Consequences of this buffer overflow?

Question

So here I believe I have a small buffer overflow problem I found when reviewing someone else\'s code. It immediately struck me as incorrect, and potentially dangerous, but a

Answer 1

The reason the string is printing fine in the debugger is that as part of the sprintf, the trailing NULL character is being written to memory (in this case beyond the buffer you allocated) and when it comes to reading the string the NULL character is present to terminate the string as expected.

The problem is that the byte containing the NULL character hasn't been allocated as part of the original new and so could be used for a different allocation later. In this case, when you come to read the string afterwards you will likely get your original string with garbage appended.