Exec CTF

Created by Elliott and Lemonyte
Python medium

Welcome to the Exec CTF challenge! Can you break out of a custom-built Python jail and successfully use exec()?

The flag is hidden in a print statement inside a compiled code object. This is provided to you in a variable named code

Your task is to execute it so that it prints the flag.

However, built-in execution functions like exec and eval are blocked by a custom security mechanism. The challenge is to bypass these restrictions and successfully run the code object.

To pass the challenge, the flag must be printed to stdout. Submit your Python code below to attempt the challenge.

You can download a local testing environment here. Need a hand or more detailed instructions? Shoot me a DM on Discord!

Originally hosted on whcc.club

Show hint

Security controls are rarely perfect, and this one is no exception. The execution environment uses a custom package, safe-exec. Understanding its behavior might help you find a way to run the code object.

Also, keep in mind that compiled code objects can contain nested exec and eval calls.

Try your code

                    
                        code = compile("print(...)", "<flag>", "exec")
                    
                

Click Submit to check your solution.