The solution for this chall can be found [here](https://github.com/werew/REstuffs/tree/master/CTFs/TUCTF2017/Pwn/vuln_chat_2.0)

Original writeup (https://github.com/werew/REstuffs/tree/master/CTFs/TUCTF2017/Pwn/vuln_chat_2.0).