CVE-2025-56385 is a critical SQL injection vulnerability identified in WellSky Harmony version 4.1.0.2.83, specifically within the 'xmHarmony.asp' endpoint's login functionality. The vulnerability stems from the failure to properly sanitize user input supplied to the 'TXTUSERID' parameter before it is incorporated into SQL queries. This flaw allows an unauthenticated attacker to inject arbitrary SQL commands directly into the backend database query. Given the nature of the login endpoint, successful exploitation can lead to authentication bypass, enabling attackers to gain unauthorized access without valid credentials. Furthermore, attackers can exfiltrate sensitive data, modify or delete records, and potentially execute administrative commands on the database server, resulting in full system compromise. The vulnerability has a CVSS v3.1 base score of 9.8, indicating critical severity with network attack vector, no required privileges or user interaction, and high impact on confidentiality, integrity, and availability. Although no public exploits have been reported yet, the simplicity of exploitation and the critical nature of the affected system make it a high-risk threat. WellSky Harmony is widely used in healthcare and social service management, meaning that exploitation could expose sensitive patient and organizational data, disrupt critical services, and cause regulatory compliance violations. The lack of available patches at the time of disclosure increases the urgency for organizations to implement interim mitigations and monitor for suspicious activity.

For European organizations, the impact of CVE-2025-56385 is substantial, particularly for those in healthcare, social services, and related sectors relying on WellSky Harmony for patient and case management. Exploitation could lead to unauthorized access to sensitive personal and health data, violating GDPR and other data protection regulations, resulting in legal penalties and reputational damage. The ability to bypass authentication and manipulate backend databases threatens operational continuity, potentially disrupting critical care services and administrative functions. Data integrity loss could affect patient treatment records, leading to medical errors. Availability impacts could result from destructive SQL commands or ransomware deployment following initial compromise. The critical nature of this vulnerability demands urgent attention to prevent data breaches and service outages that could affect vulnerable populations and critical infrastructure within Europe.

Given the absence of an official patch, European organizations should immediately implement the following mitigations: 1) Employ Web Application Firewalls (WAFs) with custom rules to detect and block SQL injection attempts targeting the 'TXTUSERID' parameter and the 'xmHarmony.asp' endpoint. 2) Conduct thorough input validation and sanitization on all user-supplied data at the application layer, if possible through configuration or temporary code fixes. 3) Restrict database user permissions to the minimum necessary, avoiding use of high-privilege accounts for application access to limit potential damage. 4) Monitor logs and network traffic for unusual queries or authentication bypass attempts, enabling rapid detection of exploitation attempts. 5) Isolate the WellSky Harmony application server within segmented network zones to reduce lateral movement risk. 6) Prepare incident response plans specific to database compromise scenarios. 7) Engage with WellSky support and subscribe to security advisories to apply official patches immediately upon release. 8) Consider temporary alternative authentication mechanisms or additional multi-factor authentication layers to mitigate authentication bypass risks.