CWSS

CWSS, or Common Weakness Scoring System, is a framework for assessing and prioritizing weaknesses found in software code and design, commonly represented as CWE entries. It provides a structured method to assign a numeric score to a weakness, enabling security teams to rank remediation efforts and allocate resources effectively.

The primary goal of CWSS is to help organizations focus on the most significant weaknesses across a software portfolio by considering multiple factors that influence risk, rather than relying on individual vulnerability reports alone. It is designed to be used during secure development lifecycles, security testing, and risk management activities.

CWSS scores are derived from multiple factors, typically including the likelihood that a weakness can be exploited, the potential impact of exploitation on confidentiality, integrity, and availability, the prevalence of the weakness across code bases or products, and the degree to which existing mitigations limit risk. The framework supports context-specific weighting to reflect an organization's technology, threat model, and remediation priorities.

CWSS complements the CWE taxonomy of software weaknesses and is related to other scoring systems such as CVSS, which focuses on vulnerabilities rather than weaknesses. Organizations may integrate CWSS into governance and risk assessment processes and use it alongside other metrics to guide remediation planning and measurement.

CWSS has evolved through community collaboration to provide a standardized approach for weakness scoring. While it offers a principled way to prioritize remediation, its effectiveness depends on the quality of data about weaknesses, the chosen weighting scheme, and ongoing maintenance to reflect changing threat landscapes. See also CWE and CVSS.