Welcome to my series of writeups for n00bzunit3d 2024 capture-the-flag competition. In this post, we look at the programming/numbers 2 challenge. First, let’s look at the challenge. The challenge runs on a server and requires to connect remotely to access the challenge.

Connecting to the challenge, we are asked 100 of math problems (I answered the last one wrong on purpose, I promise).

Welcome to Numbers 2! Time to step up the game...
Current round: 1 of 100
Give me the greatest common divisor of 30 and 32: 2
Correct!
Current round: 2 of 100
Give me the greatest prime factor of 50: 5
Correct!
Current round: 3 of 100
Give me the least common multiple of 252 and 359: 1
Wrong!

While one could sit there for an hour or two and answer 100 math problems, we cannot be bothered. We wrote a simple python script that solves the questions and Voilà! Le flag

Current round: 100 of 100
Give me the least common multiple of 4484 and 9688:
answer: 10860248
Correct!
Good job! Here's your flag: n00bz{REDACTED}