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A Practical Guide to Your System Security Plan (SSP) for CMMC/NIST 800-171 Compliance

Posted by: Kevin Hancock March 23, 2023 CMMC, Compliance
A Practical Guide to Your System Security Plan (SSP) for CMMC/NIST 800-171 Compliance

With the growing importance of cybersecurity in today’s world, businesses need to ensure that their information systems are adequately protected. The Cybersecurity Maturity Model Certification (CMMC) and NIST 800-171 are two key frameworks that help organizations protect sensitive data. Bookmark this blog as a practical guide to developing your System Security Plan (SSP) for CMMC/NIST 800-171 compliance. 

Understanding CMMC and NIST 800-171 

CMMC 2.0 is a unified cybersecurity standard for the Defense Industrial Base (DIB), focused on protecting controlled unclassified information (CUI) in non-federal systems. NIST 800-171, on the other hand, is a set of guidelines published by the National Institute of Standards and Technology, which provides recommended requirements to protect sensitive data and the confidentiality of CUI. 

When you’re ready to start developing your System Security Plan (SSP), follow the steps below to be sure you cover all the bases. 

What Is a System Security Plan?

A System Security Plan is a formal document that describes how your organization protects its information systems and data. Think of it as a blueprint for your cybersecurity program. It maps out your security controls, policies, and procedures in one comprehensive document. The SSP explains what security measures are in place, who is responsible for them, and how they are maintained.

For defense contractors, an SSP is particularly important because it demonstrates compliance with NIST 800-171 and CMMC requirements. It shows your customers and auditors that you understand security requirements and have implemented cybersecurity controls to protect CUI.

Who Needs an SSP?

You need a System Security Plan if your organization handles CUI as part of Department of Defense contracts. SSP requirements apply to both prime contractors and subcontractors in the defense industrial base who are working toward CMMC compliance.

You need an SSP if:

  • You have direct contracts with the DoD involving CUI
  • You are a subcontractor receiving CUI from prime contractors
  • Your company processes, stores, or transmits CUI
  • You plan to bid on future DoD contracts requiring CMMC certification

An SSP is not optional. It’s a mandatory requirement for demonstrating that your cybersecurity controls meet CMMC standards. Without a properly documented SSP, you cannot achieve CMMC certification, which may prevent you from winning or maintaining DoD contracts.

Even if you’re currently a small subcontractor who doesn’t directly handle CUI, you should consider developing an SSP if you plan to expand your defense business. Having an SSP in place demonstrates to prime contractors and government clients that you take seriously your responsibility to protect CUI and are committed to maintaining robust cybersecurity practices.

When you’re ready to start developing your System Security Plan, follow the SSP guidancesteps below to be sure you cover all the bases. 

1. Develop and Implement Your System Security Plan 

As you work on your SSP, keep the following questions in mind:  

  • Where is information entering our system? 
  • Where is the information stored — on-premises, cloud, backup/DR?  
  • What individuals interact with the data?  
  • How do they use the data  
  • How do they store, process, and transmit the data? 
  • Who supports the systems? 
  • Where are the users physically located? 

Identify and Categorize Information Systems 

The first step in developing your System Security Plan is identifying all information systems that process, store, or transmit CUI. You should categorize these systems according to their security requirements based on the CMMC level you aim to achieve and the sensitivity of the information they handle. 

Assess Your Current Security Controls 

Review your current security controls and assess them against the security requirements outlined in NIST 800-171. Identify any gaps and create a system security plan to address these areas of non-compliance. Remember that the CMMC framework is cumulative, meaning that each level includes the security requirements of the previous levels. 

With a clear understanding of the security requirements, develop your SSP by documenting all relevant security controls, policies, and procedures. Your SSP should include: 

  • An overview of your organization’s security policies 
  • A detailed description of your information systems and their environments 
  • A description of the security controls implemented in your systems 
  • A plan of action and milestones (POA&M) to address any identified security requirement gaps 

2. Conduct Regular Assessments of Your System Security Plan

Perform periodic assessments to ensure that your SSP remains up-to-date and reflects the current state of your information systems. Assessments can be performed internally or through third-party providers. The results should be documented in a Basic Assessment Report (BAR) and uploaded to the Supplier Performance Risk System (SPRS), as required by the Department of Defense (DoD). 

Train Your Workforce 

Your employees play a critical role in maintaining the security of your information systems. Provide regular training on best practices for cybersecurity solutions, and ensure your staff knows their responsibilities in protecting CUI. 

3. Maintain and Update Your SSP 

Your SSP should be a living document, regularly reviewed and updated to account for changes in your information systems or new threats. As your organization evolves, your SSP should evolve with it to maintain your CMMC 2.0 compliance. 

Your SSP should include, but not be limited to, the following elements:   

  • Data Flow Diagram 
  • Plan of Action & Milestones 
  • Asset Inventory 
  • Users 
  • Periodic Reviews 

Developing an SSP that meets the security requirements of CMMC/NIST 800-171 is a critical step for organizations looking to protect sensitive data and their valuable information while maintaining compliance with federal regulations. By following the SSP guidance outlined in this cybersecurity solutions guide, you can ensure that your organization is well-prepared to meet cybersecurity challenges and protect the sensitive data you handle.

Note About Third Parties 

When working with third parties, such as cloud service providers, Cloud Service Providers, keep in mind this text from DFARS 7012*: (D) If the Contractor intends to use an external cloud service provider to store, process, or transmit any covered defense information in performance of this contract, the Contractor shall require and ensure that the cloud service provider meets security requirements equivalent to those established by the Government for the Federal Risk and Authorization Program (FedRAMP) Moderate baseline and that the cloud service provider complies with requirements in paragraphs (c) through (g) of this clause for cyber incident reporting, malicious software, media preservation and protection, access to additional information and equipment necessary for forensic analysis, and cyber incident damage. 

Leverage our Expertise to Save Resources and Time 

We understand there’s a lot to consider and do when putting together and maintaining your SSP. Exostar cybersecurity solutions can help you achieve CMMC compliance and protect sensitive data and information. Ready to simplify your CMMC 2.0 compliance journey? Start your free trial of Exostar’s Policy Pro and Certification Assistant today and experience the difference for yourself. 

You’re invited to learn more in the on-demand webinar below.