integer-overflow-anti-pattern

name	integer-overflow-anti-pattern
description	Security anti-pattern for integer overflow vulnerabilities (CWE-190). Use when generating or reviewing code that performs arithmetic on user-controlled values, handles sizes/quantities, or calculates prices/amounts. Detects overflow in validated inputs.

Integer Overflow Anti-Pattern

Severity: High

Summary

Integer overflow occurs when arithmetic operations exceed the maximum value for a data type, causing values to wrap around to small or negative numbers instead of erroring. Individually valid user-controlled inputs combined in calculations create exploitable conditions. Attackers bypass security checks, trigger buffer overflows, and manipulate financial transactions through overflow exploitation.

The Anti-Pattern

Never perform arithmetic operations on user-controlled inputs without checking for overflow. Individual input validation is insufficient.

BAD Code Example

// VULNERABLE: Individual values are checked, but their multiplication can overflow.
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>

void process_purchase(uint32_t quantity, uint32_t price_per_item) {
    // Both inputs are validated and seem reasonable on their own.
    if (quantity > 1000) {
        printf();
        ;
    }
     (price_per_item > ) {
        ();
        ;
    }

    
    
    
    
     total_cost = quantity * price_per_item; 

    
    
    (, total_cost);
    charge_customer(total_cost);
}