yETH-hack

A proof of concept demonstrating an attack that occurred on yETH.

The Vulnerability

The attack exploited unsafe math operations in Pool.vy:1274. The original code used unsafe_div, unsafe_sub, and unsafe_mul which bypass Vyper's built-in overflow/underflow checks.

Fix: Using safe math (standard arithmetic operators) instead of unsafe math causes the attack to revert. See the commented code in src/Pool.vy at line 1272-1276 and test_attack in test/Hack.t.sol.

Installation

1. Clone the repository

   git clone https://github.com/johnnyonline/yETH-hack.git
   cd yETH-hack

2. Set up virtual environment

   uv venv
   source .venv/bin/activate  # On Windows: .venv\Scripts\activate
   deactivate  # To deactivate the venv

3. Install dependencies

   # Install all dependencies
   uv sync

   Note: This project uses uv for faster dependency installation. If you don't have uv installed, you can install it with pip install uv or follow the installation instructions.

4. Environment setup

   cp .env.example .env
   # Edit .env with your API keys and configuration

Usage

Build:

forge b

Test:

forge t --mt test_attack -vv