CVE-2025-7753 is a critical SQL Injection vulnerability identified in version 1.0 of the code-projects Online Appointment Booking System. The vulnerability exists in the /admin/adddoctor.php file, specifically through the manipulation of the 'Username' parameter. This flaw allows an unauthenticated remote attacker to inject malicious SQL code into the backend database queries. Because the vulnerability does not require any authentication or user interaction, it can be exploited remotely by simply sending crafted requests to the vulnerable endpoint. The injection can lead to unauthorized data access, modification, or deletion, potentially compromising the confidentiality, integrity, and availability of the appointment booking system's data. Although the CVSS 4.0 score is 6.9 (medium severity), the classification as critical in the description likely reflects the potential impact on sensitive healthcare-related data and administrative functions. The vulnerability has been publicly disclosed, but there are no known exploits in the wild at this time. No official patches have been released yet, increasing the urgency for mitigation. The lack of secure coding practices in input validation and sanitization in the affected parameter is the root cause of this vulnerability.

For European organizations, particularly those in healthcare, clinics, or any service relying on the code-projects Online Appointment Booking System, this vulnerability poses a significant risk. Exploitation could lead to unauthorized access to sensitive patient and appointment data, violating GDPR requirements for data protection and privacy. Data breaches could result in regulatory penalties, reputational damage, and operational disruptions. The ability to modify or delete data could also disrupt appointment scheduling, impacting service delivery and patient care. Since the vulnerability is remotely exploitable without authentication, attackers could target exposed administrative interfaces over the internet, increasing the risk of widespread exploitation. Organizations using this system without timely mitigation may face increased risk of targeted attacks or opportunistic scanning by threat actors.

Given the absence of an official patch, European organizations should immediately implement compensating controls. These include restricting access to the /admin/adddoctor.php endpoint via network-level controls such as IP whitelisting or VPN-only access to administrative interfaces. Web Application Firewalls (WAFs) should be configured to detect and block SQL injection patterns targeting the 'Username' parameter. Input validation and sanitization should be enforced at the application level if source code access is available, applying parameterized queries or prepared statements to prevent injection. Regular monitoring of logs for suspicious activity related to the vulnerable endpoint is critical. Organizations should also plan for rapid patch deployment once an official fix is released and consider conducting penetration testing to verify the effectiveness of mitigations. Additionally, educating administrative users about the risk and encouraging strong authentication practices can reduce exposure.