Introduction
One day, while browsing the internet, I came across an XSS challenge: Intigriti’s 0421 XSS challenge - by @terjanq. Apart from the challenge itself being very attractive, what attracted me more was the author who created it.
Many of the security-related resources I found online that were more focused on front-end were maintained or contributed to by this author, such as Tiny XSS Payloads or the eye-opening XS-Leaks Wiki.
Intigriti seems to hold this kind of XSS challenge every month, and this was the hardest one they have ever held. The challenge lasted from 4/19 to 4/25, with a week to try, and only 15 people successfully solved it. In March, 45 people solved the challenge, and in February, 33 people did, so the number of people who solved it this time was indeed much less, indicating the difficulty of the challenge.
I spent about five days on it, and every time I got stuck, I thought, “I should give up and wait for the answer.” But then, from time to time, new ideas would come up, and I would try again. Finally, on the last day before the deadline, I solved it before the time limit, and when I did, I clenched my fists and shouted, “Too awesome!”
This article is about my experience in solving the challenge. I previously wrote an English version, but it was probably worse than an elementary school composition, so I decided to write a Chinese version to better express my thoughts. The title will have a “Part 1” because this article is about my solution, and the next article will be about the author’s solution, and the one after that will analyze other people’s solutions.
But it seems that my blog is cursed to break the series of articles that haven’t been written yet, so I hope I can make it through this time.