[gynvael]

This is true, though I need to add the missing phrase - "CTF challenges typically do not involve zero days" in real world software.

They do however strictly involve zero days in software created for the purpose of the CTF - that's basically what CTFs are about.

[saagarjha]

Fair enough, although I would argue that a zero day in a menu-based heap massaging challenge is not really all that interesting :P

[gynvael]

Not saying it's interesting (in the terms of a real world application), but it technically is an 0-day ;)