CVE-2025-6355 is a critical SQL Injection vulnerability identified in version 1.0 of the SourceCodester Online Hotel Reservation System, specifically within the /admin/execeditroom.php file. The vulnerability arises from improper sanitization or validation of the 'userid' parameter, which can be manipulated by an unauthenticated remote attacker to inject malicious SQL queries. This injection flaw allows the attacker to interfere with the application's database queries, potentially leading to unauthorized data access, data modification, or even complete compromise of the backend database. The vulnerability does not require any authentication or user interaction, making it exploitable remotely with low attack complexity. Although the CVSS 4.0 base score is 6.9 (medium severity), the potential impact on confidentiality, integrity, and availability of sensitive hotel reservation data is significant. The exploit code has been publicly disclosed, increasing the risk of exploitation despite no known active exploits in the wild at the time of publication. The vulnerability affects only version 1.0 of the product, which is a web-based hotel reservation management system used by hospitality businesses to manage bookings, room details, and customer information. The lack of available patches or official mitigation guidance from the vendor increases the urgency for affected organizations to implement protective measures.

For European organizations, particularly those in the hospitality sector using the SourceCodester Online Hotel Reservation System 1.0, this vulnerability poses a substantial risk. Exploitation could lead to unauthorized disclosure of customer personal data, including booking details and possibly payment information, violating GDPR requirements and leading to regulatory penalties. Data integrity could be compromised, resulting in manipulated booking records or fraudulent reservations, which could disrupt hotel operations and damage customer trust. Availability of the reservation system could also be impacted if attackers execute destructive SQL commands, causing service outages. The reputational damage and financial losses from such incidents could be severe, especially for small to medium-sized hotels that rely heavily on this system. Additionally, since the vulnerability can be exploited remotely without authentication, attackers from anywhere could target European hospitality businesses, increasing the threat landscape. The medium CVSS score may underestimate the real-world impact given the sensitivity of the data involved and the critical role of reservation systems in business continuity.

1. Immediate isolation of any systems running SourceCodester Online Hotel Reservation System version 1.0 from public internet access until a patch or update is available. 2. Implement Web Application Firewall (WAF) rules specifically designed to detect and block SQL injection attempts targeting the 'userid' parameter in /admin/execeditroom.php. 3. Conduct a thorough audit of all web-facing hotel reservation systems to identify any instances of the vulnerable software version. 4. If source code access is available, apply manual input validation and parameterized queries or prepared statements to sanitize the 'userid' input before database interaction. 5. Monitor application logs and database logs for unusual query patterns or errors indicative of SQL injection attempts. 6. Educate IT and security teams within hospitality organizations about this specific vulnerability and the importance of rapid response. 7. Plan for migration to a more secure and actively maintained reservation system if vendor support is lacking. 8. Regularly back up reservation data and ensure backups are stored securely and tested for restoration to mitigate potential data loss from exploitation.