Empirical Study of Impact of Solidity Compiler Updates on Vulnerabilities in Ethereum Smart Contracts

Abstract

Vulnerabilities in Ethereum smart contracts often cause significant financial damage. Whereas the Solidity compiler has been updated to mitigate vulnerabilities, the effectiveness of these updates remains undisclosed to the best of our knowledge. In this paper, we aim to shed light on the impact of compiler versions on reducing vulnerabilities in Ethereum smart contracts. To achieve this, we collected 497,344 contracts with Solidity source codes from the Ethereum blockchain and analyzed their vulnerabilities. For three vulnerabilities of high severity, i.e., Locked Money , Using tx.origin , and Unchecked Call , we illustrate their appearance rate changes, showing decreases attributed to major updates of the Solidity compiler. Subsequently, we found the following four key insights. Firstly, updates to version 0.6 and version 0.8 led to decreased appearance rates for Locked Money . Secondly, regardless of compiler updates, the appearance rate for Using tx.origin was significantly low. Thirdly, the appearance rate for Unchecked Call significantly decreased from version 0.5 to version 0.8. Lastly, as an incidental discovery from our empirical study, we identified implications for code clones, which merit attention from subsequent researchers and developers.