Premium Support Tickets For WHMCS 1.2.10 Cross Site Scripting

Exploit Title: Premium Support Tickets For WHMCS Reflected XSSExploit Author: Sajibe KantiVendor: ModulesGardenVendor Homepage:https://www.modulesgarden.com/products/whmcs/premium-support-ticketsProduct Name: Premium Support Tickets For WHMCSProduct Version: v1.2.10Tested Version: WHMCS 8.10.1Tested on: Windows 10Vulnerabilities Discovered Date: 29/04/2024Description:The Premium Support Tickets For WHMCS plugin by ModulesGarden is vulnerableto a reflected cross-site scripting (XSS) attack. This vulnerability allowsan attacker to inject malicious JavaScript code into the "error&msg="parameter of the submitticket.php page, leading to the execution ofarbitrary code in the context of the victim's browser.Proof of Concept (POC):1. Identify a website that utilizes the Premium Support Tickets For WHMCSplugin by ModulesGarden.2. Navigate to the ticket submission page (submitticket.php).3. Select any department to open a new ticket.4. If you lack support credit points, you will receive an error messagewith the parameter "error&msg=clientarea_message_cantcreateinthisdept".5. Inject your payload into the "error&msg=" parameter.6. Construct the following URL with your payload:https://example.com/submitticket.php?PremiumSupportTickets=error&msg=%22/%3E%3CsvG%20onLoad=alert(/xss/)%3E7. Replace the payload with your desired XSS payload:   "<svg/onLoad=alert(/OPENBUGBOUNTY/)>"8. Visit the modified URL in your browser.9. Observe the XSS popup indicating successful exploitation of thevulnerability.Impact:Successful exploitation of this vulnerability could allow an attacker toexecute arbitrary JavaScript code in the context of an authenticated user'sbrowser session. This could lead to various attacks, including but notlimited to:- Theft of sensitive information (session cookies, credentials, etc.)- Phishing attacks targeting users of the affected WHMCS instance- Defacement of the website or redirection to malicious content- Browser-based attacks such as keylogging or screen capturingNote: This exploit is for educational purposes only. Unauthorized access toor modification of systems is illegal and unethical. Always obtain properauthorization before testing or exploiting vulnerabilities.