Smart Contract Vulnerability Detection Based on Symbolic Execution Technology

With the rapid development of the blockchain, smart contract technology has been widely applied. The number of smart contracts has grown at a high rate and nearly at an average of thousands per day. However, the correctness and security of the smart contract itself are facing huge problems. The well-known DAO vulnerability, and Parity multi-signature wallet' vulnerabilities have leaded to a hundreds of millions dollars loss, and they are both caused by the security problems of smart contracts. Once the smart contract vulnerability is exploited, it is very likely to bring the loss of cryptocurrencies, the disorder of the financial order and other catastrophic consequences. Therefore the security of smart contracts is imminent. This project has designed and implemented a vulnerability detection system of Ethereum smart contract. The system uses the assembly instruction sequences of the smart contract to generate the control flow graph, then performs symbolic execution and vulnerability constraint solving over the control flow. The system can detect some common types of vulnerabilities, such as the integer overflow and underflow vulnerability, reentry vulnerability and unchecked call return value vulnerability. It has a high accuracy of detection result, and gives support for export vulnerability report.