CVE-2025-34246 is a SQL injection vulnerability identified in Advantech WebAccess/VPN software versions prior to 1.1.5. The flaw exists in the AjaxPrevalidationController.ajaxAction() method, which processes datatable search parameters without proper sanitization or neutralization of special SQL elements. This improper input validation allows an authenticated user with low-level observer privileges to inject arbitrary SQL commands. The injected SQL can manipulate database queries, potentially exposing sensitive information stored in the backend database. The vulnerability is remotely exploitable over the network without requiring user interaction, but it does require the attacker to have observer-level authentication credentials. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no user interaction (UI:N), and privileges required at low level (PR:L). The impact primarily affects confidentiality due to unauthorized data disclosure, with limited impact on integrity and availability. No public exploits are known at this time, but the vulnerability poses a risk especially in environments where observer accounts are widely accessible or credentials are weak. Advantech WebAccess/VPN is commonly used in industrial control systems and network management, making this vulnerability relevant for operational technology environments. The lack of a patch link suggests that a fixed version (1.1.5 or later) should be obtained directly from the vendor. Organizations should audit user roles and monitor for suspicious database query patterns to detect exploitation attempts.

For European organizations, this vulnerability can lead to unauthorized disclosure of sensitive operational and network data managed through Advantech WebAccess/VPN. This is particularly critical for industries relying on industrial control systems (ICS), manufacturing, energy, and critical infrastructure sectors prevalent in Europe. Exposure of database information can facilitate further attacks, including privilege escalation, lateral movement, or disruption of industrial processes. The medium severity rating reflects moderate risk, but the potential impact on confidentiality in sensitive environments is significant. Organizations with observer-level users who have network access to the WebAccess/VPN interface are at risk. The vulnerability could undermine trust in industrial network security and lead to regulatory compliance issues under GDPR if personal or sensitive data is exposed. Additionally, disruption or data leakage in critical infrastructure could have cascading effects on national security and economic stability in affected European countries.

1. Upgrade Advantech WebAccess/VPN to version 1.1.5 or later where the vulnerability is patched. 2. Restrict observer user privileges strictly to the minimum necessary and review account assignments regularly. 3. Implement strong authentication mechanisms and enforce complex passwords for all user roles, especially low-privileged accounts. 4. Deploy web application firewalls (WAF) with tailored rules to detect and block SQL injection attempts targeting the AjaxPrevalidationController.ajaxAction() endpoint. 5. Monitor application logs and database query logs for unusual or suspicious patterns indicative of SQL injection exploitation. 6. Conduct regular security assessments and penetration testing focused on web application inputs and authentication controls. 7. Segment network access to the WebAccess/VPN interface, limiting it to trusted hosts and networks. 8. Educate administrators and users about the risks of SQL injection and the importance of secure credential management. 9. If patching is delayed, consider disabling or restricting the vulnerable AjaxPrevalidationController.ajaxAction() functionality if feasible without disrupting operations.