SolScope: Effectively Hunting Potential Permission Backdoor Threats in Smart Contracts

Abstract

The popularity of smart contracts on Ethereum blockchain has completely changed the way people perceive decentralized applications. With the expansion of smart contracts in areas such as DeFi and NFTs, more and more fraudulent contracts are emerging, causing users to suffer huge losses. In most cases, malicious users create their own fraudulent projects and lure other users to participate. One significant security threat in maliciously developed smart contracts is permission backdoor, which enable bad actors to manipulate other users’ funds as super administrators.In this paper, we propose and implement SolScope, an automated analyzer for effectively hunting potential permission backdoor threats in smart contracts. SolScope adopts an iterative algorithm that integrates symbolic execution and value summary. We evaluate SolScope on a vulnerability dataset of 524 manually verified smart contracts. SolScope is capable of not only accurately and effienctly detecting backdoor threats, but also generating reports that describe state variables affected by the backdoor and a function sequence that triggers the backdoor.