CM0001 Protect Sensitive Information Space mission sensitive information spans a broad attack surface and must be inventoried, classified, and protected at a level commensurate with its sensitivity across every location where it resides, including ground systems, contractor networks, and remote access environments. Sensitive material typically includes functional and performance specifications, interface control documents (ICDs), command and telemetry (C&T) databases, uplink protection schemes including disable and bypass features, fault management logic, scripts, simulation and rehearsal results, failure and anomaly resolution records, and architecture and software documentation. Each information type must be assigned a protection level, such as unclassified, controlled, proprietary, or classified, and access must be restricted to personnel with defined roles and a verified need to know. Sensitive data shall be protected at rest and in transit using encryption or other mission-approved safeguards commensurate with its classification, sensitivity, threat exposure, and operational constraints. DLP capabilities shall be applied to systems and data flows where they are technically feasible and effective, with alternative access controls, monitoring, or information-flow protections used where conventional DLP technology is not suitable. Ongoing configuration management must track, control, and document all changes to command procedures and critical database content to prevent unauthorized modification and mission degradation.
CM0008 Security Testing Results Penetration testing, vulnerability scanning, fuzzing, code analysis, adversarial testing, and other security assessment activities are essential for validating the security posture of space systems. However, the artifacts generated by these activities are themselves sensitive mission information requiring protection. Security testing artifacts may include final reports, raw scanner output, working notes, exploit code, proof-of-concept scripts, packet captures, RF recordings, screenshots, logs, memory or core dumps, test credentials, command sequences, telemetry mappings, architecture diagrams, test configurations, remediation records, and copies of software or data collected during testing.
Security testing artifacts may reveal exploitable weaknesses, attack paths, security-control gaps, spacecraft and ground-system interfaces, command and telemetry behavior, link characteristics, safety interlocks, test accounts, and system-specific vulnerability conditions. Detailed evidence identifying an exploitable weakness, affected interface, and validated attack method may provide an adversary with much of the information needed to reproduce an attack.
Security testing results shall be categorized, marked, handled, stored, transmitted, shared, retained, and disposed of according to their information classification, CUI category, proprietary restrictions, contractual requirements, and mission sensitivity. Protection shall address both unauthorized disclosure and unauthorized modification, because alteration or deletion of test results could conceal vulnerabilities, misrepresent remediation status, or undermine security decisions. Access shall be limited by role and need to know throughout the artifact lifecycle, beginning when the data is generated and continuing through authorized disposition.
CM0020 Threat modeling Threat modeling is a structured analytical process that identifies, enumerates, and prioritizes potential threats to a system by systematically examining assets, trust boundaries, data flows, and adversary capabilities relative to the system's architecture. Applied in combination with attack surface analysis and vulnerability analysis, threat modeling produces an integrated picture of where the system is most exposed and what the consequences of successful exploitation would be. Analysis should draw on findings from similar systems, components, or services where applicable, leveraging documented threat experience from comparable missions or architectures to avoid re-learning known lessons. The outputs of threat modeling must directly inform design decisions throughout the development process, with attack surface reduction treated as a design objective rather than a post-development hardening activity: interfaces, services, protocols, and code paths that are not necessary to mission function should be eliminated or constrained before they become embedded in the architecture. Threat model artifacts should be treated as living documents, updated as the system design evolves and as new threat intelligence becomes available.
CM0022 Criticality Analysis Criticality analysis is a structured engineering process that identifies the mission functions, system components, and data flows whose compromise, degradation, or loss would most severely impact mission success, crew safety, or operational continuity. The outputs of this analysis directly drive security investment prioritization: components and functions assessed as most critical receive the most rigorous design-phase protections, supply chain scrutiny, and operational security controls, while lower-criticality elements are protected proportionately. Criticality analysis findings should inform the application of complementary security design principles, including network and functional segmentation and least-privilege access control, to isolate critical components from less-trusted system elements and reduce the consequence of compromise elsewhere in the system. Supply chain protection resources and oversight rigor should be explicitly allocated in proportion to component criticality, ensuring that the most mission-essential hardware and software receive the most intensive sourcing controls, provenance verification, and supplier oversight. Criticality analysis must be initiated early in the system design process and updated as the architecture evolves, threat intelligence changes, or operational experience reveals previously unrecognized dependencies.
CM0004 Development Environment Security A secure development environment requires a current and sufficiently complete inventory of the people, devices, software, services, credentials, and automated identities capable of accessing or influencing the environment. The development environment includes source-code repositories, developer workstations, build servers, CI/CD runners, compiler and linker toolchains, container and virtual machine images, package registries, artifact repositories, signing systems, test environments, integration laboratories, and release-staging systems.
For space systems, these environments may produce or manage flight software images, firmware, FPGA bitstreams, software-defined radio waveforms, command and telemetry databases, configuration tables, ephemerides, calibration products, fault-management logic, and on-orbit update packages. Unmanaged assets, unauthorized access, compromised dependencies, altered toolchains, and untrusted build services are significant pathways through which adversaries may maliciously modify software or other mission artifacts during development and build activities.
All personnel and assets touching the development environment must be inventoried and actively managed. MFA shall be enforced for human access, while non-human identities shall use managed workload identities, scoped credentials, protected secrets, and defined rotation or expiration period, with particular rigor applied to code repositories, where threat actors may attempt to inject malicious code into software under development without detection. Zero-trust access controls should govern repository access, with protected branch and tag policies shall restrict direct modification, prohibit unauthorized force pushes or deletion, require successful security checks, and require independent review before merging or releasing critical code. Effective development environment security also requires integrated change management, privilege management, comprehensive audit logging, and continuous in-depth monitoring across all components of the environment.
CM0011 Vulnerability Scanning Vulnerability scanning systematically identifies known security weaknesses in commercial off-the-shelf (COTS) and open-source software (OSS) components, including vulnerable dependencies and outdated software versions, across spacecraft and ground system environments. Custom-developed code requires separate analysis approaches, such as static and dynamic code analysis, that fall outside the scope of this countermeasure; however, COTS, OSS, and third-party dependencies incorporated into custom-developed software remain within the scope of vulnerability scanning and SCA. Scanning programs should incorporate software composition analysis (SCA) to detect vulnerabilities introduced through third-party libraries and dependency chains, which represent a significant and frequently underestimated attack surface in modern space systems. Scanning tools and processes should conform to recognized interoperability standards that support enumeration of platforms, software flaws, and configuration weaknesses; standardized formatting of checklists and test procedures; and consistent measurement of vulnerability impact. Adherence to these standards enables automation of key vulnerability management workflow steps, facilitates tool interoperability across the mission ecosystem, and produces outputs that are comparable across programs and organizations.
Vulnerability scanning shall be performed against the approved as-built or deployed software baseline using methods that do not jeopardize mission operations. Active scanning of live spacecraft, safety-critical ground systems, or operational technology should occur only after the scanning method has been authorized and evaluated for operational impact. Where live scanning presents unacceptable risk, scanning should be performed against representative software images, firmware packages, or test environments that match the approved operational baseline.
CM0012 Software Bill of Materials A software bill of materials (SBOM) is a structured inventory of software components, libraries, dependencies, and associated metadata comprising a delivered system, spanning first-party code and available third-party and open-source supply-chain information. The SBOM serves as the foundational reference for continuous vulnerability management: by cross-correlating the component inventory against known vulnerability databases, such as those cataloging common vulnerabilities and exposures (CVEs), mission owners and operators can rapidly identify which specific system components are affected by newly disclosed vulnerabilities and prioritize remediation accordingly. SBOM generation must cover the full software supply chain, including transitive dependencies that are not explicitly declared in top-level manifests, as these indirect inclusions represent a persistent and frequently exploited blind spot in software inventory programs. An SBOM may reveal component composition and vulnerability-relevant information that could assist adversary reconnaissance. Its classification, sensitivity, dissemination, and handling requirements shall be determined using applicable mission guidance, contractual requirements, and a documented disclosure-risk assessment. If deemed to have sensitive information then the handling controls applied should align to other mission-critical security documentation as defined in CM0001.
CM0016 CWE List A prioritized list of software weakness classes, drawn from a recognized weakness enumeration taxonomy such as the common weakness enumeration (CWE) framework, provides the analytical foundation for targeted, mission-relevant static code analysis. Rather than treating all weakness classes as equally significant, mission teams should derive a system-specific priority ranking based on the spacecraft or ground system's architecture, threat environment, operational constraints, and consequence of exploitation for each weakness class. This prioritized list serves two functions: it directs static analysis tool configuration toward the weakness classes most relevant to the mission, and it provides a defensible, documented basis for triaging and ranking analysis findings so that remediation resources are applied where mission risk is highest. The prioritization rationale should be documented and maintained as a controlled artifact, as it reflects security-relevant design decisions about the system's risk posture.
CM0017 Coding Standard A formally defined coding standard establishes the rules, conventions, and constraints that govern how software is written across the mission's development program, directly influencing the security, maintainability, and verifiability of the delivered system. The standard must specify acceptable programming language types, with language selection driven by a documented evaluation of security requirements, application complexity, scalability needs, available development resources, schedule constraints, and the availability of security-relevant language features such as memory safety, type safety, and bounds checking. Language choices that introduce classes of vulnerability by design, such as languages without memory safety guarantees used in contexts where memory corruption is a plausible attack vector, require explicit justification and compensating controls. The coding standard must include security-relevant rules for input validation, error handling, cryptographic usage, memory management, and concurrency, as applicable to the selected languages and system design. Adherence should be evaluated through automated means where supported, supplemented by manual review for requirements that cannot be reliably automated.
CM0047 Operating System Security The spacecraft operating system (OS) must be subjected to software assurance scrutiny commensurate with its mission criticality and security role. Prior assurance and flight-history evidence may be reused only after its applicability to the selected OS version, configuration, target hardware, operational use, and current mission security requirements has been evaluated. The OS must be analyzed for its attack surface, and all features, services, libraries, and interfaces not required for the mission's defined operational functions must be stripped, disabled, or removed before the OS is integrated into the flight software stack. This hardening requirement is particularly significant for some real-time operating systems (RTOS), which commonly include networking stacks, file systems, shell interfaces, diagnostic services, and other general-purpose capabilities that are unnecessary for spacecraft operations but expand the exploitable attack surface available to an adversary. Only an organization-approved OS product, version, build, and configuration baseline may be used in the delivered spacecraft system. The approved baseline must be enforced through reproducible build controls, configuration management, component inventories, and automated verification where supported.
CM0072 Protocol Update / Refactoring Communication and data exchange protocols governing spacecraft, ground system, and inter-system interfaces may contain specification-level vulnerabilities that cannot be resolved through implementation hardening alone, requiring updates to or refactoring of the protocol itself to eliminate the underlying weakness. Protocol vulnerabilities may arise from design flaws in the original specification, from advances in adversarial capability that render previously adequate security assumptions insufficient, or from emerging threats such as quantum computing that threaten the cryptographic primitives upon which protocol security depends. Protocol update or refactoring encompasses the deliberate modification of the rules, formats, and procedures governing system communications to address known vulnerabilities, improve security properties, or maintain adequate protection against the evolving threat environment over the mission's operational lifetime. Because space system protocols are often tightly coupled to hardware interfaces, flight software implementations, and ground system processing pipelines, protocol changes carry significant integration risk and must be managed through rigorous engineering change processes; this complexity makes proactive protocol security assessment and planned update capability more cost-effective than reactive refactoring under operational urgency.