The vulnerability identified as CVE-2025-13314 affects the WordPress plugin 'Product Filtering by Categories, Tags, Price Range for WooCommerce – Filter Plus' developed by markutos987. This plugin is widely used to enhance WooCommerce stores by providing advanced product filtering capabilities. The root cause of the vulnerability is a missing authorization check (CWE-862) on two AJAX endpoints: 'filter_save_settings' and 'add_filter_options'. These endpoints handle requests to save plugin settings and add new filter options, respectively. Because the plugin fails to verify whether the requester has the necessary permissions, unauthenticated attackers can invoke these AJAX actions remotely without any credentials or user interaction. This allows attackers to modify the plugin’s configuration arbitrarily, potentially injecting malicious or misleading filter options that could alter the shopping experience or be leveraged for further exploitation. The vulnerability affects all versions up to 1.1.5, and no patches are currently linked, indicating that users must be vigilant. The CVSS v3.1 score is 5.3 (medium severity), reflecting the lack of confidentiality or availability impact but acknowledging the integrity compromise and ease of exploitation. Although no known exploits are reported in the wild, the vulnerability’s presence in a popular e-commerce plugin makes it a significant risk for WooCommerce-based online stores.

For European organizations operating WooCommerce-based e-commerce platforms, this vulnerability poses a risk of unauthorized modification of product filtering settings. Such unauthorized changes can degrade user experience by presenting incorrect or manipulated product filters, potentially leading to loss of customer trust and revenue. Additionally, attackers could use this foothold to insert misleading filters that redirect customers to malicious products or phishing pages if combined with other vulnerabilities. While the vulnerability does not directly expose sensitive data or cause service outages, the integrity compromise can facilitate further attacks or fraud. Given the widespread use of WooCommerce in Europe, especially among small and medium-sized enterprises, the threat could have broad implications. Regulatory compliance under GDPR may also be impacted if the altered filters lead to unauthorized data processing or misrepresentation of product information. The absence of known exploits reduces immediate risk but does not eliminate the potential for future attacks.

European organizations should immediately verify if their WooCommerce installations use the 'Product Filtering by Categories, Tags, Price Range for WooCommerce – Filter Plus' plugin at version 1.1.5 or earlier. Since no official patch links are provided, users should monitor the vendor’s channels for updates or consider disabling the plugin temporarily to prevent exploitation. As a practical mitigation, implement Web Application Firewall (WAF) rules to block unauthorized access to the vulnerable AJAX endpoints ('filter_save_settings' and 'add_filter_options'), restricting these actions to authenticated and authorized users only. Additionally, review and harden WordPress user roles and permissions to minimize exposure. Regularly audit plugin configurations and monitor logs for suspicious AJAX requests. Organizations should also consider alternative, more secure filtering plugins if immediate patching is not feasible. Finally, maintain up-to-date backups to enable recovery if unauthorized changes occur.