An Ontology of Defects for Ethereum and its Smart Contracts

• Comprehensive list of Ethereum defects, encompassing vulnerabilities and code flaws, taken from the research literature. • The Ethereum defects collected come with a description, code examples, and mitigation strategies. • A tagging system to fine-grain categorize Ethereum defects. • A visualization tool for easy exploration of Ethereum defects. With Ethereum’s rise as the leading platform for decentralized applications, securing Ethereum smart contracts, very often having a financial impact, becomes paramount. Existing research lacks a comprehensive overview of Ethereum defects (and the terminology is often inconsistent), making it difficult for researchers, developers, and industry professionals to navigate this nowadays critical topic. This necessitates a unified source of information detailing defects affecting Ethereum and its smart contracts, along with their root causes, impact, and mitigation strategies. In this paper, we propose a knowledge base of defects , encompassing security vulnerabilities and code flaws found in the Ethereum blockchain and its smart contracts. We started by performing a systematic literature review to identify the currently known defects and then created a hierarchical tag system to classify them. This system was then used to build an ontology allowing users to easily search and learn about Ethereum defects. We also implemented EDOV, a tool to graphically navigate and explore the ontology, perform search queries, and visualize defect details, such as examples of defective/fixed code. As new defects may appear in the future, the ontology and the tool are built with extensibility in mind. We believe this research is a valuable contribution to helping developers and practitioners avoid common mistakes, improving the overall security and reliability of the Ethereum ecosystem.