Integer overflow/ underflow exploitation tutorial

[Nytro]

nteger overflow/underflow exploitation tutorial

By Saif El Sherei

www.elsherei.com

Introduction:

I decided to get a bit more into Linux exploitation, so I thought it would be nice if I document

this as a good friend once said “ you think you understand something until you try to teach it “.

This is my first try at writing papers. This paper is my understanding of the subject. I understand

it might not be complete I am open for suggestions and modifications. I hope as this project helps others as it helped me. This paper is purely for education purposes.

Note:

the Exploitation methods explained in the below tutorial will not work on modern system

due to NX, ASLR, and modern kernel security mechanisms. If we continue this series we will

have a tutorial on bypassing some of these controls

What is an integer?

An integer in computing is a variable holding a real number without fractions. The size of int is

depending on the architecture. So on i386 arch (32-bit) the int is 32-bits.

An integer is represented in memory in binary.

Download:

http://packetstorm.igor.onlinedirect.bg/papers/attack/overflowunderflow-tutorial.pdf