CVE-2025-53570 is a Stored Cross-Site Scripting (XSS) vulnerability classified under CWE-79, affecting the DELUCKS SEO plugin up to version 2.7.0. Stored XSS occurs when malicious input is improperly neutralized and then permanently stored by the application, later served to users without adequate sanitization or encoding. In this case, the DELUCKS SEO plugin fails to properly sanitize user-supplied input during web page generation, allowing attackers to inject malicious scripts that execute in the context of other users' browsers. The vulnerability requires low attack complexity (AC:L) but does require privileges (PR:L) and user interaction (UI:R), indicating that an attacker with some level of authenticated access can craft payloads that, when viewed by other users, execute malicious JavaScript. The CVSS v3.1 base score is 6.5 (medium severity), reflecting limited confidentiality, integrity, and availability impacts but a significant risk of session hijacking, credential theft, or unauthorized actions performed on behalf of users due to the cross-site scripting. The vulnerability has not yet been exploited in the wild, and no patches have been published at the time of disclosure. The scope is changed (S:C), meaning the vulnerability affects components beyond the initially vulnerable module, potentially impacting the entire web application environment where DELUCKS SEO is deployed. This vulnerability is particularly relevant for websites using the DELUCKS SEO plugin, which is a tool designed to enhance search engine optimization in WordPress environments. Attackers could leverage this flaw to inject malicious scripts that compromise user sessions, deface websites, or redirect users to malicious sites, undermining trust and potentially causing reputational and operational damage.

For European organizations, especially those operating websites with WordPress installations using the DELUCKS SEO plugin, this vulnerability poses a tangible risk. Exploitation could lead to unauthorized access to user accounts, theft of sensitive data such as cookies or credentials, and manipulation of website content. This can result in reputational damage, loss of customer trust, and potential regulatory repercussions under GDPR if personal data is compromised. Additionally, attackers might use the vulnerability as a foothold for further attacks within the network or to distribute malware to site visitors. Given the medium severity and the requirement for some level of authenticated access, the threat is more pronounced for organizations with multiple users managing their SEO settings or content. The absence of a patch increases the window of exposure, and organizations may face challenges in mitigating risks without vendor support. The cross-site scripting nature also means that end-users, including customers and partners, could be targeted, amplifying the impact beyond the organization itself.

Organizations should immediately audit their WordPress installations to identify the presence of the DELUCKS SEO plugin and its version. Until an official patch is released, administrators should consider disabling or uninstalling the plugin to eliminate the attack surface. Implementing Web Application Firewalls (WAFs) with rules designed to detect and block XSS payloads can provide interim protection. Additionally, enforcing strict Content Security Policies (CSP) can help mitigate the impact of injected scripts by restricting the execution of unauthorized code. Organizations should also review user privileges to minimize the number of users with permissions to input or manage SEO content, reducing the risk of malicious input. Regular security training for administrators and content managers to recognize suspicious activities and input validation best practices is recommended. Monitoring website logs for unusual input patterns or error messages related to the plugin can aid in early detection of exploitation attempts. Finally, organizations should maintain up-to-date backups to enable rapid recovery in case of compromise.