Measurements of the Most Significant Software Security Weaknesses
This work addresses the need for more balanced and reliable metrics in software security for developers and analysts, though it is incremental as it builds on existing CWE frameworks.
The authors tackled the problem of accurately ranking software security weaknesses by identifying that the existing Common Weakness Enumeration (CWE) metric heavily biases frequency over exploitability and impact. They proposed improvements, including linearizing the frequency distribution with a double log function, and provided updated top lists for 2019 with comparisons to previous rankings.
In this work, we provide a metric to calculate the most significant software security weaknesses as defined by an aggregate metric of the frequency, exploitability, and impact of related vulnerabilities. The Common Weakness Enumeration (CWE) is a well-known and used list of software security weaknesses. The CWE community publishes such an aggregate metric to calculate the `Most Dangerous Software Errors'. However, we find that the published equation highly biases frequency and almost ignores exploitability and impact in generating top lists of varying sizes. This is due to the differences in the distributions of the component metric values. To mitigate this, we linearize the frequency distribution using a double log function. We then propose a variety of other improvements, provide top lists of the most significant CWEs for 2019, provide an analysis of the identified software security weaknesses, and compare them against previously published top lists.