Overview On June 13th, Uniswap Labs released a blog post announcing the release of the draft code for Uniswap V4, which includes an early open-source version of the Uniswap V4 core and peripheral libraries, as well as a draft of the technical whitepaper. Uniswap V4 introduces many new features, and this…

Overview Uniswap introduced the Permit2 authorization standard last year to improve the authorization experience for traditional ERC20 tokens. It offers gas efficiency, enhanced security compared to traditional ERC20 approvals, and easier management. This article provides an introduction to the Permit2 authorization standard and analyzes potential security risks associated with it. Permit Introduction

## I. Variable Storage/Assignment/Deletion:： ### 1.Do not store any sensitive information on the blockchain. #### Vulnerability Details: Due to the transparency of the blockchain, any contract data deployed on the chain is visible and transparent, even for variables that are marked as private. This is because the visibility of private…

## Overview This article provides a detailed analysis of the vulnerability issues caused by the Solidity compiler (0.5.8<= version <0.8.16) in the ABIv2 reencoding process due to the error handling of fixed-length `uint` and `bytes32` type arrays, and proposes relevant solutions and avoidance measures. ## Vulnerability details The ABI encoding…

Overview Among various security issues in smart contracts, the reentrancy vulnerability has always been the most harmful and occurs frequently. The vulnerability is caused by the contract not properly managing the order of changes to state variables when processing function calls. The most famous reentrancy exploit was the 2016 The DAO…

Solidity compiler medium-high risk vulnerability：Analysis of storage Write removal on conditional early termination [SOL-2022–7] ## Overview This article introduces the storage write removal of solidity compiler (0.8.13<=solidity<0.8.17) which caused by Yul optimization mechanism from the source code level and corresponding prevention measures in detail. Help contract developers to raise awareness…

Decentralized finance (often stylized as DeFi) is a form of finance built on blockchain technology. It does not rely on traditional financial institutions such as brokers, exchanges, or banks to provide financial instruments. Instead, DeFi utilizes smart contracts on the blockchain to carry out financial activities. There are numerous arbitrage…

Overview On April 13, 2023, Yearn Finance suffered an attack, resulting in a loss of approximately 10 million U.S. dollars.. This article will analyze the attack process and the reasons for the vulnerability. Attack Analysis This is an attack transaction： https://etherscan.io/tx/0xd55e43c1602b28d4fd4667ee445d570c8f298f5401cf04e62ec329759ecda95d The attacker initiated a flash loan from Balancer, borrowing 5 million DAI…

Overview Tokens with deflation mechanism on the blockchain are often attacked recently. This article discusses and analyzes why these tokens are attacked, and gives corresponding defense solutions. There are generally two ways to implement the deflation mechanism in tokens, one is the burn mechanism, and the other is the reflection mechanism…