Dolibarr CRM Command Injection

`# Exploit Title: Dolibarr CRM < 3.9.1 - Command Injection Vulnerability  
# Exploit Author: David Silveiro   
# Exploit Author Github: github.com/davidsilveiro  
# Exploit Author Twitter: twitter.com/david_silveiro   
# Vendor Homepage: https://www.dolibarr.org  
# Software Link: https://sourceforge.net/projects/dolibarr/files/  
# Date: Zero Day  
  
Dolibarr ERP is a modern CRM to manage your company.It's opensource software,   
designed for small and medium companies, foundations and freelancers.  
  
It seems Dolibarr is open to Command Injection via the backup tool available  
to administrative users. While the intention of the developers wasn't to allow  
shell access, they've happened to do just that. It could be argued that the   
assumption that's been made is simply; "But he who has Admin on the CRM,  
has Admin on the Server".  
  
As we know, that's not always the case. Especially if the Server Administrator  
is unaware.  
  
Vulnerable files:  
  
GET: Dolibar_export.php  
POST: export.php  
  
POC:  
  
Navigate to;  
  
1) System Tools  
2) Backup  
  
You'll now notice 'Full Path to MysqlDump Command' on the right hand side.  
  
Enter;  
  
whoami;ifconfig;  
  
Then select;  
  
1) Compression 'None'  
2) Generate backup  
  
Continue by downloading the generated file on the upper right handside,  
where the output of our commands will be.  
`