Cybersecurity risk is typically calculated using the formula:
Risk Score=Likelihood of Threat×Impact of Threat
- Likelihood: The probability of a threat occurring, often based on historical data, expert judgment, or threat intelligence.
- Impact: The potential consequences of the threat, including financial, operational, or reputational damage
This basic formula can be adapted for more complex calculations by incorporating additional variables such as asset value, vulnerability severity, and exposure levels
Factors to Calculate Risk Scores
While severity and frequency (likelihood) are fundamental factors, other variables can enhance the accuracy of risk scoring:
- Technical Severity:
- Measured using frameworks like CVSS (Common Vulnerability Scoring System), which evaluates exploitability and impact metrics.
- Threat Intelligence:
- Includes information about active exploits, malware presence, or known vulnerabilities in the wild.
- Asset Value:
- Considers the business criticality of assets, such as core servers versus less critical devices.
- Exposure Levels:
- Assesses how exposed an asset is to potential threats based on its usage and security controls in place.
- Business Context:
- Evaluates the specific importance of an asset to the organization, including its role in critical business processes.
- Security Controls:
- Factors in the effectiveness of existing security measures like firewalls, encryption, and access controls.
- Tags and Business Groups:
- Assigns impact scores based on asset categorization (e.g., “critical systems”) to contextualize risk within organizational priorities.
- Financial Impact:
- Includes direct costs (e.g., fines or legal fees) and indirect costs (e.g., reputational damage or business interruption).
- Temporal and Environmental Adjustments:
- Adjust scores based on factors like exploit maturity or specific organizational environments.
- Frequency of Threat Events:
- Uses historical data to estimate how often a threat might occur annually (Annualized Rate of Occurrence).
Additional Factors Beyond Severity and Frequency
Yes, there can be more factors beyond severity and frequency to calculate a comprehensive cyber risk score:
- Attack Complexity: How difficult it is for an attacker to exploit a vulnerability.
- Privileges Required: The level of access needed for an attack.
- User Interaction: Whether user action is required for exploitation.
- Scope Changes: Whether a vulnerability impacts systems beyond its immediate environment.
Summary
Cybersecurity risk calculation involves multiple factors tailored to organizational needs. While severity and frequency are key components, incorporating variables like asset value, exposure levels, business context, and security controls provides a more nuanced understanding of risks. Advanced methodologies such as FAIR or CVSS frameworks further refine these calculations for precise prioritization and mitigation strategies
