Fixing Vulnerabilities Potentially Hinders Maintainability

TL;DR

This study investigates how security patches in open-source software impact maintainability, revealing a significant trade-off where nearly 42% of patches hinder maintainability by increasing complexity and code size.

Contribution

It provides empirical evidence of the maintainability-security trade-off in open-source patches and highlights the need for careful patching practices and improved tools.

Findings

41.90% of patches hinder maintainability

38.29% of patches increase complexity

37.87% of patches increase LOCs per unit

Abstract

Security is a requirement of utmost importance to produce high-quality software. However, there is still a considerable amount of vulnerabilities being discovered and fixed almost weekly. We hypothesize that developers affect the maintainability of their codebases when patching vulnerabilities. This paper evaluates the impact of patches to improve security on the maintainability of open-source software. Maintainability is measured based on the Better Code Hub's model of 10 guidelines on a dataset, including 1300 security-related commits. Results show evidence of a trade-off between security and maintainability for 41.90% of the cases, i.e., developers may hinder software maintainability. Our analysis shows that 38.29% of patches increased software complexity and 37.87% of patches increased the percentage of LOCs per unit. The implications of our study are that changes to codebases while patching vulnerabilities need to be performed with extra care; tools for patch risk assessment should be integrated into the CI/CD pipeline; computer science curricula needs to be updated; and, more secure programming languages are necessary.