CVE-2025-49401 is a critical security vulnerability classified under CWE-502, which involves the deserialization of untrusted data in the ExpressTech Systems product 'Quiz And Survey Master'. This vulnerability allows for object injection attacks, where an attacker can craft malicious serialized objects that, when deserialized by the application, can lead to arbitrary code execution or other malicious outcomes. The affected versions include all versions up to 10.2.5, with no specific lower bound version identified. The vulnerability has a CVSS 3.1 base score of 9.8, indicating a critical severity level. The vector details (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H) reveal that the attack can be executed remotely over the network without any privileges or user interaction, and it impacts confidentiality, integrity, and availability to a high degree. The root cause is insecure deserialization, a common issue where the application accepts serialized objects from untrusted sources and deserializes them without proper validation or sanitization. This can lead to object injection, enabling attackers to manipulate application logic, execute arbitrary code, or cause denial of service. Although no known exploits are currently reported in the wild, the critical nature and ease of exploitation make this a significant threat. The absence of patch links suggests that a fix may not yet be publicly available, increasing the urgency for mitigation measures.

For European organizations using ExpressTech Systems' Quiz And Survey Master plugin, this vulnerability poses a severe risk. Given the plugin's role in managing quizzes and surveys, often integrated into websites and learning management systems, exploitation could lead to full system compromise. Attackers could steal sensitive user data, manipulate survey results, or disrupt service availability, impacting organizational reputation and compliance with data protection regulations such as GDPR. The ability to execute code remotely without authentication means attackers can pivot into broader network environments, potentially accessing other critical systems. This is particularly concerning for sectors like education, government, and enterprises relying on this plugin for user engagement and data collection. The critical severity and lack of patches increase the risk window, necessitating immediate attention to prevent data breaches, service outages, and regulatory penalties.

1. Immediate mitigation should include disabling or removing the Quiz And Survey Master plugin from production environments until a patch is available. 2. Implement strict input validation and sanitization on any serialized data inputs if custom deserialization logic exists. 3. Employ web application firewalls (WAFs) with rules designed to detect and block malicious serialized payloads targeting this vulnerability. 4. Monitor network traffic and application logs for unusual deserialization activity or anomalies indicative of exploitation attempts. 5. Restrict network exposure of systems running the vulnerable plugin, limiting access to trusted IP ranges only. 6. Stay updated with ExpressTech Systems' advisories and apply official patches immediately upon release. 7. Conduct security audits and penetration testing focusing on deserialization vulnerabilities in related applications. 8. Consider implementing runtime application self-protection (RASP) solutions to detect and prevent exploitation in real time.