CVE-2025-63617 identifies a deserialization vulnerability in the ktg-mes software prior to commit a484f96 dated July 3, 2025. The root cause is the inclusion of a vulnerable version of the fastjson library, which is known to have unsafe deserialization behavior. Deserialization vulnerabilities arise when untrusted input is parsed into objects without sufficient validation or filtering, allowing attackers to craft malicious payloads that can manipulate program state or leak sensitive data. In this case, the vulnerability is classified under CWE-502 (Deserialization of Untrusted Data). The CVSS 3.1 base score is 6.5, indicating a medium severity issue with the following vector metrics: Attack Vector Network (AV:N), Attack Complexity Low (AC:L), Privileges Required None (PR:N), User Interaction None (UI:N), Scope Unchanged (S:U), Confidentiality Low (C:L), Integrity Low (I:L), and Availability None (A:N). This means an attacker can remotely exploit the vulnerability without authentication or user interaction, potentially causing limited confidentiality and integrity impacts, such as unauthorized data access or modification. No patches or exploit code are currently publicly available, and no known exploits in the wild have been reported. The vulnerability affects all versions of ktg-mes before the specified commit, but exact version numbers are not provided. Fastjson is a widely used JSON parsing library in Java environments, often employed in enterprise applications including manufacturing execution systems (MES) like ktg-mes. The unsafe deserialization can be triggered by sending specially crafted JSON payloads to the vulnerable component, which then processes the input and deserializes it into Java objects, potentially leading to data leakage or manipulation. Given the nature of MES software, which often integrates with critical industrial control systems and production data, exploitation could disrupt manufacturing processes or expose sensitive operational data.

For European organizations, especially those in manufacturing and industrial sectors using ktg-mes or similar MES solutions incorporating fastjson, this vulnerability poses a risk of unauthorized data access and integrity compromise. While the availability impact is none, confidentiality and integrity impacts could lead to leakage of sensitive production data or unauthorized alteration of manufacturing parameters. This could result in intellectual property theft, production errors, or compliance violations under regulations like GDPR if personal or sensitive data is involved. The ease of exploitation (no authentication or user interaction required) increases the threat level, particularly for organizations exposing MES interfaces to untrusted networks or insufficiently segmented environments. Although no known exploits exist yet, the widespread use of fastjson and the critical nature of MES systems make this a significant concern. Attackers targeting European industrial infrastructure could leverage this vulnerability to gain footholds or conduct espionage. The medium severity rating reflects these factors but also the limited scope of impact compared to more critical vulnerabilities.

To mitigate CVE-2025-63617, European organizations should first identify all instances of ktg-mes and verify the version of fastjson in use. Immediate steps include upgrading fastjson to the latest patched version that addresses deserialization vulnerabilities. If an upgrade is not immediately feasible, implement strict input validation and sanitization on all JSON inputs processed by ktg-mes to block malicious payloads. Employ network segmentation and firewall rules to restrict access to MES interfaces, limiting exposure to trusted internal networks only. Monitor logs for unusual deserialization activity or malformed JSON inputs indicative of exploitation attempts. Consider deploying Web Application Firewalls (WAFs) with custom rules to detect and block suspicious deserialization patterns. Conduct thorough security assessments and penetration testing focused on deserialization attack vectors. Finally, maintain an incident response plan tailored to industrial control systems to quickly respond to any exploitation attempts.