https://blog.wongcw.com/2019/01/05/%e9%98%bf%e9%87%8c%e9%9b%b2waf%e9%9b%b2%e9%98%b2%e8%ad%b7%e5%85%8d%e8%b2%bb%e9%a0%98%e5%8f%96%e4%be%86%e8%87%aa%e5%85%ac%e5%ae%89%e9%83%a8%e7%ac%ac%e4%b8%89%e7%a0%94%e7%a9%b6%e6%89%80-%e4%b8%ad/