CVE-2025-13133 is a vulnerability classified under CWE-1236 (Improper Neutralization of Formula Elements in a CSV File) affecting the Simple User Import Export plugin for WordPress, developed by vaniivan. This plugin facilitates bulk import and export of user data in CSV format. The vulnerability exists in all versions up to and including 1.1.7 and arises because the plugin fails to properly sanitize or neutralize untrusted input embedded into CSV files during export. Specifically, an authenticated attacker with administrator privileges can craft malicious input containing spreadsheet formula elements (e.g., starting with '=', '+', '-', or '@') that are embedded into the exported CSV. When a legitimate user downloads and opens this CSV file in spreadsheet software such as Microsoft Excel or LibreOffice Calc, these formulas can execute, potentially running arbitrary commands or scripts on the local machine. This can lead to code execution, data leakage, or further compromise of the user's environment. The attack requires high privileges (administrator access) and no user interaction beyond opening the file, but the scope is limited to users who handle these CSV exports. The CVSS v3.1 base score is 6.6, indicating a medium severity with network attack vector, low attack complexity, high privileges required, no user interaction, and a scope change affecting confidentiality, integrity, and availability at a limited level. No patches or known exploits are currently reported, but the vulnerability is publicly disclosed and should be addressed promptly.

For European organizations, the impact of CVE-2025-13133 can be significant, especially for those relying on the Simple User Import Export plugin for managing WordPress user data. Successful exploitation could allow attackers with administrator access to execute arbitrary code on the local machines of users who open the exported CSV files, potentially leading to data theft, malware installation, or lateral movement within the network. This risk is heightened in environments where exported CSV files are shared across departments or with third parties, increasing the attack surface. Confidentiality, integrity, and availability of user data and systems can be compromised. Given the requirement for administrator privileges, the threat primarily concerns insider threats or attackers who have already gained elevated access. The vulnerability could also be leveraged as part of a multi-stage attack chain. European organizations in sectors with high WordPress usage, such as media, education, and small to medium enterprises, may face increased risk. Additionally, regulatory frameworks like GDPR impose strict data protection requirements, and exploitation leading to data breaches could result in legal and financial penalties.

To mitigate CVE-2025-13133, European organizations should take the following specific actions: 1) Immediately update the Simple User Import Export plugin to a patched version once available; if no patch is currently released, consider temporarily disabling the import/export functionality to prevent exploitation. 2) Implement strict access controls to limit administrator privileges only to trusted personnel and monitor for unusual administrative activities. 3) Educate users who handle CSV exports about the risks of opening files from untrusted sources and encourage opening CSV files in spreadsheet applications with formula execution disabled or in safe modes. 4) Employ endpoint protection solutions that can detect and block suspicious macro or formula execution in spreadsheet software. 5) Sanitize and validate all user inputs before exporting to CSV, possibly by escaping or prefixing formula characters to neutralize them. 6) Monitor logs and audit trails for signs of exploitation attempts or anomalous CSV file generation. 7) Consider alternative user import/export tools with better security track records if patching is delayed. These targeted measures go beyond generic advice by focusing on controlling privilege, user behavior, and input sanitization specific to this vulnerability.