CVE-2025-9705 is a SQL Injection vulnerability identified in version 1.0 of the SourceCodester Water Billing System, specifically in the /paybill.php file. The vulnerability arises due to improper sanitization or validation of the 'ID' parameter, which allows an attacker to manipulate SQL queries executed by the application. This flaw enables remote attackers to inject arbitrary SQL code without requiring authentication or user interaction, potentially leading to unauthorized data access, data modification, or disruption of service. The vulnerability has a CVSS 4.0 base score of 6.9, indicating a medium severity level. The vector details (AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L) show that the attack can be performed remotely over the network with low attack complexity, no privileges, and no user interaction required. The impact on confidentiality, integrity, and availability is limited but present, as the injection can lead to partial data disclosure or modification. No official patches or mitigations have been published yet, and while no known exploits are currently active in the wild, a public exploit is available, increasing the risk of exploitation.

For European organizations using the SourceCodester Water Billing System 1.0, this vulnerability poses a significant risk to the confidentiality and integrity of billing data. Water utilities and municipal services that rely on this software could face unauthorized access to customer billing information, manipulation of billing records, or disruption of billing operations. Such compromises could lead to financial losses, erosion of customer trust, regulatory penalties under GDPR for data breaches, and operational downtime. Given the critical nature of water billing services, exploitation could also indirectly affect service delivery and public trust in municipal infrastructure. The fact that the vulnerability can be exploited remotely without authentication increases the attack surface and the urgency for mitigation.

Organizations should immediately audit their use of the SourceCodester Water Billing System, specifically verifying if version 1.0 is in use. Since no official patch is currently available, immediate mitigations include implementing web application firewall (WAF) rules to detect and block SQL injection patterns targeting the /paybill.php endpoint and the 'ID' parameter. Input validation and parameterized queries should be enforced at the application level to prevent injection. Network segmentation can limit exposure of the billing system to trusted internal networks only. Monitoring logs for unusual database queries or access patterns is critical to detect exploitation attempts. Organizations should also prepare for an upgrade path or vendor patch once available and consider alternative billing solutions if remediation is delayed. Regular backups of billing data should be maintained to enable recovery in case of data tampering.