The vulnerability CVE-2025-11170 affects the kddiwebcommunications WP移行専用プラグイン for CPI, a WordPress plugin designed for migration purposes. The core issue lies in the Cpiwm_Import_Controller::import function, which lacks proper validation of uploaded file types. This absence of validation allows unauthenticated attackers to upload arbitrary files, including potentially malicious scripts, to the server hosting the WordPress site. Once uploaded, these files could be executed remotely, leading to full compromise of the web server, including data theft, defacement, or pivoting to internal networks. The vulnerability is categorized under CWE-434, which concerns unrestricted file uploads that can lead to dangerous consequences. The CVSS 3.1 score of 9.8 reflects the vulnerability's critical nature: it can be exploited remotely over the network without any authentication or user interaction, and it impacts confidentiality, integrity, and availability severely. Although no public exploits have been observed yet, the straightforward exploitation path and the critical impact make this a high-risk vulnerability. The plugin affects all versions up to and including 1.0.2, and no patches are currently linked, indicating that users must be vigilant and consider temporary mitigations. The vulnerability was reserved in late September 2025 and published in November 2025, suggesting recent discovery and disclosure. This vulnerability is particularly dangerous because WordPress is widely used, and plugins often have elevated privileges, increasing the attack surface. The lack of file type validation is a common but critical security oversight that can be exploited to upload web shells or other malicious payloads.

For European organizations, the impact of CVE-2025-11170 is significant. Many businesses, government agencies, and institutions in Europe rely on WordPress for their websites and digital services. A successful exploitation could lead to unauthorized access to sensitive data, defacement of public-facing websites, disruption of services, and potential lateral movement within internal networks. This could result in reputational damage, regulatory penalties under GDPR for data breaches, and operational downtime. Sectors such as finance, healthcare, education, and public administration are particularly vulnerable due to the sensitive nature of their data and the criticality of their services. The ability to execute remote code without authentication means attackers can compromise systems at scale and with relative ease. Additionally, the lack of known exploits currently does not reduce the urgency, as proof-of-concept code could emerge rapidly following disclosure, increasing the risk of widespread attacks. The vulnerability could also be leveraged by cybercriminal groups or state-sponsored actors targeting European digital infrastructure.

European organizations should immediately audit their WordPress environments to identify installations of the WP移行専用プラグイン for CPI plugin. Until an official patch is released, organizations should consider disabling or uninstalling the plugin if it is not essential. If the plugin is required, implement strict file upload restrictions at the web server or application firewall level to block dangerous file types such as PHP, ASP, or other executable scripts. Employ web application firewalls (WAFs) with custom rules to detect and block suspicious upload attempts. Monitor web server logs for unusual file uploads or access patterns. Restrict permissions on upload directories to prevent execution of uploaded files. Regularly update WordPress core and all plugins to the latest versions once patches become available. Conduct penetration testing focused on file upload functionalities to detect similar vulnerabilities. Additionally, implement network segmentation to limit the impact of a potential compromise and maintain robust backup and incident response plans to recover quickly from any exploitation.