CVE-2025-7516 is a SQL Injection vulnerability identified in version 1.0 of the code-projects Online Appointment Booking System, specifically within the /cancelbookingpatient.php file. The vulnerability arises due to improper sanitization or validation of the 'appointment' parameter, which allows an attacker to inject malicious SQL code remotely without any authentication or user interaction. Exploiting this flaw can enable an attacker to manipulate backend database queries, potentially leading to unauthorized data access, data modification, or deletion. The vulnerability has a CVSS 4.0 base score of 6.9, indicating a medium severity level, with characteristics including network attack vector, low complexity, no privileges or user interaction required, and low impact on confidentiality, integrity, and availability. Although no public exploits are currently known in the wild, the vulnerability details have been disclosed publicly, increasing the risk of exploitation. The lack of available patches or mitigation links suggests that affected organizations must proactively implement defensive measures. Given the nature of appointment booking systems, which often handle sensitive personal and scheduling data, exploitation could compromise patient privacy and disrupt healthcare operations.

For European organizations, especially healthcare providers and clinics using the affected Online Appointment Booking System version 1.0, this vulnerability poses a significant risk. Successful exploitation could lead to unauthorized access to patient appointment data, potentially exposing sensitive personal health information, violating GDPR requirements, and resulting in regulatory penalties. Data integrity could be compromised by altering or deleting appointment records, causing operational disruptions and patient care delays. Availability impacts, while rated low, could still manifest as denial of service if database corruption occurs. The remote and unauthenticated nature of the attack vector increases the threat surface, allowing attackers to target vulnerable systems over the internet. Given the criticality of healthcare services and the sensitivity of patient data in Europe, this vulnerability could have serious reputational and financial consequences for affected organizations.

Since no official patches are currently available, European organizations should immediately implement input validation and sanitization controls on the 'appointment' parameter within the /cancelbookingpatient.php endpoint. Employing Web Application Firewalls (WAFs) with SQL Injection detection and prevention rules can help block malicious payloads targeting this vulnerability. Organizations should conduct thorough code reviews and penetration testing focused on SQL Injection vectors in their appointment booking systems. Restricting database user privileges to the minimum necessary can limit the impact of a successful injection. Monitoring and logging database queries and web application traffic for anomalous patterns can aid in early detection of exploitation attempts. Additionally, organizations should consider isolating the booking system from critical internal networks and ensure regular backups of appointment data to enable recovery in case of data tampering or loss.