CVE-2025-12674 is a critical security vulnerability found in the KiotViet Sync plugin for WordPress, affecting all versions up to and including 1.8.5. The root cause is the absence of proper file type validation in the create_media() function, which handles file uploads. This flaw allows unauthenticated attackers to upload arbitrary files to the server hosting the WordPress site. Because the plugin does not restrict or validate the file types, attackers can upload malicious files such as web shells or scripts that enable remote code execution (RCE). The vulnerability is categorized under CWE-434, which concerns unrestricted upload of files with dangerous types. The CVSS v3.1 base score is 9.8, indicating a critical severity level with attack vector network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and impacts on confidentiality, integrity, and availability all rated high (C:H/I:H/A:H). Although no known exploits have been reported in the wild yet, the vulnerability's characteristics make it highly exploitable. Attackers can leverage this to gain full control over the affected server, steal sensitive data, deface websites, or launch further attacks within the network. The plugin is widely used in WordPress environments, especially in e-commerce contexts where KiotViet Sync integrates inventory and sales data. This increases the attractiveness of targets for attackers. The lack of available patches at the time of publication necessitates immediate mitigation steps to reduce risk.

For European organizations, this vulnerability poses a severe threat to the security and operational continuity of WordPress-based websites using the KiotViet Sync plugin. Successful exploitation can lead to full server compromise, resulting in data breaches, loss of customer trust, financial damage, and potential regulatory penalties under GDPR due to unauthorized access to personal data. E-commerce businesses relying on KiotViet Sync for inventory synchronization are particularly vulnerable, as attackers could manipulate sales data or disrupt operations. The critical nature of the vulnerability means attackers can operate without authentication or user interaction, increasing the likelihood of automated exploitation attempts. This could lead to widespread infections and lateral movement within corporate networks. Additionally, compromised web servers can be used as launchpads for attacks against other organizations or to distribute malware. The impact on availability could disrupt business services, causing revenue loss and reputational harm. Given Europe's strong regulatory environment and emphasis on data protection, organizations face both operational and compliance risks if affected.

Since no official patches are available at the time of disclosure, European organizations should implement immediate compensating controls. These include disabling or uninstalling the KiotViet Sync plugin until a secure version is released. Restrict file upload permissions on the web server to prevent execution of uploaded files, such as disabling PHP execution in upload directories. Employ web application firewalls (WAFs) with rules to detect and block suspicious file upload attempts targeting the create_media() function or related endpoints. Monitor server logs and WordPress activity for unusual file uploads or access patterns. Implement strict input validation and sanitization on any custom upload functionality. Conduct regular vulnerability scans and penetration tests focusing on WordPress plugins. Educate administrators about the risks and signs of exploitation. Once a patch is released, prioritize immediate update and verify the fix. Additionally, maintain robust backups and incident response plans to recover quickly if compromise occurs. Network segmentation can limit attacker movement if exploitation happens.