Abstract: Ethereum smart contracts have attracted significant attention in recent years,but their security vulnerabilities could result in substantial financial losses,highlighting the importance of detecting and patching these vulnerabilities.However,recent research primarily focuses on vulnerability detection rather than notable repair tools,which could result in high costs for manual repair.To address this challenge,this paper introduces OptimalFix,a novel framework that integrates vulnerability detection and patch,automatically generating secure patches for unsafe smart contracts.OptimalFix converts smart contracts into an intermediate representation and employs static detection to quickly identify and locate vulnerabilities.Subsequently,it conducts static program analysis,such as false positive filtering and program dependency analysis.The framework then generates patches using a template-based approach and selects the optimal template based on the results of the earlier static analysis,including detection outcomes and program analysis.OptimalFix is evaluated on three datasets,successfully fixing 90.2% of the vulnerabilities,with an average cost of only 900 milliseconds and a 6.7% increase in gas consumption.

Key words: Smart contract, Vulnerability detection, Static program analysis, Patching