CVE-2024-50991 identifies a Cross Site Scripting (XSS) vulnerability in the PHPGurukul User Management System version 1.0, located in the /ums-sp/admin/registered-users.php script. The vulnerability arises from improper sanitization of the 'fname' POST parameter, which allows an authenticated attacker with high privileges to inject malicious scripts. This type of XSS is categorized under CWE-79, where untrusted input is not correctly neutralized before being included in web pages, enabling script execution in the context of the victim's browser. The vulnerability requires the attacker to be authenticated and to interact with the system, limiting the attack surface but still posing a significant risk within trusted user environments. The CVSS 3.1 vector (AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N) indicates network attack vector, low attack complexity, high privileges required, user interaction needed, and a scope change affecting confidentiality and integrity but not availability. No patches or known exploits are currently available, indicating the vulnerability is newly disclosed. The affected system is a user management platform, which typically handles sensitive user data and administrative functions, increasing the potential impact of exploitation. Mitigation requires secure coding practices such as proper input validation, output encoding, and possibly implementing Content Security Policy (CSP) headers to reduce the risk of script execution.

The vulnerability primarily impacts the confidentiality and integrity of data within the PHPGurukul User Management System by allowing attackers to execute arbitrary scripts in the context of authenticated administrative users. This could lead to session hijacking, unauthorized actions, or data leakage. Since the vulnerability requires high privileges and user interaction, the risk is somewhat contained to insider threats or compromised accounts. However, in environments where administrative credentials are shared or weakly protected, the impact could be significant. Organizations relying on this system for user management may face data breaches or unauthorized modifications to user information. The lack of availability impact means system uptime is not directly threatened, but the trustworthiness of the system's data and operations is compromised. The absence of known exploits suggests limited current exploitation but also means organizations should act proactively to prevent future attacks.

To mitigate CVE-2024-50991, organizations should implement strict input validation and output encoding on the 'fname' POST parameter and any other user-supplied data to prevent script injection. Employing a robust web application firewall (WAF) with rules targeting XSS patterns can provide an additional layer of defense. Administrators should enforce the principle of least privilege to limit the number of users with high-level access and monitor for unusual activities within the admin interface. Implementing Content Security Policy (CSP) headers can reduce the impact of any injected scripts by restricting script sources. Regular security code reviews and penetration testing focused on input handling in the user management system are recommended. Since no official patch is available, consider isolating or restricting access to the vulnerable endpoint until a fix is released. Educate users about phishing and social engineering risks that could lead to credential compromise, which is a prerequisite for exploitation.