NET-41: Cross Domain Solution (CDS)
Mechanisms exist to implement a Cross Domain Solution (CDS) to mitigate the specific security risks of accessing or transferring information between security domains.
Renumbered: Formerly NET-02.3 in SCF 2025.4.
Control Question: Does the organization implement a Cross Domain Solution (CDS) to mitigate the specific security risks of accessing or transferring information between security domains?
General (6)
| Framework | Mapping Values |
|---|---|
| MITRE ATT&CK 16 | T1021.001 T1021.003 T1021.006 T1046 T1048 T1048.001 T1048.002 T1072 T1098.001 T1133 T1136 T1136.002 T1190 T1199 T1210 T1482 T1489 T1552.007 T1557 T1557.001 T1557.003 T1557.004 T1563 T1563.002 T1565 T1565.003 T1622 |
| NIST 800-53 R5.2 | SC-46 |
| NIST 800-82 R3 | SC-46 |
| NIST 800-160 Vol2 R1 | SC-46 |
| NIST 800-207 | NIST Tenet 4 |
| SWIFT CSF 2025 | 2.4 |
US (3)
| Framework | Mapping Values |
|---|---|
| USA Federal CMMC 2.0 Level 3 | AC.L3-3.1.3E |
| USA Federal TSA SDP 2021-02F | III.C.5 |
| USA Federal TSA / DHS 1580/82-2022-01 | III.C.5 |
EMEA (1)
| Framework | Mapping Values |
|---|---|
| EMEA Saudi Arabia CSCC-1 2019 | 2-6-1-5 |
APAC (4)
| Framework | Mapping Values |
|---|---|
| APAC Australia CCM 2026 | PRO-09 |
| APAC Australia ISM June 2026 | ISM-0597 ISM-0610 ISM-0626 ISM-0635 ISM-0670 ISM-1287 ISM-1521 ISM-1522 ISM-1523 |
| APAC New Zealand NZISM 3.9 | 19.2.15.C.01 19.2.16.C.01 19.2.16.C.02 19.2.17.C.01 19.2.17.C.02 19.2.18.C.01 19.2.19.C.01 19.2.19.C.02 19.2.20.C.01 20.2.12.C.01 20.2.12.C.02 20.2.14.C.04 20.3.9.C.02 20.3.9.C.04 21.1.8.C.01 |
| APAC Singapore CCOP CII 2026 | 5.4.1 |
Capability Maturity Model
Level 0 — Not Performed
Practices are non-existent, based on the inability to demonstrate an implemented and operational capability. A reasonable person would conclude the control is not being performed.
Level 1 — Performed Informally
Network Security (NET) domain capabilities are ad hoc and inconsistent. Capability criteria associated with this control may include: ▪ Policies, standards & procedures associated with NET domain capabilities provide limited coverage due to the depth and breadth of the existing documentation. ▪ Network security-related activities are decentralized (e.g., a localized/regionalized function) and uses non-standardized methods to implement secure, resilient and compliant practices.
Level 2 — Planned & Tracked
Network Security (NET) capabilities are requirements-driven, but are not standardized across the entity (e.g., local/regional level consistency). Capability criteria associated with this control reasonably expect the following criteria to exist: ▪ Policies and standards associated with NET domain capabilities are formally documented and centrally-managed by the entity. ▪ Standardized Operating Procedures (SOP) associated with NET domain capabilities are documented and maintained by process owners. ▪ IT and/or cybersecurity personnel work with business stakeholders and process owners to appropriately scope and reasonably implement cybersecurity and data protection controls associated with NET domain capabilities to address applicable statutory, regulatory and/or contractual requirements for Technology Assets, Applications, Services and/or Data (TAASD). ▪ Network security-related controls are primarily administrative and preventative in nature (e.g., policies, standards and procedures & guidelines). ▪ Network security management may be a defined function (e.g., team or department) or assigned as an additional duty to existing IT and/or cybersecurity personnel. ▪ IT personnel define secure networking practices to protect the Confidentiality, Integrity, Availability and Safety (CIAS) of the organization's TAASD. ▪ Secure Baseline Configurations (SBC) enforce the principles of least privileges and least functionality for boundary protection technologies.
Level 3 — Well Defined
Network Security (NET) capabilities are standardized across the entity for applicability to People, Processes, Technologies, Data and/or Facilities (PPTDF) to ensure consistency for Technology Assets, Applications, Services and/or Data (TAASD). Capability criteria associated with this control reasonably expect the following criteria to exist: ▪ Policies and standards associated with NET domain capabilities are formally documented and centrally-managed by the entity's Governance, Risk & Compliance (GRC) team, or similar function. ▪ Standardized Operating Procedures (SOP) associated with NET domain capabilities are well-documented and kept current by process owners. ▪ A network security management team, or similar function, is appropriately staffed and supported to implement and maintain NET domain capabilities. ▪ Technology is leveraged to enhance the efficiency and accuracy of network security operations (e.g., network management solution and log aggregator). ▪ The entity's Governance, Risk & Compliance (GRC) team, or similar function, works with business stakeholders and process owners to appropriately scope and reasonably implement cybersecurity and data protection controls associated with NET domain capabilities to address Minimum Compliance Requirements (MCR) (e.g., applicable statutory, regulatory and/or contractual requirements) and Discretionary Security Requirements (DSR) (e.g., entity-required controls). ▪ Secure Baseline Configurations (SBC) enforce the principles of least privileges and least functionality for boundary protection technologies. ▪ An implemented and operational capability exists to implement a Cross Domain Solution (CDS) to mitigate the specific security risks of accessing or transferring information between security domains.
Level 4 — Quantitatively Controlled
Utilize SCR-CMM Level 3 criteria definitions: ▪ There are no defined Level 4 criteria, since it is reasonable to assume a quantitatively-controlled process is not necessary to operationalize this control. ▪ While it may be possible to develop “metrics-driven” capabilities for this control, the criteria would be organization-specific to define.
Level 5 — Continuously Improving
Utilize SCR-CMM Level 3 or Level 4 (if available) criteria definitions: ▪ There are no defined Level 5 criteria, since it is reasonable to assume a continuously-improving process is not necessary to operationalize this control. ▪ Level 5 capabilities should be considered “world-class” where the control builds on Level 4 capabilities, but are continuously improving through Artificial Intelligence (AI) and/or Machine Learning (ML) technologies. ▪ While it may be possible to develop responsive capabilities for this control through the use of AI and/or ML technologies, the criteria would be organization-specific to define.
Assessment Objectives
- NET-41_A01 a Cross Domain Solution (CDS) is implemented to mitigate the specific security risks of accessing or transferring information between security domains.
Technology Recommendations
Micro/Small
- Note: Typically not required at this size
Small
- Note: Typically not required at this size; document any data transfers between networks of different sensitivity
Medium
- Documented cross-domain solution policy
- Review data transfers between security domains
Large
- Formal cross-domain solution (CDS) controls
- Data transfer approval process
Enterprise
- Enterprise CDS platform
- Hardware data diodes where applicable
- Formal CDS approval and monitoring program