CVE-2025-4818 is a SQL Injection vulnerability identified in SourceCodester Doctor's Appointment System version 1.0. The vulnerability exists in the /admin/delete-doctor.php file, specifically in the handling of the GET parameter 'ID'. An attacker can manipulate this parameter to inject malicious SQL code, which the backend database executes. This flaw allows an unauthenticated remote attacker to interfere with the application's database queries without requiring any user interaction or privileges. The vulnerability is rated with a CVSS 4.0 score of 6.9 (medium severity), reflecting its network attack vector, low attack complexity, and no need for authentication or user interaction. The impact on confidentiality, integrity, and availability is rated as low individually but collectively significant enough to warrant concern. Although no public exploits are currently known in the wild, the vulnerability details have been disclosed publicly, increasing the risk of exploitation. The absence of patches or mitigation links suggests that the vendor has not yet released an official fix, leaving affected systems exposed. The vulnerability could allow attackers to delete, modify, or extract sensitive data related to doctors and appointments, potentially disrupting healthcare services and compromising patient data integrity and confidentiality.

For European organizations, especially healthcare providers using the SourceCodester Doctor's Appointment System, this vulnerability poses a tangible risk to patient data confidentiality and service availability. Successful exploitation could lead to unauthorized data access, data manipulation, or deletion of critical records, impacting healthcare operations and patient trust. Given the sensitive nature of healthcare data and strict regulatory frameworks like GDPR in Europe, a breach could result in significant legal and financial repercussions. Additionally, disruption of appointment scheduling could degrade healthcare service delivery. The medium CVSS score indicates moderate ease of exploitation, meaning attackers with minimal skills could potentially leverage this flaw remotely. The lack of authentication requirements further exacerbates the risk, making it accessible to a broad attacker base. European healthcare entities relying on this system without mitigations are therefore at risk of data breaches and operational disruptions.

Immediate mitigation should focus on input validation and sanitization of the 'ID' parameter in /admin/delete-doctor.php to prevent SQL injection. Implement parameterized queries or prepared statements to ensure that user input is not directly concatenated into SQL commands. Organizations should conduct a thorough code review of all input handling in the application to identify and remediate similar vulnerabilities. Until an official patch is released by SourceCodester, deploying a Web Application Firewall (WAF) with rules to detect and block SQL injection attempts targeting this endpoint can provide a temporary defense. Monitoring and logging access to the vulnerable endpoint should be enhanced to detect suspicious activities. Additionally, restricting access to the /admin directory by IP whitelisting or VPN access can reduce exposure. Organizations should also plan for timely patch management once a vendor fix becomes available and consider migrating to more secure, actively maintained appointment systems if feasible.