Tendenci 12.3.1 - CSV/ Formula Injection

#Exploit Title: Tendenci 12.3.1 - CSV/ Formula Injection
#Date: 2020-10-29
#Exploit Author: Mufaddal Masalawala
#Vendor Homepage: https://www.tendenci.com/
#Software Link: https://github.com/tendenci/tendenci
#Version: 12.3.1
#Payload:  =10+20+cmd|' /C calc'!A0
#Tested on: Kali Linux 2020.3
#Proof Of Concept:
CSV Injection (aka Excel Macro Injection or Formula Injection) exists in
Contact Us feature in Tendenci v12.3.1 via message field that is mistreated
while exporting to a CSV file.
To exploit this vulnerability:

   1. Go to contact us page and enter the payload "=10+20+cmd|' /C
   calc'!A0" in the message field and submit the form
   2. Login to the application and go to Forms section and export the
   contact us form entries
   3. Click on Export and save the CSV file downloaded
   4. Open the CSV file, allow all popups and our payload is executed
   (calculator is opened).