Buffer
Overflow Causes. ©2002, Jedidiah R. Crandall, Susan L. Gerhart, Jan G.
Hogle.
http://sfsecurity.pr.erau.edu
Formatting and logical errors
Sometimes its not the size of the input but the value of the input that causes a buffer to overflow.
The input might be an integer that you want to convert to an ASCII string. The buffer needs to be big enough to hold all of the digits of the biggest integer someone could enter. Otherwise the program might be vulnerable to program crashes or data corruption.