What Would Be the Vulnerable Code Structure That Violates the CEI Pattern? ⎊ Path

What Would Be the Vulnerable Code Structure That Violates the CEI Pattern?

A vulnerable code structure violates CEI by performing the external interaction before the state change. For example, a withdrawal function that first sends the Ether ( msg.sender.call{value: amount}("") ) and then updates the user's balance ( balance = 0 ) is vulnerable.

The attacker's fallback function is executed during the external call, allowing them to re-enter and withdraw again before the balance is zeroed.

Provide a Simple Code Example of a Function Following the CEI Pattern

How Do Solidity Modifiers like Nonreentrant Implement the CEI Principle?

How Did the DAO Hack in 2016 Utilize a Reentrancy Attack?

What Is the Checks-Effects-Interactions Pattern and How Does It Prevent Reentrancy?

Why Is Updating State before an External Call the Critical Part of the CEI Pattern?

What Specific Code Vulnerability in the DAO Contract Allowed the Reentrancy?

Can the CEI Pattern Be Applied to Other Security Vulnerabilities besides Reentrancy?

Provide an Example of How Two Functions Might Share a State That Could Be Exploited

Glossar

Vulnerable Code Structure

Structure ⎊ Vulnerable Code Structure refers to architectural or organizational deficiencies within a smart contract's codebase that create latent security weaknesses, even if individual functions appear correct.

Vulnerable Code

Concept ⎊ This term identifies segments of smart contract or exchange software logic that contain exploitable weaknesses, such as reentrancy bugs or improper access controls, which could compromise derivative positions or collateral.