CVE-2025-9703 identifies a Cross-Site Scripting (XSS) vulnerability in the Ultimate Addons for Elementor WordPress plugin (formerly Elementor Header & Footer Builder) versions before 2.5.0. The vulnerability stems from improper sanitization of SVG file contents uploaded through the xmlrpc.php endpoint using base64 encoding. SVG files can contain embedded scripts or malicious payloads, and without proper sanitization, these scripts can execute in the context of the victim's browser when the SVG is rendered. The xmlrpc.php endpoint is a WordPress feature that allows remote procedure calls, often used for remote publishing or plugin interactions. Attackers can exploit this endpoint to upload crafted SVG files that contain malicious JavaScript. When an administrator or user views the SVG, the malicious script executes, leading to XSS attacks. Such attacks can result in cookie theft, session hijacking, defacement, or pivoting to other parts of the web application. Although no public exploits have been reported yet, the vulnerability is critical due to the widespread use of the plugin and the ease of exploitation without requiring user interaction beyond viewing the malicious content. The lack of a CVSS score indicates this is a newly disclosed issue, but the CWE-79 classification confirms the nature of the vulnerability. The plugin’s failure to sanitize SVG uploads via xmlrpc.php is a significant oversight, especially given the known risks associated with SVG files. This vulnerability affects all versions prior to 2.5.0, and no patch links are currently available, suggesting users must monitor for updates or implement workarounds.

For European organizations, this vulnerability could lead to unauthorized script execution on websites using the affected plugin, compromising user sessions and potentially exposing sensitive data. Attackers could deface websites, damage brand reputation, or use compromised sites as a foothold for further attacks within corporate networks. Given the popularity of WordPress and Elementor-based plugins in Europe, especially among SMEs and digital agencies, the risk is substantial. The exploitation could affect confidentiality by stealing authentication tokens or personal data, integrity by altering website content, and availability if attackers deploy disruptive payloads. The vulnerability's exploitation does not require complex conditions, increasing the likelihood of successful attacks. Organizations relying on affected plugins for customer-facing websites or internal portals may face regulatory scrutiny under GDPR if personal data is compromised. The absence of known exploits currently provides a window for proactive mitigation, but the threat landscape could evolve rapidly once exploit code becomes available.

European organizations should immediately audit their WordPress installations to identify the use of Ultimate Addons for Elementor versions prior to 2.5.0. Until an official patch is released, consider disabling the xmlrpc.php endpoint entirely if it is not required, as this reduces the attack surface. Implement strict file upload controls to block or sanitize SVG files, possibly converting them to safer formats or using plugins that sanitize SVG content. Employ Web Application Firewalls (WAFs) with rules to detect and block malicious payloads in base64-encoded uploads. Monitor web server logs for unusual xmlrpc.php activity and base64-encoded payloads. Educate site administrators about the risks of uploading untrusted SVG files and enforce least privilege principles for user roles. Once a patch is available, prioritize immediate application. Additionally, consider implementing Content Security Policy (CSP) headers to restrict script execution contexts, mitigating the impact of potential XSS attacks. Regularly back up website data and configurations to enable rapid recovery if exploitation occurs.