NET-10.3: Sender Policy Framework (SPF)

There is no evidence of a capability to validate the legitimacy of email communications through configuring a Domain Naming Service (DNS) Sender Policy Framework (SPF) record to specify the IP addresses and/ or hostnames that are authorized to send email from the specified domain.

C|P-CMM1 is N/A, since a structured process is required to validate the legitimacy of email communications through configuring a Domain Naming Service (DNS) Sender Policy Framework (SPF) record to specify the IP addresses and/ or hostnames that are authorized to send email from the specified domain.

Network Security (NET) efforts are requirements-driven and governed at a local/regional level, but are not consistent across the organization. CMM Level 2 control maturity would reasonably expect all, or at least most, the following criteria to exist:

• Network security management is decentralized (e.g., a localized/regionalized function) and uses non-standardized methods to implement secure, resilient and compliant practices.
• IT/cybersecurity personnel identify cybersecurity and data protection controls that are appropriate to address applicable statutory, regulatory and contractual requirements for network security management.
• IT personnel define secure networking practices to protect the confidentiality, integrity, availability and safety of the organization's technology assets, data and network(s).
• Administrative processes and technologies focus on protecting High Value Assets (HVAs), including environments where sensitive/regulated data is stored, transmitted and processed.
• Administrative processes are used to configure boundary devices (e.g., firewalls, routers, etc.) to deny network traffic by default and allow network traffic by exception (e.g., deny all, permit by exception).
• Network segmentation exists to implement separate network addresses (e.g., different subnets) to connect systems in different security domains (e.g., sensitive/regulated data environments).

Network Security (NET) efforts are standardized across the organization and centrally managed, where technically feasible, to ensure consistency. CMM Level 3 control maturity would reasonably expect all, or at least most, the following criteria to exist:

• A Technology Infrastructure team, or similar function, defines centrally-managed network security controls for implementation across the enterprise.
• Secure engineering principles are used to design and implement network security controls (e.g., industry-recognized secure practices) to enforce the concepts of least privilege and least functionality at the network level.
• IT/cybersecurity architects work with the Technology Infrastructure team to implement a “layered defense” network architecture that provides a defense-in-depth approach for redundancy and risk reduction for network-based security controls, including wired and wireless networking.
• Administrative processes and technologies configure boundary devices (e.g., firewalls, routers, etc.) to deny network traffic by default and allow network traffic by exception (e.g., deny all, permit by exception).
• Technologies automate the Access Control Lists (ACLs) and similar rulesets review process to identify security issues and/ or misconfigurations.
• Network segmentation exists to implement separate network addresses (e.g., different subnets) to connect systems in different security domains (e.g., sensitive/regulated data environments).

See C|P-CMM3. There are no defined C|P-CMM4 criteria, since it is reasonable to assume a quantitatively-controlled process is not necessary to validate the legitimacy of email communications through configuring a Domain Naming Service (DNS) Sender Policy Framework (SPF) record to specify the IP addresses and/ or hostnames that are authorized to send email from the specified domain.

See C|P-CMM4. There are no defined C|P-CMM5 criteria, since it is reasonable to assume a continuously-improving process is not necessary to validate the legitimacy of email communications through configuring a Domain Naming Service (DNS) Sender Policy Framework (SPF) record to specify the IP addresses and/ or hostnames that are authorized to send email from the specified domain.