The vulnerability CVE-2025-56243 is a reflected Cross-Site Scripting (XSS) flaw located in the register.php page of the PuneethReddyHC Event Management System version 1.0. Specifically, the event_id parameter passed via the HTTP GET method is not properly sanitized or encoded before being reflected in the web page output. This improper handling allows an attacker to inject arbitrary JavaScript code into the URL, which executes in the context of the victim's browser when they access the maliciously crafted link. Such XSS vulnerabilities can be exploited to steal session cookies, perform actions on behalf of the user, or redirect victims to malicious sites. The vulnerability does not require authentication or user privileges, and no user interaction beyond clicking a crafted link is necessary. Although no public exploits have been reported yet, the flaw is straightforward to exploit given the nature of reflected XSS attacks. The lack of a CVSS score indicates it is a newly published vulnerability, but the technical details and attack vector suggest a significant risk to affected systems. The PuneethReddyHC Event Management System is used to manage event registrations and related activities, making it a critical component for organizations relying on it for event operations. Failure to address this vulnerability could lead to compromised user data and trust.

For European organizations using the PuneethReddyHC Event Management System 1.0, this XSS vulnerability could result in unauthorized access to user sessions, theft of sensitive information such as login credentials, and manipulation of user interactions on the event registration platform. This could lead to data breaches involving personal data of event attendees, violating GDPR regulations and resulting in legal and financial penalties. Additionally, attackers could leverage the vulnerability to distribute malware or phishing content through the trusted event management interface, damaging organizational reputation and user trust. The impact extends beyond confidentiality to integrity and availability if attackers manipulate event registrations or disrupt normal operations. Given the widespread use of event management platforms in sectors such as education, corporate events, and public services across Europe, the potential for disruption and data compromise is significant. Organizations may also face indirect impacts such as loss of customer confidence and increased scrutiny from regulatory bodies.

To mitigate this vulnerability, organizations should immediately implement proper input validation and output encoding on the event_id GET parameter to neutralize malicious scripts. Employing context-aware encoding (e.g., HTML entity encoding) ensures that injected code is rendered harmless. Additionally, deploying a robust Content Security Policy (CSP) can restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. Regularly updating the PuneethReddyHC Event Management System to a patched version, once available, is critical. In the interim, organizations should consider implementing web application firewalls (WAFs) with rules designed to detect and block XSS attack patterns targeting the event_id parameter. User education on avoiding suspicious links and monitoring logs for unusual activity related to the register.php page can further enhance defense. Finally, conducting security audits and penetration testing focused on input handling will help identify and remediate similar vulnerabilities proactively.