Rating:

The binary is a simple HTTP server.
It has a buffer overflow vulnerability when getting the URL.
By causing an error during `sys_write` we can call an arbitrary system call with `rdi` under our control.
Thus, we can run a command by calling `sys_execve` with the arguments(`rsi`) set properly.

[writeup](https://ptr-yudai.hatenablog.com/entry/2019/04/25/141422#Binary-180pts-Server)

Original writeup (https://ptr-yudai.hatenablog.com/entry/2019/04/25/141422#Binary-180pts-Server).