Security Assessment

The Security Assessment family in NIST 800-171 Rev 2 focuses on ensuring that organizations regularly evaluate and improve their information system security controls and practices to protect Controlled Unclassified Information (CUI). The purpose of this family is to establish a formal process for assessing security controls, conducting regular system reviews, and ensuring continuous monitoring to identify and address potential vulnerabilities or weaknesses in security.

Key Security Assessment Requirements in NIST 800-171 Rev 2:

The Security Assessment family contains three security requirements that emphasize the need to assess and monitor the security posture of an organization’s systems, ensuring compliance with security requirements and continuous improvement of security measures.

1. Develop, Document, and Assess Security Controls (3.12.1)

Basic Requirement: Organizations must develop, document, and assess the security controls employed within their information systems to determine their effectiveness and ensure they meet the required standards for protecting CUI.

Key Focus:

Create and maintain a security assessment plan that outlines the procedures for evaluating the effectiveness of security controls.

Regularly assess whether security controls (e.g., access control, encryption, monitoring) are functioning as intended and are sufficient to protect CUI.

Document the results of security assessments to ensure that the organization can identify weaknesses and take corrective actions.

Example: Conducting an annual review of all security controls, such as firewalls, encryption methods, and access control systems, to ensure they are aligned with the latest security requirements and threats.

2. Develop and Implement Plans of Action (3.12.2)

Basic Requirement: Organizations must develop and implement plans of action designed to address weaknesses or deficiencies identified during security assessments or through continuous monitoring efforts.

Key Focus:

After identifying vulnerabilities or weaknesses, develop actionable plans to mitigate risks, implement security patches, or make configuration changes to strengthen the security posture.

The plan of action should include timelines for completing remediation and assigning responsibilities for addressing each issue.

Continuously update and track progress on the action plans to ensure that identified weaknesses are addressed in a timely manner.

Example: After a security assessment reveals a vulnerability in an outdated software version, developing a plan to upgrade the software and applying necessary security patches within 30 days.

3. Monitor Security Controls on an Ongoing Basis (3.12.3)

Basic Requirement: Organizations must monitor their security controls on an ongoing basis to ensure they continue to be effective and to detect and respond to any changes that could impact system security.

Key Focus:

Implement continuous monitoring of security controls, including real-time monitoring tools, periodic audits, and reviews to assess the ongoing effectiveness of controls.

Continuously track and respond to changes in the organization’s environment, such as new threats, configuration changes, or software updates, that may impact security controls.

Ensure that continuous monitoring provides visibility into potential security issues and ensures timely detection and response to any new vulnerabilities.

Example: Using a Security Information and Event Management (SIEM) system to continuously monitor network traffic for anomalies and potential security incidents.

Importance of Security Assessment in Cybersecurity:

Ensures Compliance: Regular security assessments help ensure that the organization complies with security requirements like those outlined in NIST 800-171 and other regulations governing the protection of CUI. This helps prevent non-compliance issues, which could result in fines or loss of business.

Identifies Vulnerabilities Early: By regularly assessing security controls, organizations can identify and address vulnerabilities before they are exploited by attackers. This proactive approach helps reduce the likelihood of data breaches or other security incidents.

Improves Security Posture: Ongoing security assessments and continuous monitoring ensure that the organization’s security posture remains strong and adaptive to new threats. This allows organizations to keep pace with evolving cybersecurity challenges and address weaknesses as they arise.

Supports Risk Management: Security assessments provide critical information needed for effective risk management. By identifying risks, assessing their potential impact, and developing action plans to mitigate them, organizations can manage security risks more effectively.

Enables Continuous Improvement: Regular assessments provide opportunities for continuous improvement in security practices. By evaluating the effectiveness of existing controls, organizations can fine-tune their security measures and improve their defenses over time.

Best Practices for Security Assessments:

Develop a Security Assessment Plan: Create a detailed plan that defines how and when security assessments will be conducted, including the scope, frequency, and methodology for evaluating security controls.

Conduct Regular Audits and Reviews: Perform periodic audits of security controls, such as quarterly or annual reviews, to evaluate whether the controls are still effective in protecting CUI and meeting security requirements.

Use Automated Monitoring Tools: Leverage automated tools like SIEM systems, vulnerability scanners, and intrusion detection/prevention systems (IDS/IPS) to continuously monitor security controls and detect potential weaknesses in real-time.

Respond Quickly to Identified Weaknesses: When vulnerabilities or deficiencies are identified during assessments or monitoring, take swift action to mitigate the risks. Develop a plan of action with clear deadlines and assign responsibility for remediation.

Maintain Documentation: Keep comprehensive records of all security assessments, findings, and corrective actions. This documentation is essential for tracking progress, demonstrating compliance, and conducting post-incident reviews.

Incorporate Lessons Learned: After security incidents or assessments, review the results and incorporate lessons learned into the security program. Update security policies, controls, and procedures to reflect these improvements.

Coordinate Assessments with Other Security Functions: Align security assessments with other cybersecurity functions such as incident response, vulnerability management, and risk assessments to provide a comprehensive view of the organization’s security posture.

Phases of Security Assessment:

Planning: Develop a security assessment plan that includes the objectives, scope, and methodology for assessing security controls. Identify the systems, controls, and processes to be evaluated.

Execution: Perform the security assessment, using tools such as vulnerability scanners, penetration testing, or manual reviews of controls. Collect and analyze data to identify any weaknesses or gaps.

Analysis: Analyze the findings from the assessment to determine the effectiveness of security controls and identify any areas where improvements are needed.

Reporting: Document the results of the assessment, including any vulnerabilities, deficiencies, or security gaps that were identified. Provide recommendations for addressing the issues.

Remediation: Develop and implement plans of action to address the identified weaknesses. This may involve applying security patches, changing configurations, updating software, or implementing additional security measures.

Continuous Monitoring: After the assessment, continuously monitor security controls to ensure they remain effective and to detect any new vulnerabilities or threats.

Summary:

The Security Assessment family in NIST 800-171 Rev 2 emphasizes the importance of regularly assessing, monitoring, and improving an organization’s security controls to protect Controlled Unclassified Information (CUI). By developing a formal assessment plan, addressing identified weaknesses with actionable plans, and continuously monitoring security controls, organizations can maintain a strong security posture, ensure compliance with regulatory requirements, and reduce the risk of data breaches or security incidents. Regular security assessments and continuous monitoring are key components of a proactive and resilient cybersecurity strategy.