CVE-2025-46240 is a Stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79, affecting the Simple Download Counter plugin developed by Jeff Starr. This vulnerability arises from improper neutralization of user-supplied input during web page generation, allowing malicious scripts to be stored and subsequently executed in the context of users visiting affected web pages. The affected versions include all versions up to 2.2, with no specific version exclusions noted. Stored XSS vulnerabilities typically occur when input fields or parameters that accept user data fail to sanitize or encode this data properly before rendering it in HTML output. In this case, the Simple Download Counter plugin, which is commonly used to track and display download counts on websites, does not adequately sanitize input, enabling attackers to inject malicious JavaScript payloads. When other users or administrators access pages displaying the download counter, the malicious script executes in their browsers, potentially leading to session hijacking, credential theft, unauthorized actions on behalf of the user, or distribution of malware. Although no public exploits are currently known in the wild, the vulnerability's presence in a widely used plugin and the nature of stored XSS make it a significant risk if exploited. The lack of a patch or update at the time of reporting further increases exposure. Stored XSS vulnerabilities are particularly dangerous because the malicious payload persists on the server and affects multiple users without requiring repeated attacker interaction. The vulnerability does not require authentication to exploit, as it stems from user input fields that are publicly accessible or accessible to any user capable of submitting data to the plugin. This increases the attack surface and ease of exploitation. The plugin is typically deployed on WordPress websites, which are prevalent across various sectors including e-commerce, media, and corporate sites, amplifying the potential impact of this vulnerability.

For European organizations, exploitation of this stored XSS vulnerability could lead to significant confidentiality, integrity, and availability issues. Attackers could hijack user sessions, including those of administrators, leading to unauthorized access and potential takeover of websites. This could result in data breaches involving personal data protected under GDPR, exposing organizations to regulatory fines and reputational damage. Additionally, attackers could manipulate website content, deface pages, or redirect users to malicious sites, undermining trust and causing operational disruptions. The ability to execute arbitrary scripts also opens pathways for further attacks such as phishing, malware distribution, or lateral movement within the network if administrative credentials are compromised. Given the widespread use of WordPress and associated plugins in Europe, especially among small and medium enterprises (SMEs) and public sector websites, the vulnerability poses a broad risk. The lack of known exploits in the wild currently limits immediate impact, but the medium severity rating and absence of patches necessitate proactive measures to prevent exploitation. The vulnerability's exploitation does not require user interaction beyond visiting a compromised page, increasing the likelihood of successful attacks once exploited.

Organizations should immediately audit their WordPress installations to identify the presence of the Simple Download Counter plugin, particularly versions up to 2.2. Until an official patch is released, the following specific mitigations are recommended: 1) Disable or remove the Simple Download Counter plugin if it is not essential to website operations. 2) Implement Web Application Firewall (WAF) rules that specifically detect and block common XSS payload patterns targeting the plugin's input fields or output. 3) Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts on affected web pages, thereby mitigating the impact of injected scripts. 4) Sanitize and validate all user inputs at the application level, potentially through custom code or third-party plugins that enforce stricter input handling. 5) Monitor website logs and user reports for unusual activity or complaints of suspicious behavior that could indicate exploitation attempts. 6) Educate website administrators and content managers about the risks of stored XSS and encourage vigilance when reviewing user-submitted content. 7) Plan for rapid deployment of patches or updates once the vendor releases a fix, including testing in staging environments to prevent downtime. These targeted actions go beyond generic advice by focusing on the plugin-specific context and leveraging layered defenses to reduce risk.