  Blockchain technology (BT) Ethereum Smart Contracts allows programmable
transactions that involve the transfer of monetary assets among peers on a BT
network independent of a central authorizing agency. Ethereum Smart Contracts
are programs that are deployed as decentralized applications, having the
building blocks of the blockchain consensus protocol. This technology enables
consumers to make agreements in a transparent and conflict-free environment.
However, the security vulnerabilities within these smart contracts are a
potential threat to the applications and their consumers and have shown in the
past to cause huge financial losses. In this paper, we propose a framework that
combines static and dynamic analysis to detect Denial of Service (DoS)
vulnerability due to an unexpected revert in Ethereum Smart Contracts. Our
framework, SmartScan, statically scans smart contracts under test (SCUTs) to
identify patterns that are potentially vulnerable in these SCUTs and then uses
dynamic analysis to precisely confirm their exploitability of the
DoS-Unexpected Revert vulnerability, thus achieving increased performance and
more precise results. We evaluated SmartScan on a set of 500 smart contracts
collected from the Etherscan. Our approach shows an improvement in precision
and recall when compared to available state-of-the-art techniques.
