CVE-2025-13048 is a stored Cross-Site Scripting (XSS) vulnerability identified in the StatCounter – Free Real Time Visitor Stats plugin for WordPress, affecting all versions up to and including 2.1.0. The vulnerability stems from improper neutralization of input during web page generation (CWE-79), specifically insufficient sanitization and output escaping of the user's Nickname field. Authenticated attackers with Contributor-level privileges or higher can exploit this flaw by injecting arbitrary JavaScript code into the Nickname field. This malicious script is then stored persistently and executed in the context of any user who accesses the infected page, including administrators and other privileged users. The attack vector is remote network-based, with low complexity and no requirement for user interaction, but it does require authentication at the Contributor level or above. The vulnerability impacts confidentiality and integrity by enabling session hijacking, credential theft, or unauthorized actions performed on behalf of users. Availability is not directly affected. The vulnerability has a CVSS 3.1 score of 6.4, reflecting medium severity. No public exploits have been reported yet, but the presence of this vulnerability in a widely used WordPress plugin makes it a significant concern. The lack of available patches at the time of reporting necessitates immediate mitigation efforts by administrators. The vulnerability highlights the importance of proper input validation and output encoding in web applications, especially in user-generated content fields. Organizations relying on this plugin should audit user roles and permissions, restrict Contributor-level access, and monitor for anomalous script execution or unexpected behavior on their WordPress sites.

For European organizations, this vulnerability poses a moderate risk primarily to websites using the StatCounter plugin on WordPress platforms. Exploitation could lead to unauthorized script execution, resulting in session hijacking, theft of sensitive user information, and potential privilege escalation within the affected websites. This can compromise the integrity and confidentiality of data, damage organizational reputation, and lead to regulatory compliance issues under GDPR if personal data is exposed. Since the attack requires authenticated access at Contributor level or above, organizations with lax user access controls are at higher risk. The widespread use of WordPress in Europe, especially among SMEs and digital service providers, increases the potential attack surface. Additionally, sectors with high reliance on web presence such as e-commerce, media, and public services could face operational disruptions or data breaches. While availability is not directly impacted, the indirect effects of compromised administrative accounts or defacement could cause downtime or loss of customer trust. The absence of known exploits currently limits immediate widespread impact but does not diminish the urgency for mitigation given the ease of exploitation and potential consequences.

1. Immediately review and restrict user roles on WordPress sites using the StatCounter plugin, limiting Contributor-level access to trusted users only. 2. Implement strict input validation and output encoding on all user-generated content fields, especially the Nickname field, to prevent injection of malicious scripts. 3. Monitor logs and user activity for unusual behavior indicative of XSS exploitation attempts or unauthorized script execution. 4. If possible, temporarily disable or remove the StatCounter plugin until a security patch is released. 5. Educate site administrators and content contributors about the risks of XSS and safe content practices. 6. Employ Web Application Firewalls (WAFs) configured to detect and block XSS payloads targeting the affected plugin. 7. Regularly update WordPress core, plugins, and themes to incorporate security fixes promptly. 8. Conduct security audits and penetration testing focusing on user input handling and privilege escalation vectors. 9. Consider implementing Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts. 10. Prepare incident response plans to quickly address potential exploitation events.