Setup

How to run the challenge locally: - docker compose build - docker compose up

How to interact the challenge locally: - docker ps -a to show all running containers - docker exec -it public-ctf-1 bash to interact with the container shell

Your Tasks

I would provide the skeleton code for the exploiting script.

Your task is to read the hints in the script and complete the script.

Debug

You can debug on your container, or you can use mine:

docker pull n132/pwn:22.04 (I installed the tools with this script)

After pull-ing the image, you can run the container with this cmd: docker run --privileged -it n132/pwn:22.04 zsh

Then, you shall copy the vulnerable file to the container from the host, whose ID can be found by docker ps -a.

Run these commands on your host to perform copy:

docker cp ./bin/exp.py {Container ID}:/
docker cp ./bin/chal1 {Container ID}:/

Now we can debug the binary on your container by running python3 exp.py. Please don't forget to run tmux before debugging.

You can also find more cmds on this page: https://docs.docker.com/engine/reference/commandline/docker/.

Debug with GDB

This article would help you to debug with GDB.