Definition ∞ An overflow checking bug occurs when a smart contract fails to properly verify if an arithmetic operation will exceed the maximum storage capacity of its data type. This oversight can lead to an integer overflow, where the computed value wraps around to an incorrect, typically much smaller, number. Such bugs are critical vulnerabilities that malicious actors can exploit to manipulate contract logic or drain funds. Proper implementation of overflow checks is essential for secure smart contract development.
Context ∞ The absence of adequate overflow checking has historically been a source of severe security breaches in smart contracts, resulting in substantial financial losses. Developers now widely employ safe math libraries or explicit runtime checks to prevent these arithmetic errors. Security audits specifically scrutinize code for such vulnerabilities, as they can compromise the integrity of asset balances and transaction logic. Preventing overflow checking bugs remains a high priority in the continuous effort to harden decentralized applications.