Definition ∞ An external call issue occurs when smart contract interactions with other contracts cause vulnerabilities. This security concern materializes when a smart contract’s interaction with another contract or an external account introduces an exploitable flaw. Common manifestations include reentrancy vulnerabilities, where an external call recursively drains funds, or improper handling of unexpected return values. Gas limit considerations during such calls also present potential points of failure.
Context ∞ External call issues are a consistent focus in smart contract security audits and post-mortem analyses of exploits in decentralized applications. Developers are increasingly employing best practices, such as checks-effects-interactions patterns, to mitigate these risks. Ongoing research aims to develop safer inter-contract communication standards and automated vulnerability detection tools.