integer underflow
a counting mistake where a number drops below what a program can hold
Programs store numbers in fixed-size slots. If a subtraction produces a value below the smallest the slot can hold, the result comes out wrong, often as a very large number. If the program then uses that number to decide how much data to read or copy, it can overwrite memory. Attackers use this to crash a program or make it run their code.
Think of it as
Like a car's trip meter rolling back past zero and suddenly showing 99,999.
Ideas that use this term