CVE-2025-64364 is a vulnerability identified in the StylemixThemes Masterstudy WordPress plugin, specifically affecting versions prior to 4.8.126. The issue arises from improper control over the filename parameter used in PHP include or require statements, which leads to a Local File Inclusion (LFI) vulnerability. LFI vulnerabilities allow an attacker to trick the application into including files from the local server filesystem, potentially disclosing sensitive information, executing arbitrary code, or escalating privileges. In this case, the vulnerability permits an attacker with low privileges (PR:L) to remotely include files without requiring user interaction (UI:N). The CVSS vector indicates the attack is network-based (AV:N) but requires high attack complexity (AC:H), suggesting some conditions must be met for successful exploitation. The impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H), meaning an attacker could read sensitive data, modify files or configurations, and disrupt service availability. Although no known exploits are currently reported in the wild, the vulnerability's nature and severity warrant immediate attention. The plugin is widely used in educational and e-learning WordPress sites, which often contain sensitive user data and intellectual property, increasing the risk profile. The vulnerability stems from insufficient validation or sanitization of the filename parameter before inclusion, a common PHP security flaw. Without proper patching, attackers could leverage this to execute arbitrary PHP code or access configuration files, leading to full system compromise.

For European organizations, especially those operating e-learning platforms or educational websites using the Masterstudy plugin, this vulnerability poses a significant risk. Successful exploitation could lead to unauthorized disclosure of personal data protected under GDPR, resulting in legal and financial penalties. The integrity of educational content and user data could be compromised, undermining trust and operational continuity. Availability impacts could disrupt online learning services, affecting students and staff. Given the high CVSS score and potential for full system compromise, organizations face risks including data breaches, defacement, ransomware deployment, or lateral movement within their networks. The impact is particularly critical for institutions handling sensitive student records or proprietary educational materials. Additionally, the vulnerability could be leveraged as a foothold for broader attacks targeting European educational infrastructure, which is increasingly targeted by cyber threat actors. The lack of known exploits in the wild does not diminish the urgency, as public disclosure often leads to rapid development of exploit code.

1. Immediately update the Masterstudy plugin to version 4.8.126 or later, where the vulnerability is patched. 2. If immediate patching is not possible, implement strict input validation and sanitization on all parameters that control file inclusion paths within the plugin or custom code. 3. Employ web application firewalls (WAFs) with rules designed to detect and block suspicious include/require requests or attempts to manipulate file paths. 4. Restrict PHP include paths using open_basedir directives to limit accessible directories, reducing the risk of arbitrary file inclusion. 5. Conduct thorough code reviews and security audits of customizations or integrations involving the Masterstudy plugin to identify similar insecure coding patterns. 6. Monitor logs for unusual file access patterns or errors related to file inclusion. 7. Educate development and IT teams about secure coding practices regarding file inclusion and parameter handling. 8. Maintain regular backups and incident response plans tailored to web application compromises. 9. Consider isolating or sandboxing the affected plugin environment to minimize lateral movement if exploitation occurs.