Intigriti29 · 2026-01-28 00:00
Intigriti 0126 CTF Challenge: Exploiting insecure postMessage handlers
At Intigriti, we host monthly web-based Capture The Flag (CTF) challenges as a way to engage with the security researcher community. January's challenge presented participants with CRYPTIGRITI, a cryptocurrency trading platform where users could buy and trade Bitcoin (BTC), Monero (XMR), and a custom digital currency, 1337COIN. This article provides a step-by-step walkthrough for solving January's CTF challenge while demonstrating techniques for exploiting insecure postMessage implementations...