Analysis of Major Attack Methods and Prevention Strategies in the Web3 Field in the First Half of 2022

In the field of blockchain security, the first half of 2022 presented some noteworthy trends. By analyzing the security incidents during this period, we can gain insights into the common attack methods used by hackers and how to better prevent these threats.

Overview of Losses Due to Vulnerabilities

According to data monitoring, there were a total of 42 major contract vulnerability attack incidents in the first half of 2022, resulting in approximately $644 million in losses. Among all the exploited vulnerabilities, logical or function design flaws were the most common, followed by validation issues and reentrancy vulnerabilities. This indicates that there is still significant room for improvement in security oversight during the contract design and development phases.

Analysis of Typical Security Incidents

At the beginning of February, a cross-chain bridge project suffered a massive attack, resulting in losses as high as $326 million. The hackers exploited a signature verification vulnerability in the contract, successfully forging accounts and minting tokens. This highlights the design vulnerabilities of cross-chain projects.

At the end of April, a lending protocol suffered a flash loan attack, resulting in losses exceeding $80 million. The attacker exploited a reentrancy vulnerability in the protocol, ultimately forcing the project to shut down. This incident once again confirms the dangers of reentrancy vulnerabilities and the power of flash loan attacks.

Common Types of Vulnerabilities

The most common vulnerabilities found during the audit process can be roughly divided into four categories:

1. Reentrancy attacks related to ERC721/ERC1155 standards
2. Contract Logic Design Defects
3. Key features lack permission control
4. Price Manipulation Vulnerability

Among them, contract logic vulnerabilities are still the most commonly exploited attack vectors by hackers. The good news is that through professional smart contract auditing and formal verification, most of these vulnerabilities can be detected and fixed during the development stage.

Prevention Suggestions

1. Strictly follow the "check-effect-interaction" design pattern to prevent reentrancy attacks.
2. Consider special scenarios comprehensively and improve contract function design.
3. Add strict permission controls for key functions
4. Use reliable oracles to avoid price manipulation.
5. Conduct a comprehensive security audit, with a particular focus on logical vulnerabilities.
6. Stay vigilant and continuously monitor the contract operation status.

In general, with the rapid development of the Web3 ecosystem, security issues remain a major challenge. Project teams need to pay more attention to contract security and comprehensively enhance safety through professional audits and other means. At the same time, the entire industry also needs to continuously summarize experiences and lessons learned to jointly build a more secure and reliable Web3 ecosystem.