Integer Overflow

An integer overflow occurs when an arithmetic operation attempts to create a numeric value that is outside the range that can be represented with a given number of bits. In smart contracts, this can lead to unexpected behavior, such as a variable wrapping around to a very small number or zero, which can be exploited to bypass balance checks.

For example, if a user has a balance represented by an unsigned integer, subtracting more than their balance could cause an underflow, resulting in an extremely large number. Attackers use these exploits to inflate their token balances or gain unauthorized permissions within a protocol.

Modern development environments for smart contracts now include built-in protections that automatically revert transactions if an overflow or underflow is detected. Despite these safeguards, understanding the mechanics of integer math remains crucial for security-conscious developers.

It serves as a reminder of how low-level technical details can have massive financial implications.