Description

Smart contract security remains one of the biggest challenges in blockchain development. With millions of dollars locked in smart contracts, a single vulnerability can lead to catastrophic losses.

I built Greybox - an open-source security scanning framework that combines static and dynamic analysis to help developers catch vulnerabilities before they reach production.

Inspiration

Inspired by Nuclei, Greybox is a template-based smart contract security scanner. This project was built for the EthSydney 2024 hackathon and awarded as a winning submission.

How Greybox Works

The scanner employs a two-phase approach towards smart contract security - a combination of whitebox and blackbox testing:

First, it performs static analysis by scanning contract source code against known vulnerability patterns. These patterns are defined in YAML templates, making it easy for security researchers to add new vulnerability definitions without diving into the core codebase.

Then, for potentially vulnerable code sections, Greybox switches to dynamic analysis. It deploys the contracts to a local Hardhat network and attempts to exploit the suspected vulnerabilities. This holistic approach significantly reduces false positives while maintaining thorough security coverage.

Beyond Basic Scanning

What sets Greybox apart is its focus on extensibility. While the initial release covers common vulnerabilities like integer overflows and gas limit issues (built over a weekend for the hackathon), the template-based system means anyone can add detection patterns for new attack vectors as they emerge.

The project also includes a browser-based UI that makes it accessible to developers who might not be security experts. Rather than just flagging issues, it provides detailed reports with context about each vulnerability and suggested mitigation strategies.

Check it out

You can find Greybox on GitHub here.