CVE-2025-11345 is a deserialization vulnerability found in the Test Import component of ILIAS, an open-source web-based learning management system widely used in Europe. The vulnerability arises from unsafe use of PHP's unserialize function, which processes untrusted input without proper validation or sanitization. This flaw allows remote attackers to craft malicious serialized data that, when unserialized by the vulnerable component, can lead to arbitrary code execution or other malicious behaviors affecting confidentiality, integrity, and availability. The attack vector is remote network access with no authentication required, but user interaction is necessary, likely involving triggering the import functionality. The CVSS 4.0 base score is 5.1 (medium), reflecting the moderate impact and ease of exploitation. The vulnerability affects multiple major versions of ILIAS up to 8.23, 9.13, and 10.1, with fixed versions available at 8.24, 9.14, and 10.2. Although no known exploits have been reported in the wild, the nature of deserialization vulnerabilities makes this a significant risk if left unpatched. The flaw is particularly critical in environments where ILIAS handles sensitive educational or personal data, as exploitation could lead to data leakage, unauthorized access, or service disruption.

For European organizations, especially universities, schools, and government agencies relying on ILIAS for e-learning and training, this vulnerability poses a risk of unauthorized code execution or data compromise. Exploitation could lead to leakage of sensitive student or employee information, manipulation of learning content, or disruption of educational services. Given ILIAS’s strong presence in German-speaking countries and other parts of Europe, the impact could be widespread. The medium severity score indicates moderate risk, but the ease of remote exploitation without authentication increases urgency. Organizations may face compliance and reputational risks if sensitive data is exposed or services are interrupted. Attackers could leverage this vulnerability to establish footholds within networks or pivot to other systems, amplifying the threat.

1. Immediately upgrade ILIAS installations to versions 8.24, 9.14, or 10.2 or later, which contain the patch for this vulnerability. 2. Restrict access to the Test Import component to trusted administrators only, using network segmentation and access controls. 3. Implement web application firewalls (WAFs) with rules to detect and block suspicious serialized payloads targeting the unserialize function. 4. Monitor application logs and network traffic for unusual activity related to import operations or deserialization attempts. 5. Conduct security awareness training for administrators to recognize and avoid triggering malicious import files. 6. Regularly audit and update all third-party components and dependencies within ILIAS to reduce attack surface. 7. Consider deploying runtime application self-protection (RASP) tools that can detect and prevent unsafe deserialization at runtime. 8. Establish incident response plans specific to LMS platforms to quickly contain and remediate any exploitation attempts.