SC: System and Communications Protection
OT Tailoring Considerations
The use of cryptography is determined after careful consideration of the security needs and the potential ramifications on system performance. For example, the organization considers whether latency induced from the use of cryptography would adversely impact the operational performance of the OT. While the legacy devices commonly found within OT often lack direct support for cryptographic functions, compensating controls (e.g., encapsulations) may be used to meet the intent of the control.
When the OT cannot support the specific system and communications protection requirements of a control, the organization employs compensating controls in accordance with the general tailoring guidance. Examples of compensating controls are given with each control as appropriate.
Controls
SC-1: Policy and Procedures
Baseline(s):
- Low
- Moderate
- High
- OT Low (SP 800-82r3)
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Develop, document, and disseminate to [Assignment: organization-defined personnel or roles]: [Assignment (one or more): organization-level, mission/business-process-level, system-level] system and communications protection policy that: Addresses purpose, scope, roles, responsibilities, management commitment, coordination among organizational entities, and compliance; and Is consistent with applicable laws, executive orders, directives, regulations, policies, standards, and guidelines; and Procedures to facilitate the…
SC-2: Separation of System and User Functionality
Baseline(s):
- Moderate
- High
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Separate user functionality, including user interface services, from system management functionality.
SC-3: Security Function Isolation
Baseline(s):
- High
- OT High (SP 800-82r3)
Isolate security functions from nonsecurity functions.
SC-4: Information in Shared System Resources
Baseline(s):
- Moderate
- High
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Prevent unauthorized and unintended information transfer via shared system resources.
SC-5: Denial-of-service Protection
Baseline(s):
- Low
- Moderate
- High
- OT Low (SP 800-82r3)
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
[Assignment: protect against, limit] the effects of the following types of denial-of-service events: [Assignment: organization-defined types of denial-of-service events] ; and Employ the following controls to achieve the denial-of-service objective: [Assignment: organization-defined controls by type of denial-of-service event].
SC-6: Resource Availability
Baseline(s):
Protect the availability of resources by allocating [Assignment: organization-defined resources] by [Assignment (one or more): priority, quota, [Assignment: organization-defined controls] ].
SC-7: Boundary Protection
Baseline(s):
- Low
- Moderate
- High
- OT Low (SP 800-82r3)
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Monitor and control communications at the external managed interfaces to the system and at key internal managed interfaces within the system; Implement subnetworks for publicly accessible system components that are [Assignment: physically, logically] separated from internal organizational networks; and Connect to external networks or systems only through managed interfaces consisting of boundary protection devices arranged…
SC-8: Transmission Confidentiality and Integrity
Baseline(s):
- Moderate
- High
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Protect the [Assignment (one or more): confidentiality, integrity] of transmitted information.
SC-10: Network Disconnect
Baseline(s):
- Moderate
- High
Terminate the network connection associated with a communications session at the end of the session or after [Assignment: organization-defined time period] of inactivity.
SC-11: Trusted Path
Baseline(s):
Provide a [Assignment: physically, logically] isolated trusted communications path for communications between the user and the trusted components of the system; and Permit users to invoke the trusted communications path for communications between the user and the following security functions of the system, including at a minimum, authentication and re-authentication: [Assignment: organization-defined security functions].
SC-12: Cryptographic Key Establishment and Management
Baseline(s):
- Low
- Moderate
- High
- OT Low (SP 800-82r3)
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Establish and manage cryptographic keys when cryptography is employed within the system in accordance with the following key management requirements: [Assignment: organization-defined requirements].
SC-13: Cryptographic Protection
Baseline(s):
- Low
- Moderate
- High
- OT Low (SP 800-82r3)
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Determine the [Assignment: organization-defined cryptographic uses] ; and Implement the following types of cryptography required for each specified cryptographic use: [Assignment: organization-defined types of cryptography].
SC-15: Collaborative Computing Devices and Applications
Baseline(s):
- Low
- Moderate
- High
- OT Low (SP 800-82r3)
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Prohibit remote activation of collaborative computing devices and applications with the following exceptions: [Assignment: organization-defined exceptions where remote activation is to be allowed] ; and Provide an explicit indication of use to users physically present at the devices.
SC-16: Transmission of Security and Privacy Attributes
Baseline(s):
Associate [Assignment: organization-defined security and privacy attributes] with information exchanged between systems and between system components.
SC-17: Public Key Infrastructure Certificates
Baseline(s):
- Moderate
- High
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Issue public key certificates under an [Assignment: organization-defined certificate policy] or obtain public key certificates from an approved service provider; and Include only approved trust anchors in trust stores or certificate stores managed by the organization.
SC-18: Mobile Code
Baseline(s):
- Moderate
- High
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Define acceptable and unacceptable mobile code and mobile code technologies; and Authorize, monitor, and control the use of mobile code within the system.
SC-20: Secure Name/Address Resolution Service (Authoritative Source)
Baseline(s):
- Low
- Moderate
- High
- OT Low (SP 800-82r3)
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Provide additional data origin authentication and integrity verification artifacts along with the authoritative name resolution data the system returns in response to external name/address resolution queries; and Provide the means to indicate the security status of child zones and (if the child supports secure resolution services) to enable verification of a chain of trust among…
SC-21: Secure Name/Address Resolution Service (Recursive or Caching Resolver)
Baseline(s):
- Low
- Moderate
- High
- OT Low (SP 800-82r3)
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Request and perform data origin authentication and data integrity verification on the name/address resolution responses the system receives from authoritative sources.
SC-22: Architecture and Provisioning for Name/Address Resolution Service
Baseline(s):
- Low
- Moderate
- High
- OT Low (SP 800-82r3)
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Ensure the systems that collectively provide name/address resolution service for an organization are fault-tolerant and implement internal and external role separation.
SC-23: Session Authenticity
Baseline(s):
- Moderate
- High
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Protect the authenticity of communications sessions.
SC-24: Fail in Known State
Baseline(s):
- High
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
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].
SC-25: Thin Nodes
Baseline(s):
Employ minimal functionality and information storage on the following system components: [Assignment: organization-defined system components].
SC-26: Decoys
Baseline(s):
Include components within organizational systems specifically designed to be the target of malicious attacks for detecting, deflecting, and analyzing such attacks.
SC-27: Platform-independent Applications
Baseline(s):
Include within organizational systems the following platform independent applications: [Assignment: organization-defined platform-independent applications].
SC-28: Protection of Information at Rest
Baseline(s):
- Moderate
- High
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Protect the [Assignment (one or more): confidentiality, integrity] of the following information at rest: [Assignment: organization-defined information at rest].
SC-29: Heterogeneity
Baseline(s):
Employ a diverse set of information technologies for the following system components in the implementation of the system: [Assignment: organization-defined system components].
SC-30: Concealment and Misdirection
Baseline(s):
Employ the following concealment and misdirection techniques for [Assignment: organization-defined systems] at [Assignment: organization-defined time periods] to confuse and mislead adversaries: [Assignment: organization-defined concealment and misdirection techniques].
SC-31: Covert Channel Analysis
Baseline(s):
Perform a covert channel analysis to identify those aspects of communications within the system that are potential avenues for covert [Assignment (one or more): storage, timing] channels; and Estimate the maximum bandwidth of those channels.
SC-32: System Partitioning
Baseline(s):
Partition the system into [Assignment: organization-defined system components] residing in separate [Assignment: physical, logical] domains or environments based on [Assignment: organization-defined circumstances for the physical or logical separation of components].
SC-34: Non-modifiable Executable Programs
Baseline(s):
For [Assignment: organization-defined system components] , load and execute: The operating environment from hardware-enforced, read-only media; and The following applications from hardware-enforced, read-only media: [Assignment: organization-defined applications].
SC-35: External Malicious Code Identification
Baseline(s):
Include system components that proactively seek to identify network-based malicious code or malicious websites.
SC-36: Distributed Processing and Storage
Baseline(s):
Distribute the following processing and storage components across multiple [Assignment: physical locations, logical domains]: [Assignment: organization-defined processing and storage components].
SC-37: Out-of-band Channels
Baseline(s):
Employ the following out-of-band channels for the physical delivery or electronic transmission of [Assignment: organization-defined information, system components, or devices] to [Assignment: organization-defined individuals or systems]: [Assignment: organization-defined out-of-band channels].
SC-38: Operations Security
Baseline(s):
Employ the following operations security controls to protect key organizational information throughout the system development life cycle: [Assignment: organization-defined operations security controls].
SC-39: Process Isolation
Baseline(s):
- Low
- Moderate
- High
- OT Low (SP 800-82r3)
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Maintain a separate execution domain for each executing system process.
SC-40: Wireless Link Protection
Baseline(s):
Protect external and internal [Assignment: organization-defined wireless links] from the following signal parameter attacks: [Assignment: organization-defined types of signal parameter attacks or references to sources for such attacks].
SC-41: Port and I/O Device Access
Baseline(s):
- OT Low (SP 800-82r3)
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
[Assignment: physically, logically] disable or remove [Assignment: organization-defined connection ports or input/output devices] on the following systems or system components: [Assignment: organization-defined systems or system components].
SC-42: Sensor Capability and Data
Baseline(s):
Prohibit [Assignment (one or more): the use of devices possessing [Assignment: organization-defined environmental sensing capabilities] in [Assignment: organization-defined facilities, areas, or systems] , the remote activation of environmental sensing capabilities on organizational systems or system components with the following exceptions: [Assignment: organization-defined exceptions where remote activation of sensors is allowed] ] ; and Provide an…
SC-43: Usage Restrictions
Baseline(s):
Establish usage restrictions and implementation guidelines for the following system components: [Assignment: organization-defined components] ; and Authorize, monitor, and control the use of such components within the system.
SC-44: Detonation Chambers
Baseline(s):
Employ a detonation chamber capability within [Assignment: organization-defined system, system component, or location].
SC-45: System Time Synchronization
Baseline(s):
- OT Low (SP 800-82r3)
- OT Moderate (SP 800-82r3)
- OT High (SP 800-82r3)
Synchronize system clocks within and between systems and system components.
SC-46: Cross Domain Policy Enforcement
Baseline(s):
Implement a policy enforcement mechanism [Assignment: physically, logically] between the physical and/or network interfaces for the connecting security domains.
SC-47: Alternate Communications Paths
Baseline(s):
- OT High (SP 800-82r3)
Establish [Assignment: organization-defined alternate communication paths] for system operations organizational command and control.
SC-48: Sensor Relocation
Baseline(s):
Relocate [Assignment: organization-defined sensors and monitoring capabilities] to [Assignment: organization-defined locations] under the following conditions or circumstances: [Assignment: organization-defined conditions or circumstances].
SC-49: Hardware-enforced Separation and Policy Enforcement
Baseline(s):
Implement hardware-enforced separation and policy enforcement mechanisms between [Assignment: organization-defined security domains].
SC-50: Software-enforced Separation and Policy Enforcement
Baseline(s):
Implement software-enforced separation and policy enforcement mechanisms between [Assignment: organization-defined security domains].
SC-51: Hardware-based Protection
Baseline(s):
Employ hardware-based, write-protect for [Assignment: organization-defined system firmware components] ; and Implement specific procedures for [Assignment: organization-defined authorized individuals] to manually disable hardware write-protect for firmware modifications and re-enable the write-protect prior to returning to operational mode.