SC-24: Fail in Known State
Control Family:
Baselines:
- Low
N/A
- Moderate
N/A
- High
- SC-24
- Privacy
N/A
- OT Low (SP 800-82r3)
N/A
- OT Moderate (SP 800-82r3)
- SC-24
- OT High (SP 800-82r3)
- SC-24
Previous Version:
- NIST Special Publication 800-53 Revision 4:
- SC-24: Fail In Known State
Control Statement
Fail to a [Assignment: organization-defined known system state] for the following failures on the indicated components while preserving [Assignment: organization-defined system state information] in failure: [Assignment: organization-defined types of system failures on system components].
Supplemental Guidance
Failure in a known state addresses security concerns in accordance with the mission and business needs of organizations. Failure in a known state prevents the loss of confidentiality, integrity, or availability of information in the event of failures of organizational systems or system components. Failure in a known safe state helps to prevent systems from failing to a state that may cause injury to individuals or destruction to property. Preserving system state information facilitates system restart and return to the operational mode with less disruption of mission and business processes.
OT Discussion
The organization selects an appropriate failure state. Preserving OT state information includes consistency among OT state variables and the physical state that the OT represents (e.g., whether valves are open or closed, communication permitted or blocked, continue operations).
OT Baseline Rationale
Rationale for adding to Mod baseline: As part of the architecture and design of the OT, the organization selects an appropriate failure state in accordance with the function performed by the OT and the operational environment. The ability to choose the failure mode for the physical part of OT differentiates OT systems from other IT systems. This choice may be a significant influence in mitigating the impact of a failure since it may be disruptive to ongoing physical processes (e.g., valves failing in closed position may adversely affect system cooling).