CA.L2-3.12.4 System Security Plan

Develop, document, and periodically update system security plans that describe system boundaries, system environments of operation, how security requirements are implemented, and the relationships with or connections to other systems.

Source: NIST SP 800-171 Rev 2 3.12.4

Discussion: System security plans relate security requirements to a set of security controls. System security plans also describe, at a high level, how the security controls meet those security requirements, but do not provide detailed, technical descriptions of the design or implementation of the controls. System security plans contain sufficient information to enable a design and implementation that is unambiguously compliant with the intent of the plans and subsequent determinations of risk if the plan is implemented as intended. Security plans need not be single documents; the plans can be a collection of various documents including documents that already exist. Effective security plans make extensive use of references to policies, procedures, and additional documents (e.g., design and implementation specifications) where more detailed information can be obtained. This reduces the documentation requirements associated with security programs and maintains security-related information in other established management/operational areas related to enterprise architecture, system development life cycle, systems engineering, and acquisition. Federal agencies may consider the submitted system security plans and plans of action as critical inputs to an overall risk management decision to process, store, or transmit CUI on a system hosted by a nonfederal organization and whether it is advisable to pursue an agreement or contract with the nonfederal organization. [SP 800-18] provides guidance on developing security plans. [NIST CUI] provides supplemental material for Special Publication 800-171 including templates for system security plans.

Assessment Objectives:

Determine if:

• [a] a system security plan is developed;
• [b] the system boundary is described and documented in the system security plan;
• [c] the system environment of operation is described and documented in the system security plan;
• [d] the security requirements identified and approved by the designated authority as non-applicable are identified;
• [e] the method of security requirement implementation is described and documented in the system security plan;
• [f] the relationship with or connection to other systems is described and documented in the system security plan;
• [g] the frequency to update the system security plan is defined; and
• [h] system security plan is updated with the defined frequency.

Examine: [SELECT FROM: Security planning policy; procedures addressing security plan development and implementation; procedures addressing security plan reviews and updates; enterprise architecture documentation; security plan; records of security plan reviews and updates; other relevant documents or records].

Interview: [SELECT FROM: Personnel with security planning and plan implementation responsibilities; personnel with information security responsibilities].

Test: [SELECT FROM: Organizational processes for security plan development, review, update, and approval; mechanisms supporting the security plan].

SPRS Score: N/A

POA&M Allowed: Yes