pwnage

A simple Docker image for deploying CTF pwnable challenges in lightweight, jail-secured environments.

What is this?

pwnage is a slimmed-down Docker image you can use as the foundation for all your pwnable challenges. It wraps your binary in nsjail and exposes it over TCP using socat, so all you have to do is:

FROM pwnage

COPY chall /srv/app/run
COPY flag.txt /srv/app/flag.txt
RUN chmod 755 /srv/app/run

Whats running inside?

• Ubuntu Latest
• nsjail for sandboxing
• socat for TCP listener
• Non-root ctf user (UID 31337)
• Automatic jail creation for each connection
• Minimal writable filesystem (/srv/app only)

Things to know before you pwn.

• Your binary MUST be placed at /srv/app/run and be executable
• The container listens on port 1337 by default (configurable via PORT environment variable)
• Every connection spawns a new nsjail instance for isolation
• Custom nsjail settings can be provided by modifying the configuration and entrypoint.sh
• The environment is deliberately restrictive - your binary should be self-contained
• The challenge runs as a non-root user for added security

Advanced Usage

Custom Port

docker run -p 9999:1337 -e PORT=1337 my-challenge

Custom Resource Limits

docker run -e TIME_LIMIT=30 -e MEM_LIMIT=64 -e PROC_LIMIT=10 my-challenge

File Structure.

/srv
└── app
    ├── run        # your challenge binary
    └── flag.txt   # optional, read-only inside the jail

Please Contribute and Change things!