Heap spraying

Heap spraying is like building a sandcastle at the beach. When you build a sandcastle, you start by piling sand into a big heap. This heap of sand is like the memory heap in a computer. Just like you can shape the sand heap into a castle, programs can shape the memory heap into data structures and objects.

But when people talk about heap spraying, they usually mean something more specific. Imagine you have a bucket with a hole in the bottom. If you fill the bucket with water, the water will drip out of the hole in a steady stream. Similarly, if you have a vulnerability in a program that lets you write data to a specific location in the memory heap, you can use that vulnerability to "spray" the heap with a certain pattern of data.

The idea behind heap spraying is to spray the heap with data that contains executable code, and then trick the program into running that code. The goal is to take control of the program's execution flow and make it do something it wasn't meant to do.

For example, imagine you're playing a game that has a vulnerability in the way it reads input from the keyboard. Normally, the game would read your keyboard input and use it to move your character around the screen. But if you can use the vulnerability to spray the heap with a pattern of data that includes executable code, you could make the game run any code you want. Maybe you could make it give you unlimited lives, or let you skip to the next level.

Of course, heap spraying is also used for more malicious purposes. Attackers can use heap spraying to inject malware into a victim's computer, or to take over a web browser and steal sensitive information like passwords and bank account details.

Overall, heap spraying is a powerful technique that exploits vulnerabilities in computer programs to take control of the program's execution flow. It's kind of like building a sandcastle, but with much more nefarious intentions.