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Java安全之挖掘回显链

0x00 前言

前文中叙述反序列化回显只是为了拿到Request和Response对象。在这里说的的回显链其实就是通过一连串反射代码获取到该Request对象。

0x01 回显链挖掘

借助Java Object Searche工具根据工具说明文档，在tomcat中下断点，然后在IDEA的Evaluate中执行索引语句。

Java安全之挖掘回显链

TargetObject = {org.apache.tomcat.util.threads.TaskThread} 
  ---> group = {java.lang.ThreadGroup} 
   ---> threads = {class [Ljava.lang.Thread;} 
    ---> [14] = {java.lang.Thread} 
     ---> target = {org.apache.tomcat.util.net.NioEndpoint$Poller} 
      ---> this$0 = {org.apache.tomcat.util.net.NioEndpoint} 
         ---> handler = {org.apache.coyote.AbstractProtocol$ConnectionHandler} 
          ---> global = {org.apache.coyote.RequestGroupInfo}

根据得出结果在Evaluate中进行查看

Java安全之挖掘回显链

获取group

编写代码获取该对象

Field group = Class.forName("org.apache.tomcat.util.threads.TaskThread").getDeclaredField("group");
            group.setAccessible(true);
            ThreadGroup threadGroup = (ThreadGroup) group.get(thread);

获取测试错误了，其原因是因为org.apache.tomcat.util.threads.TaskThread中并没有group变量，该类继承了Thread类，该变量在Thread类中。

Java安全之挖掘回显链

 Field group = Class.forName("java.lang.Thread").getDeclaredField("group");
            group.setAccessible(true);
            ThreadGroup threadGroup = (ThreadGroup) group.get(thread);

获取成功。

Java安全之挖掘回显链

获取thread

ThreadGroup threadGroup = (ThreadGroup) group.get(thread);
Field threads = Class.forName("java.lang.ThreadGroup").getDeclaredField("threads");
threads.setAccessible(true);
Thread[] thread1 = (Thread[])threads.get(threadGroup);

Java安全之挖掘回显链

获取target

发现thread并不是每一次都是14，需要这里采用获取线程名称进行定位对于的thread。

Java安全之挖掘回显链

if (thread2.getName().contains("http-nio")&&thread2.getName().contains("ClientPoller-1"))

最终代码

package com;

import org.apache.coyote.RequestGroupInfo;
import org.apache.coyote.RequestInfo;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.lang.reflect.Field;
//TargetObject = {org.apache.tomcat.util.threads.TaskThread}
//  ---> group = {java.lang.ThreadGroup}
//   ---> threads = {class [Ljava.lang.Thread;}
//    ---> [14] = {java.lang.Thread}
//     ---> target = {org.apache.tomcat.util.net.NioEndpoint$Poller}
//      ---> this$0 = {org.apache.tomcat.util.net.NioEndpoint}
//         ---> handler = {org.apache.coyote.AbstractProtocol$ConnectionHandler}
//          ---> global = {org.apache.coyote.RequestGroupInfo}
@WebServlet("/test2Servlet")
public class test2Servlet extends HttpServlet {
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        Thread thread = Thread.currentThread();
        try {
            Class<?> aClass = Class.forName("java.lang.Thread");
            Field group = aClass.getDeclaredField("group");
            group.setAccessible(true);
            ThreadGroup threadGroup = (ThreadGroup) group.get(thread);
            Field threads = Class.forName("java.lang.ThreadGroup").getDeclaredField("threads");
            threads.setAccessible(true);
            Thread[] thread1 = (Thread[])threads.get(threadGroup);
            for (Thread thread2 : thread1) {
                if (thread2.getName().contains("http-nio")&&thread2.getName().contains("ClientPoller-1")){
                    Field target = Class.forName("java.lang.Thread").getDeclaredField("target");
                    target.setAccessible(true);
                    Object o = target.get(thread2);
                    Field this$0 = o.getClass().getDeclaredField("this$0");
                    this$0.setAccessible(true);
                    Object o1 = this$0.get(o);
                    Field handler = Class.forName("org.apache.tomcat.util.net.AbstractEndpoint").getDeclaredField("handler");
                    handler.setAccessible(true);
                    Object handler1 = handler.get(o1);

                    Field global = handler1.getClass().getDeclaredField("global");
                    global.setAccessible(true);
                    RequestGroupInfo requestGroupInfo = (RequestGroupInfo)global.get(handler1);

                    Field processors = Class.forName("org.apache.coyote.RequestGroupInfo").getDeclaredField("processors");
                    processors.setAccessible(true);
                    java.util.List<RequestInfo> RequestInfo_list = (java.util.List<RequestInfo>) processors.get(requestGroupInfo);
                    Field req = Class.forName("org.apache.coyote.RequestInfo").getDeclaredField("req");
                    req.setAccessible(true);
                    for (RequestInfo requestInfo : RequestInfo_list) {
                        org.apache.coyote.Request request1 = (org.apache.coyote.Request) req.get(requestInfo);
                        org.apache.catalina.connector.Request request2 = ( org.apache.catalina.connector.Request)request1.getNote(1);
                        org.apache.catalina.connector.Response response2 = request2.getResponse();
                        response2.getWriter().write("Success!!!");
                    }



                }
            }
//            for (Thread thread2 : thread1) {
//                System.out.println(thread2.getName());
//            }

//            if ()
//            thread1[14]
//            Field target = Class.forName("java.lang.Thread").getDeclaredField("target");
//            target.setAccessible(true);
//            Runnable runnable = (Runnable)target.get(thread1[13]);


        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }

    }

    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
        this.doPost(request, response);
    }
}

Java安全之挖掘回显链