Hour one: reconnaissance. The target web app looked ordinary—forms, endpoints, a few JavaScript libraries. My notes became a map: parameters, cookies, user roles. I moved carefully, fingerprinting frameworks and tracing hidden inputs. A misconfigured template engine glinted like a seam in concrete. I smiled; that seam was a promise.

When it finished submitting, I sat back and let the relief wash over me. The rain had stopped. I didn't know the score, but I knew I had followed the methodology: observe, hypothesize, test, and document. Passing or failing would be a single line in someone else's system, but the real reward was the clarity of the narrative I left behind—the trail of logic that turned curiosity into a usable report.

I documented every step as I went: the exact requests, the payloads, the timing, and why one approach failed while another succeeded. The exam wasn't a race to the first shell; it was a careful record of reasoning. I took screenshots, saved raw responses, and wrote clear remediation notes—how input validation could be tightened, how templates should be sandboxed, and which configuration flags to change.

Hour five: pivot. The upload allowed me to write a template that the server would render. I needed to get code execution without breaking the app or tripping filters. I built a tiny, brittle gadget: a template that called an innocuous-seeming function but passed it a crafted string that forced the interpreter to evaluate something deeper. When the server rendered it, a single line of output confirmed my foothold: a banner string displayed only to admins.

Hour three: exploit development. I crafted payloads slowly, watching responses for the faintest change in whitespace, an extra header, anything. One payload returned a JSON with an odd key. I chased it into a file upload handler that accepted more than it should. The upload stored user data in a predictable path—perfect for the next step.