CVE-2025-11105 is a SQL Injection vulnerability identified in version 1.0 of the code-projects Simple Scheduling System, specifically within the /schedulingsystem/addsubject.php file. The vulnerability arises due to improper sanitization or validation of the 'subcode' parameter, which allows an attacker to inject malicious SQL code. This flaw enables remote attackers to manipulate backend database queries without requiring authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:L/AT:N/PR:N/UI:N). The vulnerability impacts the confidentiality, integrity, and availability of the affected system's data, as attackers could potentially extract sensitive information, modify database contents, or disrupt service availability. Although the CVSS score is 6.9 (medium severity), the exploitability is relatively straightforward given the lack of required privileges and user interaction. No official patches or mitigations have been published yet, and while no known exploits are currently observed in the wild, the existence of a public exploit increases the risk of exploitation. The vulnerability is limited to version 1.0 of the Simple Scheduling System, which is a niche scheduling software product, but the impact on affected deployments can be significant due to the nature of SQL injection attacks.

For European organizations using the Simple Scheduling System 1.0, this vulnerability poses a moderate risk. Exploitation could lead to unauthorized access to scheduling data, potentially exposing sensitive organizational information such as personnel schedules, project timelines, or resource allocations. This could result in operational disruptions, data breaches, or reputational damage. Given the remote and unauthenticated nature of the attack, threat actors could exploit this vulnerability to gain a foothold within the network or escalate privileges by manipulating database contents. The impact is particularly relevant for sectors relying heavily on scheduling systems, such as education, healthcare, and manufacturing. Additionally, GDPR considerations mean that any data breach resulting from exploitation could lead to regulatory penalties and legal consequences for European entities.

Immediate mitigation should focus on implementing input validation and parameterized queries or prepared statements to prevent SQL injection in the affected 'subcode' parameter. Organizations should audit their use of the Simple Scheduling System 1.0 and restrict external access to the scheduling system, ideally placing it behind firewalls or VPNs to limit exposure. Monitoring and logging database queries and web application activity can help detect suspicious behavior indicative of exploitation attempts. Since no official patch is currently available, organizations should consider upgrading to a newer, unaffected version if available or applying custom fixes to sanitize inputs. Additionally, conducting a thorough security review of all web-facing applications and educating developers on secure coding practices will reduce the risk of similar vulnerabilities. Finally, organizations should prepare incident response plans to quickly address potential exploitation.