CWE-128 (超界折返处理错误) — Vulnerability Class 1

CWE-128 represents a critical arithmetic weakness where integer values exceed their maximum capacity, causing them to wrap around to negative or undefined states. This flaw typically arises in languages with fixed-size data types, such as C or C++, when developers fail to validate input bounds before performing arithmetic operations. Attackers exploit this vulnerability by supplying carefully crafted inputs that trigger the overflow, potentially leading to buffer overflows, logic errors, or unauthorized access if the wrapped value is used for memory allocation or array indexing. To mitigate this risk, developers must implement rigorous input validation and employ safe arithmetic libraries that detect overflows before they occur. Additionally, using larger data types or unsigned integers where appropriate, combined with comprehensive unit testing for edge cases, ensures that boundary conditions are handled correctly, thereby preventing the unexpected behavior associated with wrap-around errors.