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Cross-Chain Bridge Bugs: A Growing Problem



January 31st, 2023

Cross-chain bridges have become the most popular solution to support asset interoperability between heterogeneous blockchains. However, while providing efficient and flexible cross-chain asset transfer, the complex workflow involving both on-chain smart contracts and off-chain programs causes emerging security issues as we highlighted in a recent blog post. Last year, there were a dozen severe attacks against cross-chain bridges, causing billions of dollars of losses.

Bugs in Cross-Chain Bridges

Cross-chain bridges are applications that act as intermediaries between users on different blockchains. Users lock various tokens on different blockchains to the bridge, and the bridge takes responsibility for validating these locked tokens, performing cross-chain trading logic like deposit or swap, and unlocking target tokens to users.

Cross-chain bridge bugs are software errors that affect the functionality and security of cross-chain bridges. These bugs can potentially be exploited by malicious actors to steal assets or data that is being transferred between different blockchain networks.

There are many different types of cross-chain bridge bugs, and the type of bug will depend on the specific software and technology that is being used. 

Some of the most common types of cross-chain bridge bugs include:

  • Vulnerabilities in smart contract code, which can be exploited by hackers to gain unauthorized access to the network and steal assets.
  • Inconsistencies between on-chain and off-chain components, which can cause the bridge to malfunction or become unresponsive.
  • Bugs in the bridge’s transaction validation logic, which can allow invalid or malicious transactions to be processed.
  • Security vulnerabilities in the bridge’s software or infrastructure, which can be exploited by hackers to gain access to the network or disrupt its operations.

How to Avoid Cross-Chain Bridge Bugs

To prevent cross-chain bridge bugs from occurring, it is important for developers to carefully test and audit their code to ensure that it is free from vulnerabilities. This can help protect users’ assets and data, and can also help to maintain trust and confidence in the cross-chain bridge technology.

To mitigate these vulnerabilities, it is important for users to carefully research and evaluate cross-chain bridges before using them. This should include looking for signs of strong security and reliability, as well as considering the potential risks and rewards of using a particular bridge.

By taking these steps, users can help to ensure that they are using a reliable and secure cross-chain bridge solution for their needs. This can help to protect their assets and data, and can also help to support the growth and development of the broader blockchain ecosystem.

At Halborn, we’re always happy to help you review your source code for these types of errors and more. To talk to one of our blockchain experts about cross-chain bridge source code reviews or any other Web3 security topics, drop us a line at halborn@protonmail.com.