Conducting a cyber risk assessment for Federal Information Security Modernization Act (FISMA) compliance is a multi-step process that involves thorough planning, assessment, evaluation, and documentation of an information system’s security controls and inherent risks within a federal organization. Here’s a detailed guide on how to perform a cyber risk assessment to meet FISMA requirements.
Preliminary Preparations
Understanding FISMA Requirements
- Familiarize yourself with the FISMA legislation and the National Institute of Standards and Technology (NIST) guidelines, especially NIST SP 800-53 for security controls and SP 800-30 for risk assessment methodologies.
- Determine the FISMA categorization level of the information system (low, moderate, or high impact) based on the potential consequences of a security incident.
Assemble a Team of Experts
- Identify a cross-functional team that includes IT professionals, security experts, risk management personnel, and stakeholders.
- Designate a Chief Information Security Officer (CISO) or a similar role responsible for overseeing the risk assessment process.
Define the Scope of the Assessment
- Clearly describe the boundaries of the information system, including hardware, software, data, processes, and personnel involved.
- Include any third-party services or connections that may impact the system’s security posture.
Risk Assessment Process
Step 1: Risk Identification
- Inventory all information system assets and resources.
- Identify potential threats to the information system such as cyber-attacks, natural disasters, and human errors.
- Detect vulnerabilities within the system that could be exploited by threats.
Step 2: Threat and Vulnerability Analysis
- Use automated tools and manual methods to conduct vulnerability scans and security assessments.
- Consider using threat intelligence services to understand emerging cybersecurity threats.
- Assess the current security controls and their effectiveness in mitigating threats.
Step 3: Likelihood and Impact Determination
- Estimate the likelihood of potential threats exploiting system vulnerabilities.
- Assess the impact of potential incidents on the organization’s operations, assets, individuals, other organizations, and the nation.
Step 4: Control Analysis
- Review existing security controls and determine if they are appropriately implemented.
- Evaluate whether the controls are effective in reducing the risk to an acceptable level.
Step 5: Risk Determination
- By combining the results from the likelihood and impact assessment, categorize the levels of risk for each threat and vulnerability pair.
- Identify the risk appetite and tolerance levels set by the organization to aid in prioritization.
Risk Treatment and Documentation
Selecting Risk Responses
- For each identified risk, decide on a response: mitigate, accept, transfer, or avoid.
- For mitigation, select and recommend additional security controls or enhancements to existing controls.
Creating the System Security Plan (SSP)
- Document the assessment findings and the chosen security controls in the SSP.
- Update the SSP to include strategies for continuous monitoring and how the system addresses the identified risks.
Plan of Action and Milestones (POA&M)
- Develop a POA&M that outlines tasks to address deficiencies in the information system’s security controls.
- Include resources required, assigned responsibilities, and target completion dates for each task.
Final Steps
Review and Approval
- Submit the SSP, risk assessment report, and POA&M to the designated authorizing official (AO).
- The AO reviews the documents, making the final decision to authorize the system to operate.
Continuous Monitoring and Updates
- After authorization, continue periodic assessments and monitoring to detect new risks and changes in the risk profile.
- Update the SSP, risk assessment reports, and POA&M as necessary reflecting changes in the environment, technology, or operations.
Conducting a comprehensive cyber risk assessment is an ongoing process essential for maintaining FISMA compliance. It requires a vigilant approach to new threats and system changes, and an understanding that risk management is a continuous process aimed at securing federal information systems against evolving threats.
