CIA Rating

Overview

The CIA rating system is used to assess the security impact of assets or vulnerabilities based on three core security principles: Confidentiality, Integrity, and Availability. This rating helps prioritize security efforts and risk mitigation strategies.

Rating Scale

The CIA rating uses a numeric scale from 0 to 5, categorized into six severity levels:

Rating Range	Severity Level	Description
0 - 1.0	Very Low/Negligible	Minimal or no security impact
1.1 - 1.9	Low	Limited security impact
2.0 - 2.9	Moderate	Noticeable security impact
3.0 - 3.9	Moderate-High	Significant security impact
4.0 - 4.5	High	Serious security impact
4.6 - 5.0	Very High	Critical security impact

Rating Definitions

Very Low/Negligible (0 - 1.0)

• Impact: Minimal to no impact on security posture

• Action: Routine monitoring sufficient

• Example: Public information with no sensitivity

Low (1.1 - 1.9)

• Impact: Limited effect on operations or data

• Action: Address during regular maintenance cycles

• Example: Non-critical system logs

Moderate (2.0 - 2.9)

• Impact: Noticeable disruption or exposure risk

• Action: Plan remediation within standard timelines

• Example: Internal documentation with limited sensitivity

Moderate-High (3.0 - 3.9)

• Impact: Significant disruption or data exposure

• Action: Prioritize for near-term remediation

• Example: Customer data without financial information

High (4.0 - 4.5)

• Impact: Serious compromise of security or operations

• Action: Immediate attention and rapid remediation required

• Example: Financial records or authentication systems

Very High (≥ 4.6)

• Impact: Critical security breach or operational failure

• Action: Emergency response and immediate mitigation

• Example: Core infrastructure or highly sensitive data

Application

CIA ratings can be applied to:

• Assets: Rate the criticality of data, systems, or resources

• Vulnerabilities: Assess potential impact of security weaknesses

• Incidents: Evaluate severity of security events

• Risk Assessment: Quantify overall security risk

Best Practices

1. Consistency: Apply ratings uniformly across the organization

2. Context: Consider business impact and environmental factors

3. Review: Regularly reassess ratings as conditions change

4. Documentation: Record rationale for assigned ratings

5. Stakeholder Input: Involve relevant teams in rating decisions

Related Concepts

• CVSS (Common Vulnerability Scoring System): Industry standard for vulnerability severity

• Risk Matrix: Combines likelihood and impact for comprehensive risk assessment

• Security Controls: Implement controls appropriate to CIA ratings