Arbitrary Code Execution

https://github.com/Kannampuzha/Paint/blob/c9186f65cdf5e446d58014c054bad87bbb61f857/paint_app.py#L152

If python code is added to the [undo.rec](https://github.com/Kannampuzha/Paint/blob/master/undo.rec) file, when `undo` button is clicked it will run the code.

To fix:

1. You can use encryption, encrypt the data written in the [undo.rec](https://github.com/Kannampuzha/Paint/blob/master/undo.rec) file
2. Decoding the encrypted text in [undo.rec](https://github.com/Kannampuzha/Paint/blob/master/undo.rec) file in order to run the function to achieve the **undo feature**.

_**Note: You will have to make a function in which for all installations the encryption key is different.**_