上月看的几部作品除了托尼史塔克的”Love you 3000”以外都记不太清了，应该说在情怀面前其他情节都变成了细枝末节。
This is a challenage from *CTF 2019 last weekend, a great CTF from sixstar team. For this particular challenge, you could found at least 3 avaliable Writeup (except for this one). The official Writeup here, one from shift-crops, and one from the Balsn Team.
I analyzed all three writeups and personally appreciated the one from Japanese player shift-crops the best. So the following paragraphs will focus on his method and try to clarify some glibc heap attack concepts he used.
The official Writeup and shift-crops’ did a great explanation about reversing process, so I’ll spare that part here. The exploit relays heavily on
unsorted bin attack, and here is a brief description of this technique.