Cybear Day 2026 - toyRNN

Apr 20, 2026

For Cornell Cybersec’s 2026 CTF and cybersec day, I wanted to try making a chall for others to play! Because I was quite busy with other things in life (AP exams are coming up!) I went with an AI model exploitation challenge which I was already the most comfortable with.

The Idea

Having done simple model inversion/gradient ascent challs in the past, I wanted my chall to be slightly more interesting/involved. Recently having read a paper on the HotFlip exploit (which I found fascinating), I wanted to try and incorporate that. Without forcing you to read the paper, HotFlip is an exploit that allows the attacker to craft an input for a neural text classifier