Rev/Pwn

We have decided to put two common CTF categories together because they share tools and mindset: reverse engineering and pwn (also known as binary exploitation).

So you may be aware that some programming languages are compiled (such as C, Java, Rust), while others are interpreted (Python, JavaScript, PHP). To run a C program you first need to compile it to an executable binary (like a .exe file). Python on the other hand interprets the instructions directly from the source code.

main.c -> compiler -> main.exe
python.exe main.py

If you try to open an executable binary in a text editor you will be greeted by lots of incoherent characters. That is because the compiler has translated the source code to machine code. The art of reverse engineering tries to turn machine code into source code again!

Binary exploitation (pwn) challenges may include a step to reverse the machine code, but it is common that you will get the source code from the start. Here the goal is instead to figure out how insecure code can be exploited. If you give the binary unexpected input it might behave in an interesting way. What happens if the name you enter is too long? What if you order a negative amount of items? Can you circumvent certain checks?

Useful platforms

Useful tools

Try your skills

If you feel ready then you can try to solve out Rev/Pwn challenges (registration code: 1337). When you have solved three of them, head over to one of our CTF events and you will get a sticker!