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dc2020q - bytecoooding golf shellcoding

by adamd

This was a golf challenge, part of dc2020q. (CTFtime)

Points: 460
Was solved by: 2 teams
PCAPs: download

You may spawn the server:

On your laptop
  • Install docker
  • docker pull archiveooo/pub:bytecoooding (docker-saved download)
  • docker run -d --name bytecoooding archiveooo/pub:bytecoooding
  • Local IP: docker inspect bytecoooding -f '{{ .NetworkSettings.Networks.bridge.IPAddress }}'
  • Connect to that IP:5000 — Remember to docker rm -f when done.
On your laptop (full source)
  • Install docker and pip install PyYAML coloredlogs
  • git clone https://github.com/o-o-overflow/dc2020q-bytecoooding-public
  • cd bytecoooding
  • ./spawner --log-level=INFO
  • Connect to the ip:port displayed
Hosted by OOO Right now we're asking players to login first.

Description

golf_course

This was a golfing challenge

Golf challenges start with a very high score threshold, which periodically decreases until a team reaches it. At that point, the threshold is set for everyone and the challenge behaves like a regular jeopardy-style one. (Full rules).

Golf challenges borrow the speed element from 2019's speedrun format, rewarding teams that solve the challenge fast and lock the challenge threshold to a high value (where few teams will reach them, ensuring a high point value) but at a much slower pace. They also self-adjust both in difficulty (players set the final threshold) and in score (OOO's point system rewards challenges that are solved by few teams).

if u thought shellcoding was fun, wait until you try bytecoooding


Threshold starts at 8, and decrements by 1 approximately every 5 hours.

line_weight bytecode-docker.tar.gz

Hints

None yet :(
If you wish, you can contribute some.

Source

Spoilers ahead! Code for this challenge is publicly available.