 Level 3 certified (https://www.acq.osd.mil/cmmc/about-us.html). The Program shall ensure [Program defined] security requirements/configurations are placed on the development environments to prevent the compromise of source code from supply chain or information leakage perspective. {SV-SP-10} {SA-15}
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.
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.
Threat actors may manipulate or compromise products or product delivery mechanisms before the customer receives them in order to achieve data or system compromise.
Threat actors may manipulate software dependencies (i.e. dependency confusion) and/or development tools prior to the customer receiving them in order to achieve data or system compromise. Software binaries and applications often depend on external software to function properly. spacecraft developers may use open source projects to help with their creation. These open source projects may be targeted by threat actors as a way to add malicious code to the victim spacecraft's dependencies.
Threat actors may manipulate software binaries and applications prior to the customer receiving them in order 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.
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.
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.
Organizations should look to identify and properly classify mission sensitive design/operations information (e.g., fault management approach) and apply access control accordingly. Any location (ground system, contractor networks, etc.) storing design information needs to ensure design info is protected from exposure, exfiltration, etc. Space system sensitive information may be classified as Controlled Unclassified Information (CUI) or Company Proprietary. Space system sensitive information can typically include a wide range of candidate material: the functional and performance specifications, any ICDs (like radio frequency, ground-to-space, etc.), command and telemetry databases, scripts, simulation and rehearsal results/reports, descriptions of uplink protection including any disabling/bypass features, failure/anomaly resolution, and any other sensitive information related to architecture, software, and flight/ground /mission operations. This could all need protection at the appropriate level (e.g., unclassified, CUI, proprietary, classified, etc.) to mitigate levels of cyber intrusions that may be conducted against the project’s networks. Stand-alone systems and/or separate database encryption may be needed with controlled access and on-going Configuration Management to ensure changes in command procedures and critical database areas are tracked, controlled, and fully tested to avoid loss of science or the entire mission. Sensitive documentation should only be accessed by personnel with defined roles and a need to know. Well established access controls (roles, encryption at rest and transit, etc.) and data loss prevention (DLP) technology are key countermeasures. The DLP should be configured for the specific data types in question.
A threat intelligence program helps an organization generate their own threat intelligence information and track trends to inform defensive priorities and mitigate risk. Leverage all-source intelligence services or commercial satellite imagery to identify and track adversary infrastructure development/acquisition. Countermeasures for this attack fall outside the scope of the mission in the majority of cases.
Use threat modeling, attack surface analysis, and vulnerability analysis to inform the current development process using analysis from similar systems, components, or services where applicable. Reduce attack surface where possible based on threats.
Conduct a criticality analysis to identify mission critical functions, critical components, and data flows and reduce the vulnerability of such functions and components through secure system design. Focus supply chain protection on the most critical components/functions. Leverage other countermeasures like segmentation and least privilege to protect the critical components.
Develop and implement anti-counterfeit policy and procedures designed to detect and prevent counterfeit components from entering the information system, including tamper resistance and protection against the introduction of malicious code or hardware.
Conduct a supplier review prior to entering into a contractual agreement with a contractor (or sub-contractor) to acquire systems, system components, or system services.
Components/Software that cannot be procured from the original component manufacturer or their authorized franchised distribution network should be approved by the supply chain board or equivalent to prevent and detect counterfeit and fraudulent parts, materials, and software.
Application-Specific Integrated Circuit (ASIC) / Field Programmable Gate Arrays should be developed by accredited trusted foundries to limit potential hardware-based trojan injections.
Perform physical inspection of hardware to look for potential tampering. Leverage tamper proof protection where possible when shipping/receiving equipment.
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.
Leverage best practices for crypto key management as defined by organization like NIST or the National Security Agency. Leverage only approved cryptographic algorithms, cryptographic key generation algorithms or key distribution techniques, authentication techniques, or evaluation criteria. Encryption key handling should be performed outside of the onboard software and protected using cryptography. Encryption keys should be restricted so that they cannot be read via any telecommands.
In order to secure the development environment, the first step is understanding all the devices and people who interact with it. Maintain an accurate inventory of all people and assets that touch the development environment. Ensure strong multi-factor authentication is used across the development environment, especially for code repositories, as threat actors may attempt to sneak malicious code into software that's being built without being detected. Use zero-trust access controls to the code repositories where possible. For example, ensure the main branches in repositories are protected from injecting malicious code. A secure development environment requires change management, privilege management, auditing and in-depth monitoring across the environment.
When using COTS or Open-Source, protect the version numbers being used as these numbers can be cross referenced against public repos to identify Common Vulnerability Exposures (CVEs) and exploits available.
Perform regular software updates to mitigate exploitation risk. Software updates may need to be scheduled around operational down times. Release updated versions of the software/firmware systems incorporating security-relevant updates, after suitable regression testing, at a frequency no greater than mission-defined frequency [i.e., 30 days]. Ideally old versions of software are removed after upgrading but restoration states (i.e., gold images) are recommended to remain on the system.
Vulnerability scanning is used to identify known software vulnerabilities (excluding custom-developed software - ex: COTS and Open-Source). Utilize scanning tools to identify vulnerabilities in dependencies and outdated software (i.e., software composition analysis). Ensure that vulnerability scanning tools and techniques are employed that facilitate interoperability among tools and automate parts of the vulnerability management process by using standards for: (1) Enumerating platforms, custom software flaws, and improper configurations; (2) Formatting checklists and test procedures; and (3) Measuring vulnerability impact.
Generate Software Bill of Materials (SBOM) against the entire software supply chain and cross correlate with known vulnerabilities (e.g., Common Vulnerabilities and Exposures) to mitigate known vulnerabilities. Protect the SBOM according to countermeasures in CM0001.
Ensure proper protections are in place for ensuring dependency confusion is mitigated like ensuring that internal dependencies be pulled from private repositories vice public repositories, ensuring that your CI/CD/development environment is secure as defined in CM0004 and validate dependency integrity by ensuring checksums match official packages.
Create prioritized list of software weakness classes (e.g., Common Weakness Enumerations), based on system-specific considerations, to be used during static code analysis for prioritization of static analysis results.
Define acceptable coding standards to be used by the software developer. The mission should have automated means to evaluate adherence to coding standards. The coding standard should include the acceptable software development language types as well. The language should consider the security requirements, scalability of the application, the complexity of the application, development budget, development time limit, application security, available resources, etc. The coding standard and language choice must ensure proper security constructs are in place.
Employ dynamic analysis (e.g., using simulation, penetration testing, fuzzing, etc.) to identify software/firmware weaknesses and vulnerabilities in developed and incorporated code (open source, commercial, or third-party developed code). Testing should occur (1) on potential system elements before acceptance; (2) as a realistic simulation of known adversary tactics, techniques, procedures (TTPs), and tools; and (3) throughout the lifecycle on physical and logical systems, elements, and processes. FLATSATs as well as digital twins can be used to perform the dynamic analysis depending on the TTPs being executed. Digital twins via instruction set simulation (i.e., emulation) can provide robust environment for dynamic analysis and TTP execution.
Perform static source code analysis for all available source code looking for system-relevant weaknesses (see CM0016) using no less than two static code analysis tools.
Prevent the installation of Flight Software without verification that the component has been digitally signed using a certificate that is recognized and approved by the mission.
Use automated mechanisms to maintain and validate baseline configuration to ensure the spacecraft's is up-to-date, complete, accurate, and readily available.
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.
Employ physical security controls (badge with pins, guards, gates, etc.) to prevent unauthorized access to the systems that have the ability to command the spacecraft.
Software/Firmware must verify a trust chain that extends through the hardware root of trust, boot loader, boot configuration file, and operating system image, in that order. The trusted boot/RoT computing module should be implemented on radiation tolerant burn-in (non-programmable) equipment.