CVE-2025-7540 is a critical SQL Injection vulnerability identified in version 1.0 of the code-projects Online Appointment Booking System, specifically within the /getclinic.php file. The vulnerability arises from improper sanitization of the 'townid' parameter, which allows an attacker to inject malicious SQL code remotely without requiring authentication or user interaction. This flaw enables an attacker to manipulate backend database queries, potentially leading to unauthorized data access, data modification, or even full database compromise. The vulnerability is classified with a CVSS 4.0 base score of 6.9, indicating a medium severity level, with an exploitability rating of low complexity and no privileges or user interaction required. Although the exploit has been publicly disclosed, there are no known active exploits in the wild at this time. Other parameters in the application may also be vulnerable, suggesting a broader issue with input validation in the affected system. The Online Appointment Booking System is typically used by healthcare providers, clinics, and other service organizations to manage appointments, making the confidentiality and integrity of patient or client data a critical concern.

For European organizations, particularly those in healthcare and service sectors relying on the code-projects Online Appointment Booking System, this vulnerability poses significant risks. Exploitation could lead to unauthorized disclosure of sensitive personal data, including patient information, violating GDPR requirements and potentially resulting in substantial regulatory penalties. Data integrity could also be compromised, affecting appointment schedules and operational reliability. The ability to remotely exploit this vulnerability without authentication increases the attack surface, potentially allowing attackers to leverage the system as a foothold for further network intrusion. Disruption of appointment services could degrade trust and operational continuity. Given the critical nature of healthcare services in Europe, such an attack could have cascading effects on patient care and organizational reputation.

Immediate mitigation should focus on implementing rigorous input validation and parameterized queries or prepared statements within the /getclinic.php script to eliminate SQL injection vectors. Organizations should conduct a thorough code review of all input handling routines, especially those accepting user-supplied parameters, to identify and remediate similar vulnerabilities. Deploying Web Application Firewalls (WAFs) with custom rules to detect and block SQL injection attempts targeting the 'townid' parameter can provide interim protection. Regularly updating the Online Appointment Booking System to a patched version once released by the vendor is critical. In the absence of an official patch, organizations should consider isolating the affected system, restricting external access, or applying virtual patching techniques. Additionally, monitoring database logs for suspicious queries and implementing strict access controls on the database can help detect and limit potential exploitation. Finally, organizations should review and enhance their incident response plans to address potential data breaches stemming from this vulnerability.