CVE-2025-9704 is a SQL Injection vulnerability identified in version 1.0 of the SourceCodester Water Billing System, specifically affecting the /viewbill.php file. The vulnerability arises from improper sanitization or validation of the 'ID' parameter, which can be manipulated by an attacker to inject malicious SQL code. This flaw allows an unauthenticated remote attacker to execute arbitrary SQL queries against the backend database. The exploit does not require any user interaction or authentication, making it highly accessible for attackers. The CVSS 4.0 base score of 6.9 (medium severity) reflects that the attack vector is network-based with low attack complexity and no privileges or user interaction required. The impact on confidentiality, integrity, and availability is limited but present, as the vulnerability allows partial compromise of data (VC:L, VI:L, VA:L). Although no known exploits are currently reported in the wild, the public availability of the exploit code increases the risk of exploitation. The vulnerability could lead to unauthorized data disclosure, data modification, or disruption of billing operations, depending on the database queries executed by the attacker. Given the critical role of water billing systems in municipal infrastructure, exploitation could have operational and reputational consequences for affected organizations.

For European organizations, the exploitation of this SQL Injection vulnerability in water billing systems could lead to unauthorized access to sensitive customer billing data, including personal and financial information. This breach of confidentiality could result in privacy violations under GDPR, leading to regulatory penalties and loss of customer trust. Integrity of billing data could be compromised, causing incorrect billing, financial losses, or disputes. Availability impacts, while limited, could disrupt billing services temporarily, affecting revenue and customer service. Municipal utilities and private water service providers using this software are at risk of operational disruptions. Additionally, attackers could leverage the vulnerability as a foothold for further network intrusion or lateral movement within critical infrastructure environments. The public availability of the exploit increases the urgency for European organizations to address this vulnerability promptly to avoid potential data breaches and service interruptions.

1. Immediate application of patches or updates from the vendor once available is critical. Since no patch links are currently provided, organizations should monitor SourceCodester announcements closely. 2. In the interim, implement web application firewall (WAF) rules specifically designed to detect and block SQL Injection attempts targeting the 'ID' parameter in /viewbill.php. 3. Conduct thorough input validation and parameterized query implementation in the affected code to prevent injection. If source code access is available, refactor the vulnerable function to use prepared statements or stored procedures. 4. Restrict database user permissions to the minimum necessary to limit the impact of any successful injection. 5. Monitor logs for unusual database queries or access patterns indicative of exploitation attempts. 6. Perform regular security assessments and penetration testing focusing on web application vulnerabilities. 7. Educate IT and security teams about the vulnerability and ensure incident response plans include steps for SQL Injection incidents. 8. Consider network segmentation to isolate the water billing system from other critical infrastructure to reduce lateral movement risk.