Warning: This project is highly insecure as it contains hard-coded secrets, passwords and a RCE.
In this application, your mission is to find the system vulnerability with usual vulnerability research methodologies. When you found it, you'll able to exploit the system.
If you'd like to know why you are researching a todo app, the reason is when software developers learn a new programming language or a new framework, they often develop a todo application which helps to understand the language or the framework better. Therefore maybe this application helps you to understand basic vulnerability researches methodologies.
Who knows maybe this application will be your first step in your vulnerability researcher career.
I hope you'll enjoy it and good luck.