CVE-2025-8289 is a high-severity vulnerability affecting the 'Redirection for Contact Form 7' WordPress plugin developed by themeisle. The vulnerability arises from unsafe deserialization of untrusted data (CWE-502) in the delete_associated_files function, which allows unauthenticated attackers to perform PHP Object Injection (POI). This vulnerability is present in all versions up to and including 3.2.4. Exploitation requires that the vulnerable plugin is installed alongside the 'Redirection For Contact Form 7 Extension - Create Post' extension and that the site has a form with a file upload action. Additionally, the vulnerability does not affect sites running PHP versions greater than 8. The core issue is that the plugin deserializes user-supplied input without proper validation, enabling attackers to inject crafted PHP objects. However, the vulnerability alone does not guarantee exploitation because no proof-of-concept (POP) gadget chain is present within the vulnerable plugin itself. Exploitation depends on the presence of additional plugins or themes that contain a POP chain, which can be leveraged to achieve arbitrary file deletion, sensitive data disclosure, or remote code execution. Notably, the Contact Form 7 plugin, which is a prerequisite for this plugin, contains a usable gadget that enables arbitrary file deletion when combined with the vulnerable plugin and the extension. The vulnerability has a CVSS v3.1 base score of 7.5 (high), reflecting its network attack vector, high impact on confidentiality, integrity, and availability, but requiring high attack complexity and user interaction. No known exploits are currently observed in the wild. The vulnerability is significant because Contact Form 7 is one of the most widely used WordPress form plugins, and many sites use the Redirection for Contact Form 7 plugin and its extensions to enhance form functionality. This creates a potentially large attack surface, especially for sites running PHP versions 7.x or lower and having the extension enabled. In summary, CVE-2025-8289 is a deserialization vulnerability that can lead to severe consequences such as arbitrary file deletion and potentially remote code execution, contingent on the presence of additional vulnerable components. It highlights the risks of unsafe deserialization in WordPress plugins and the importance of maintaining updated PHP versions and plugin ecosystems.

For European organizations, this vulnerability poses a significant risk, especially for those relying on WordPress websites with Contact Form 7 and the Redirection for Contact Form 7 plugin and its 'Create Post' extension enabled. The potential impacts include unauthorized deletion of critical files, exposure of sensitive data, and possible remote code execution, which can lead to website defacement, data breaches, service disruption, and reputational damage. Given the widespread use of WordPress in Europe for corporate, governmental, and e-commerce websites, exploitation could disrupt business operations and compromise customer data, potentially violating GDPR requirements. The requirement for user interaction and high attack complexity somewhat limits mass exploitation, but targeted attacks against high-value European entities remain a concern. Furthermore, organizations running PHP versions below 8 are at greater risk, as the vulnerability does not affect PHP 8 and above. The absence of known exploits in the wild currently reduces immediate risk, but the presence of a confirmed gadget chain in Contact Form 7 increases the likelihood of future exploit development. Overall, the vulnerability could facilitate lateral movement or privilege escalation within compromised web environments, amplifying its impact on European organizations.

1. Upgrade PHP to version 8 or higher on all WordPress hosting environments, as the vulnerability does not affect PHP versions above 8. 2. Update or disable the 'Redirection for Contact Form 7' plugin and its 'Create Post' extension until a patched version is released. If no patch is available, consider removing these plugins to eliminate exposure. 3. Audit all installed plugins and themes for known POP chains that could be leveraged in conjunction with this vulnerability, and update or remove vulnerable components. 4. Implement strict input validation and sanitization for all file upload forms to minimize the risk of malicious payloads. 5. Employ Web Application Firewalls (WAFs) with rules targeting deserialization attacks and PHP Object Injection patterns to detect and block exploitation attempts. 6. Monitor web server and application logs for unusual activity related to file deletions or suspicious serialized data submissions. 7. Restrict file system permissions for the WordPress installation to limit the impact of arbitrary file deletion. 8. Regularly back up website data and files to enable rapid recovery in case of successful exploitation. 9. Educate site administrators about the risks of installing unverified plugins and extensions, emphasizing the importance of timely updates and security reviews.