Customized Development of Critical Components
LOW MODERATE HIGHRequirements NIST SOURCE
Reimplement or custom develop the following critical system components: [critical system].
Discussion (NIST Supplemental Guidance)
Organizations determine that certain system components likely cannot be trusted due to specific threats to and vulnerabilities in those components for which there are no viable security controls to adequately mitigate risk. Reimplementation or custom development of such components may satisfy requirements for higher assurance and is carried out by initiating changes to system components (including hardware, software, and firmware) such that the standard attacks by adversaries are less likely to succeed. In situations where no alternative sourcing is available and organizations choose not to reimplement or custom develop critical system components, additional controls can be employed. Controls include enhanced auditing, restrictions on source code and system utility access, and protection from deletion of system and application files.
Implementation Guidance
Original engineering commentary written for this explorer — not NIST source text and not authoritative guidance.
No engineering interpretation has been authored for SA-20 yet. This section is architected to receive it — see the Requirements and Assessment sections above for the authoritative NIST source content in the meantime.
Assessment
Assessment Objectives
- critical system components to be reimplemented or custom-developed are defined;
- <SA-20_ODP critical system> are reimplemented or custom-developed.
Examine
[SELECT FROM: Supply chain risk management plan; system and services acquisition policy; procedures addressing the customized development of critical system components; system design documentation; system configuration settings and associated documentation; system development life cycle documentation addressing the custom development of critical system components; configuration management records; system audit records; system security plan; other relevant documents or records].
Interview
[SELECT FROM: Organizational personnel with system and service acquisition responsibilities; organizational personnel with information security responsibilities; organizational personnel with responsibility for the reimplementation or customized development of critical system components].
Test
[SELECT FROM: Organizational processes for the reimplementation or customized development of critical system components; mechanisms supporting and/or implementing the reimplementation or customized development of critical system components].
STIGs & CCIs
No STIG checks or CCI mappings are currently loaded for SA-20. This section is architected to display, per product: STIG ID, Finding ID, Severity, Title, Description, Check, Fix, CCI, and NIST control mapping — but nothing is populated here until a real DISA STIG/CCI dataset is ingested.
Learn more about STIG/CCI integration →Evidence
Categorized from the SP 800-53A "Examine"/"Test" artifact list above by keyword — not an authoritative NIST evidence list.
Policy
- Supply chain risk management plan
- system and services acquisition policy
- system security plan
Configuration
- system design documentation
- system configuration settings and associated documentation
- configuration management records
Testing
- Organizational processes for the reimplementation or customized development of critical system components
- mechanisms supporting and/or implementing the reimplementation or customized development of critical system components
Other Records
- procedures addressing the customized development of critical system components
- system development life cycle documentation addressing the custom development of critical system components
- system audit records
- other relevant documents or records