Rainfall is an iso challenge slightly more complex than Snow Crash. You will have to dive deep into reverse engineering, learn to reconstruct a code, and understand it to detect faults. Will you reach the last level?
Security challenges focused on binaries: buffer overflows, printf insertions, shellcode injections and binary analysis.

General instructions

To make this project, you will have to use a VMV(64 bits). Once you have started your machine with the ISO provided with this subject, if your configuration is right, you will get a simple prompt with an IP :

Then, you will be able to log-in using the following couple of login:password :
level00:level00
You really shoud use the SSH connection available on port 4242 :
$> ssh level0@[VM_IP] -p 4242
Once logged-in, you will have to find a way to read the ".pass" file with the "levelX" user account of the next level (X = numéro next level).
This ".pass" file is located at the home root of each (level0 exclu) user.

Ressources

Exploits

• Buffer overflows
• Format string attacks
• Return-to-libc

Helpers

• Pattern generator
• Shellcode list

Learn more

• Learn assembly basics
• The holy grail of assembler documentation ❤
• Additional documentation on buffer overflows attacks

Architecture

This project can be separated into three parts :

• bonus[0-3] : This part concerns the bonuses that allowed me to go beyond a rate of 100/100.
• doc : Documentation that I deemed necessary to write for the good understanding of certain exploits.
• level[0-9] : This is the mandatory part.

Levels and bonuses

All the folders belonging to these two parts are made up as following :

• flag
• Ressources (Everything I needed to prove my results during the evaluation besides the walkthrough file)
  • asm_analysis.md : Full and detailed analysis of current level binary assembly code.
  • script.sh : Code and comments to test the source file.
  • websites.txt : (Optional) Lists of useful websites, helping to solve the level.
• source : Source code in pseudo C/CPP of the binary.
• walkthrough.md : Step-by-step procedure.

Minimal setup requirements of the VM

For this project, I used VirtualBox in order to create the VM. You will also need to download the ISO, avaible in the 42 school intranet.

• Name : RainFall
• Type : Linux
• Version : Ubuntu (64-bit)
• RAM : 1024 MB
• CPU : 1
• Network access mode : bridge
• Port : 4242

Rate : 125/100