Error Detection and Correcting Memory

Techniques Addressed by Countermeasure

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ID		Name	Description
EX-0007		Trigger Single Event Upset	Threat actors may utilize techniques to create a single-event upset (SEU) which is a change of state caused by one single ionizing particle (ions, electrons, photons...) striking a sensitive node in a spacecraft(i.e., microprocessor, semiconductor memory, or power transistors). The state change is a result of the free charge created by ionization in or close to an important node of a logic element (e.g. memory "bit"). This can cause unstable conditions on the spacecraft depending on which component experiences the SEU. SEU is a known phenomenon for spacecraft due to high radiation in space, but threat actors may attempt to utilize items like microwaves to create a SEU.

Space Threats Addressed by Countermeasure

ID	Description
SV-IT-4	Cause bit flip on memory via single event upsets
SV-AV-5	Using fault management system against you. Understanding the fault response could be leveraged to get satellite in vulnerable state. Example, safe mode with crypto bypass, orbit correction maneuvers, affecting integrity of TLM to cause action from ground, or some sort of RPO to cause S/C to go into safe mode;

Low-Level Requirements

Requirement	Rationale/Additional Guidance/Notes
The [organization] shall identify and properly classify mission sensitive design/operations information and access control shall be applied in accordance with classification guides and applicable federal laws, Executive Orders, directives, policies, regulations, and standards.{SV-CF-3,SV-AV-5}{AC-3,CM-12,CP-2,PM-17,RA-5(4),SA-3,SA-3(1),SA-5,SA-8(19),SC-8(1),SC-28(3),SI-12}	* Mission sensitive information should be classified as Controlled Unclassified Information (CUI) or formally known as Sensitive but Unclassified. Ideally these artifacts would be rated SECRET or higher and stored on classified networks. Mission sensitive information can typically include a wide range of candidate material: the functional and performance specifications, the RF ICDs, 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, SBU, 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.
The [organization] shall distribute documentation to only personnel with defined roles and a need to know.{SV-CF-3,SV-AV-5}{CM-12,CP-2,SA-5,SA-10}	Least privilege and need to know should be employed with the protection of all documentation. Documentation can contain sensitive information that can aid in vulnerability discovery, detection, and exploitation. For example, command dictionaries for ground and space systems should be handles with extreme care. Additionally, design documents for missions contain many key elements that if compromised could aid in an attacker successfully exploiting the system.
The [organization] shall protect documentation and Essential Elements of Information (EEI) as required, in accordance with the risk management strategy.{SV-CF-3,SV-AV-5}{SA-5}	Essential Elements of Information (EEI):
The [spacecraft] shall enter a cyber-safe mode when conditions that threaten the platform are detected, enters a cyber-safe mode of operation with restrictions as defined based on the cyber-safe mode.{SV-AV-5,SV-AV-6,SV-AV-7}{CP-10(6),CP-12,CP-13,IR-4,IR-4(1),IR-4(3),PE-10,RA-10,SA-8(16),SA-8(21),SA-8(24),SI-3,SI-4(7),SI-13,SI-17}
The [spacecraft] shall provide the capability to enter the platform into a known good, operational cyber-safe mode from a tamper-resistant, configuration-controlled (“gold”) image that is authenticated as coming from an acceptable supplier, and has its integrity verified.{SV-AV-5,SV-AV-6,SV-AV-7}{CP-10(6),CP-12,CP-13,IR-4(3),SA-8(16),SA-8(19),SA-8(21),SA-8(24),SI-13,SI-17}	Cyber-safe mode is an operating mode of a spacecraft during which all nonessential systems are shut down and the spacecraft is placed in a known good state using validated software and configuration settings. Within cyber-safe mode authentication and encryption should still be enabled. The spacecraft should be capable of reconstituting firmware and SW functions to preattack levels to allow for the recovery of functional capabilities. This can be performed by self-healing, or the healing can be aided from the ground. However, the spacecraft needs to have the capability to replan, based on available equipment still available after a cyberattack. The goal is for the vehicle to resume full mission operations. If not possible, a reduced level of mission capability should be achieved.
The [spacecraft] shall fail to a known secure state for failures during initialization, and aborts preserving information necessary to return to operations in failure.{SV-AV-5,SV-AV-6,SV-AV-7}{CP-10(6),CP-13,SA-8(16),SA-8(19),SA-8(24),SC-24,SI-13,SI-17}
The [spacecraft] shall provide or support the capability for recovery and reconstitution to a known state after a disruption, compromise, or failure.{SV-AV-5,SV-AV-6,SV-AV-7}{CP-4(4),CP-10,CP-10(4),CP-10(6),CP-13,IR-4,IR-4(1),SA-8(16),SA-8(19),SA-8(24)}
The [spacecraft] shall be designed and configured so that spacecraft memory can be monitored by the on-board intrusion detection/prevention capability.{SV-DCO-1}{RA-10,SA-8(21),SI-3,SI-3(10),SI-4,SI-4(1),SI-4(24),SI-16}
The [spacecraft] shall generate error messages that provide information necessary for corrective actions without revealing information that could be exploited by adversaries.{SV-AV-5,SV-AV-6,SV-AV-7}{RA-5(4),SI-4(12),SI-11}
The [spacecraft] shall reveal error messages only to operations personnel monitoring the telemetry.{SV-AV-5,SV-AV-6,SV-AV-7}{RA-5(4),SI-4(12),SI-11}
The [spacecraft] fault management solution shall utilize memory uncorrectable bit error detection information in a strategy to autonomously minimize the adverse effects of uncorrectable bit errors within the spacecraft.{SV-IT-4}{SI-16}
The [spacecraft] Interrupt Service Routine (ISR) shall have the ability to simultaneously update check-bits for [organization]-defined memory addresses.{SV-IT-4}{SI-16}
The [spacecraft] shall integrate EDAC scheme with fault management and cyber-protection mechanisms to respond to the detection of uncorrectable multi-bit errors, other than time-delayed monitoring of EDAC telemetry by the mission operators on the ground.{SV-IT-4}{SI-16}
The [spacecraft] shall use Error Detection and Correcting (EDAC) memory.{SV-IT-4}{SI-16}
The [spacecraft] shall utilize an EDAC scheme to routinely check for bit errors in the stored data on board the spacecraft, correct the single-bit errors, and identify the memory addresses of data with uncorrectable multi-bit errors of at least order two, if not higher order in some cases.{SV-IT-4}{SI-16}
The [spacecraft] cyber-safe mode software/configuration should be stored onboard the spacecraft in memory with hardware-based controls and should not be modifiable.{SV-AV-5,SV-AV-6,SV-AV-7}{SI-17}	Cyber-safe mode is using a fail-secure mentality where if there is a malfunction that the spacecraft goes into a fail-secure state where cyber protections like authentication and encryption are still employed (instead of bypassed) and the spacecraft can be restored by authorized commands. The cyber-safe mode should be stored in a high integrity location of the on-board SV so that it cannot be modified by attackers.
The [organization] shall ensure that FMEA/FMECA artifacts are strictly controlled so that particular fault responses are not disclosed via documentation.{SV-AV-5}