CVE-2025-3814 is a Stored Cross-Site Scripting (XSS) vulnerability affecting the Tax Switch for WooCommerce plugin developed by wijnbergdevelopments. This plugin is used within WordPress environments to manage tax configurations in WooCommerce-based e-commerce sites. The vulnerability arises from improper neutralization of input during web page generation, specifically via the 'class-name' parameter. Versions up to and including 1.4.2 are affected, with no patch currently available. The root cause is insufficient input sanitization and output escaping, allowing an authenticated attacker with Contributor-level access or higher to inject arbitrary JavaScript code into pages. These malicious scripts are stored persistently and execute whenever any user accesses the compromised page. This can lead to session hijacking, defacement, redirection to malicious sites, or other malicious activities leveraging the victim’s browser context. Exploitation requires authentication at the Contributor level or above, which means the attacker must have some level of trusted access to the WordPress backend, but does not require administrator privileges. No known exploits are currently reported in the wild. The vulnerability is classified under CWE-79, highlighting the failure to properly sanitize inputs that are later rendered in web pages. The plugin’s widespread use in WooCommerce stores makes this a significant vector for targeted attacks against e-commerce platforms, especially those relying on this plugin for tax management. The lack of a patch and the persistent nature of the XSS increase the risk of prolonged compromise if exploited.

For European organizations, this vulnerability poses a moderate but tangible risk, particularly for small to medium-sized enterprises (SMEs) and online retailers using WooCommerce with the Tax Switch plugin. Successful exploitation could lead to theft of user credentials, session tokens, or other sensitive information, enabling further compromise of user accounts or administrative functions. It could also facilitate phishing attacks by injecting malicious content into trusted e-commerce sites, damaging brand reputation and customer trust. Given the GDPR framework, any data breach resulting from such an attack could lead to regulatory penalties and mandatory breach notifications. The persistent nature of the stored XSS means that multiple users, including customers and administrators, could be affected over time, amplifying the impact. Additionally, attackers could leverage this vulnerability as a foothold to escalate privileges or pivot within the compromised environment. While the requirement for Contributor-level access limits the attack surface, insider threats or compromised lower-privilege accounts could be exploited. The absence of known exploits suggests the threat is currently low but could increase rapidly once exploit code becomes publicly available.

1. Immediate mitigation should focus on restricting Contributor-level access to trusted users only, implementing strict user role management and monitoring for unusual activity. 2. Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious payloads targeting the 'class-name' parameter or other input vectors in the Tax Switch plugin. 3. Conduct thorough audits of all user-generated content and plugin settings to identify and remove any injected scripts. 4. Encourage the plugin vendor to release a patch promptly; meanwhile, consider disabling or replacing the Tax Switch plugin if feasible. 5. Implement Content Security Policy (CSP) headers to limit the execution of unauthorized scripts on affected sites. 6. Regularly update WordPress core, WooCommerce, and all plugins to the latest versions to reduce exposure to known vulnerabilities. 7. Educate site administrators and contributors on secure input handling and the risks of XSS to minimize inadvertent exposure. 8. Monitor logs and user activity for signs of exploitation attempts, especially focusing on Contributor-level accounts. 9. For organizations with high security requirements, consider isolating e-commerce environments or deploying additional endpoint protections to detect anomalous script execution.