Say It in German: Buffer Overflow

der Pufferüberlauf – buffer overflow

Oh, the dreaded buffer overflow.

I never really got how to overflow a buffer properly to get an exploit going. (And it was perfectly legal, done within the bounds of a supervised lab or homework assignment.)

A buffer is a temporary storage for data. A buffer overflow happens when too much data is written into the buffer that it gets written into memory locations next to the buffer. This can happen because there are no checks on the acceptable bounds for writing.

This is not a problem for high-level programming languages like Java since there are already checks in place, but is possible in lower-level languages like C.

Malicious people aka hackers and the like can intentionally overflow a buffer to alter a running program’s behaviour.

Etymology

The word Pufferüberlauf is a combination of Puffer = buffer + überlauf = to overflow.

I couldn’t seem to find much information as to why the term buffer came to be used in this particular sense of a temporary storage for data.

The original word buffer seemed to have had the meaning of lessening the sound made when one thing is struck against another, and later to lessen the impact of something.^[1]