[C++] Basic Buffer Overflow Vulnerable Code

[K1u]

Something I wrote for a new section on my site, angablade might make some on vulns in php soon.

Vulnerable:

#include <iostream>

int main(void)
{
   char ownme[255] = { 0 };
   std::cin >> ownme;
   getchar();
}

Solution:

The code may be exploited by entering a value of 256 chars, causing just one form of a very basic Buffer Overflow.

This occurs logically due to more going in than meant to go in.

This concept may not be easy to all, so I will explain through a example, if I were to fill a balloon with more air than it could take it would explode, very simple example to understand.

More information: Buffer Overflow - http://en.wikipedia.org/wiki/Buffer_overflow

Writing a secure version of the code:

#include <iostream>

int main(void)
{
   char hahacantownme[256] = { 0 };
   std::cin.getline(hahacantownme, 255);
   getchar();
}

Notice that I use the max which is 256 and only permit to get 1 lower than this.

I hope you enjoyed and also learned something.