Require that the integrity of the following user-installed software be verified prior to execution: [Assignment: organization-defined user-installed software].
| ID | Name | Description | D3FEND | |
| CM0021 | Software Digital Signature | 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. | ||
| ID | Description | |
| Requirement | Rationale/Additional Guidance/Notes |
|---|---|
| The [organization] shall test software and firmware updates related to flaw remediation for effectiveness and potential side effects on mission systems in a separate test environment before installation.{SV-SP-1,SV-SP-3,SV-SP-6,SV-SP-7,SV-SP-9,SV-SP-11}{CM-3,CM-3(1),CM-3(2),CM-4(1),CM-4(2),CM-10(1),SA-8(31),SA-11(9),SI-2,SI-3,SI-3(10),SI-7(10),SI-7(12),SR-5(2)} | This requirement is focused on software and firmware flaws. If hardware flaw remediation is required, refine the requirement to make this clear. |
| The [organization] shall develop and document spacecraft integrity policies covering both hardware and software. {CM-5(6),SA-10(3),SI-1,SI-7(12)} | |
| The [organization] shall enable integrity verification of software and firmware components.{SV-IT-2}{CM-3(5),CM-5(6),CM-10(1),SA-8(9),SA-8(11),SA-8(21),SA-10(1),SI-3,SI-4(24),SI-7,SI-7(10),SI-7(12),SR-4(4)} | * The integrity verification mechanisms may include: ** Stipulating and monitoring logical delivery of products and services, requiring downloading from approved, verification-enhanced sites; ** Encrypting elements (software, software patches, etc.) and supply chain process data in transit (motion) and at rest throughout delivery; ** Requiring suppliers to provide their elements “secure by default”, so that additional configuration is required to make the element insecure; ** Implementing software designs using programming languages and tools that reduce the likelihood of weaknesses; ** Implementing cryptographic hash verification; and ** Establishing performance and sub-element baseline for the system and system elements to help detect unauthorized tampering/modification during repairs/refurbishing. ** Stipulating and monitoring logical delivery of products and services, requiring downloading from approved, verification-enhanced sites; ** Encrypting elements (software, software patches, etc.) and supply chain process data in transit (motion) and at rest throughout delivery; ** Requiring suppliers to provide their elements “secure by default”, so that additional configuration is required to make the element insecure; ** Implementing software designs using programming languages and tools that reduce the likelihood of weaknesses; ** Implementing cryptographic hash verification; and ** Establishing performance and sub-element baseline for the system and system elements to help detect unauthorized tampering/modification during repairs/refurbishing. |
| The [spacecraft] shall require multi-factor authorization for all spacecraft [applications or operating systems] updates within the spacecraft.{SV-SP-9,SV-SP-11}{AC-3(2),CM-3(8),CM-5,PM-12,SA-8(8),SA-8(31),SA-10(2),SI-3(8),SI-7(12),SI-10(6)} | The intent is for multiple checks to be performed prior to executing these SV SW updates. One action is mere act of uploading the SW to the spacecraft. Another action could be check of digital signature (ideal but not explicitly required) or hash or CRC or a checksum. Crypto boxes provide another level of authentication for all commands, including SW updates but ideally there is another factor outside of crypto to protect against FSW updates. Multi-factor authorization could be the "two-man rule" where procedures are in place to prevent a successful attack by a single actor (note: development activities that are subsequently subject to review or verification activities may already require collaborating attackers such that a "two-man rule" is not appropriate). |
| 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)} | |
| All [spacecraft] commands which have unrecoverable consequence must have dual authentication prior to command execution.{AU-9(5),IA-3,IA-4,IA-10,PE-3,PM-12,SA-8(15),SA-8(21),SC-16(2),SC-16(3),SI-3(8),SI-3(9),SI-4(13),SI-4(25),SI-7(12),SI-10(6),SI-13} | |
| The [spacecraft] shall have a method to ensure the integrity of these commands and validate their authenticity before execution.{AU-9(5),IA-3,IA-4,IA-10,PE-3,PM-12,SA-8(15),SA-8(21),SC-16(2),SC-16(3),SI-3(8),SI-3(9),SI-4(13),SI-4(25),SI-7(12),SI-10(6),SI-13} | |
| The [spacecraft] shall 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 ground.{SV-SP-1,SV-SP-3,SV-SP-6,SV-SP-9}{CM-3,CM-3(8),CM-5,CM-5(3),CM-14,SA-8(8),SA-8(31),SA-10(2),SI-3,SI-7(12),SI-7(15)} | |
| The [spacecraft] shall execute procedures for ensuring that security-relevant hardware, software, and firmware updates uploaded are exactly as specified by the gold copies. {CM-3(5),SA-8(8),SA-8(21),SA-8(31),SA-10(3),SA-10(4),SA-10(6),SI-7(10),SI-7(12)} | |
| The [spacecraft] shall perform an integrity check of software, firmware, and information at startup or during security-relevant events. {CM-3(5),SA-8(9),SA-8(11),SA-8(21),SI-3,SI-7(1),SI-7(10),SI-7(12),SI-7(17)} |
| ID | Name | Description | |
|---|---|---|---|
| IA-0001 | Compromise Supply Chain | Threat actors may manipulate or compromise products or product delivery mechanisms before the customer receives them in order to achieve data or system compromise. | |
| IA-0001.02 | Software Supply Chain | 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. | |
| 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-0004.02 | Receiver | Threat actors may target the backup/secondary receiver on the space vehicle as a method to inject malicious communications into the mission. The secondary receivers may come from different supply chains than the primary which could have different level of security and weaknesses. Similar to the ground station, the communication through the secondary receiver could be forced or happening naturally. | |
| 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. | |
| EX-0003 | Modify Authentication Process | Threat actors may modify the internal authentication process of the victim spacecraft to facilitate initial access, recurring execution, or prevent authorized entities from accessing the spacecraft. This can be done through the modification of the software binaries or memory manipulation techniques. | |
| EX-0004 | Compromise Boot Memory | Threat actors may manipulate boot memory in order to execute malicious code, bypass internal processes, or DoS the system. This technique can be used to perform other tactics such as Defense Evasion. | |
| PER-0001 | Memory Compromise | Threat actors may manipulate memory (boot, RAM, etc.) in order for their malicious code and/or commands to remain on the victim spacecraft. The spacecraft may have mechanisms that allow for the automatic running of programs on system reboot, entering or returning to/from safe mode, or during specific events. Threat actors may target these specific memory locations in order to store their malicious code or file, ensuring that the attack remains on the system even after a reset. | |
| PER-0002 | Backdoor | Threat actors may find and target various backdoors, or inject their own, within the victim spacecraft in the hopes of maintaining their attack. | |
| PER-0002.02 | Software | Threat actors may inject code to create their own backdoor to establish persistent access to the spacecraft. This may be done through modification of code throughout the software supply chain or through modification of the software-defined radio configuration (if applicable). | |
| DE-0007 | Rootkit | Rootkits are programs that hide the existence of malware by intercepting/hooking and modifying operating system API calls that supply system information. Rootkits or rootkit enabling functionality may reside at the flight software or kernel level in the operating system or lower, to include a hypervisor, Master Boot Record, or System Firmware. | |
| DE-0008 | Bootkit | Adversaries may use bootkits to persist on systems and evade detection. Bootkits reside at a layer below the operating system and may make it difficult to perform full remediation unless an organization suspects one was used and can act accordingly. | |
| 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. | |