CVE-2025-13133 identifies a CSV Injection vulnerability (CWE-1236) in the Simple User Import Export plugin for WordPress, affecting all versions up to and including 1.1.7. This vulnerability arises from improper neutralization of formula elements in CSV files generated by the plugin's import/export users functionality. Authenticated attackers with administrator-level privileges can embed malicious spreadsheet formulas into exported CSV files. When these files are opened in spreadsheet applications like Microsoft Excel or LibreOffice Calc, the formulas can execute, potentially leading to arbitrary code execution on the local system. The vulnerability exploits the way spreadsheet software interprets certain characters (e.g., '=', '+', '-', '@') at the start of CSV fields as formulas. Since the plugin does not sanitize or neutralize these inputs, malicious actors can craft payloads that trigger code execution upon file opening. The CVSS v3.1 base score is 6.6 (medium severity), reflecting network attack vector, low attack complexity, high privileges required, no user interaction, and a scope change with partial impact on confidentiality, integrity, and availability. No public exploits are currently known, but the vulnerability is published and should be remediated. The risk is particularly relevant for organizations relying on WordPress sites that use this plugin for user data management, as attackers with admin access can weaponize exported CSV files to compromise local machines of users handling these files.

For European organizations, this vulnerability poses a significant risk primarily to the confidentiality, integrity, and availability of systems where exported CSV files are handled. If malicious CSV files are opened by users on vulnerable spreadsheet software, attackers can execute arbitrary code, potentially leading to data theft, malware installation, or further network compromise. Organizations with WordPress-based websites using the Simple User Import Export plugin are at risk, especially if administrators or other privileged users export user data and open these files locally. The impact extends to sectors with high reliance on WordPress for user management, including e-commerce, education, and public administration. Given the medium CVSS score and requirement for administrator privileges, the threat is moderate but should not be underestimated. The vulnerability could be leveraged in targeted attacks or insider threat scenarios. Additionally, the CSV files might be shared or emailed internally or externally, increasing the risk of lateral movement or supply chain compromise. The lack of known exploits in the wild suggests a window for proactive mitigation before widespread exploitation occurs.

1. Immediately monitor for plugin updates from the vendor and apply patches as soon as they become available to fix the vulnerability. 2. Until a patch is released, implement input sanitization or filtering on CSV exports to neutralize formula characters ('=', '+', '-', '@') by prefixing fields with a single quote or other safe characters to prevent formula execution. 3. Educate administrators and users to treat CSV files exported from the plugin with caution, especially before opening them in spreadsheet applications. 4. Use spreadsheet software settings or security features that disable automatic formula execution or enable protected view for files originating from untrusted sources. 5. Limit administrator access strictly to trusted personnel and monitor for suspicious activity related to user import/export functions. 6. Consider alternative plugins or custom solutions that properly sanitize CSV exports if immediate patching is not feasible. 7. Employ endpoint security solutions capable of detecting and blocking malicious macro or formula execution in spreadsheet files. 8. Audit and review logs for any unusual export or file access events related to the plugin. 9. Implement network segmentation and least privilege principles to reduce the impact of potential local code execution.