CVE-2025-63045 identifies a DOM-based Cross-site Scripting (XSS) vulnerability in the averta Master Slider Pro plugin, affecting versions up to and including 3.7.12. The vulnerability stems from improper neutralization of user-supplied input during the generation of web pages, which allows malicious actors to inject and execute arbitrary JavaScript code within the context of the affected web application. This type of XSS is client-side and occurs when the application uses unsafe methods to handle input that is reflected in the DOM without proper sanitization or encoding. The vulnerability requires an attacker to have low privileges (PR:L) and some user interaction (UI:R), such as tricking a user into clicking a crafted link or visiting a malicious page that triggers the payload. The CVSS vector indicates network attack vector (AV:N), low attack complexity (AC:L), and a scope change (S:C), meaning the vulnerability can affect resources beyond the vulnerable component. The impact includes partial loss of confidentiality, integrity, and availability, as attackers can steal session tokens, manipulate page content, or perform actions on behalf of the user. No public exploits are currently known, but the vulnerability is publicly disclosed and should be considered a medium risk. The plugin is commonly used in WordPress environments to create sliders and interactive content, making it a target for attackers seeking to compromise websites that rely on this component. The lack of an official patch link suggests that remediation may require monitoring vendor updates or applying manual mitigations.

For European organizations, this vulnerability can lead to significant risks including session hijacking, unauthorized actions performed in the context of authenticated users, theft of sensitive information, and website defacement. Organizations relying on Master Slider Pro for customer-facing websites or internal portals may experience reputational damage and potential regulatory consequences under GDPR if personal data is compromised. The medium severity rating reflects the need for user interaction and low privileges, which somewhat limits exploitation but does not eliminate risk, especially in environments with high user traffic or where social engineering can be effective. The scope change in the CVSS vector indicates that the vulnerability could impact other components or data beyond the plugin itself, increasing the potential damage. European businesses in sectors such as e-commerce, media, and government that use WordPress and related plugins are particularly vulnerable. The absence of known exploits in the wild provides a window for proactive defense, but attackers may develop exploits rapidly once the vulnerability is public.

Organizations should prioritize monitoring for official patches or updates from averta for Master Slider Pro and apply them promptly once available. In the interim, implement strict input validation and output encoding on all user-supplied data that interacts with the plugin to prevent malicious script injection. Employ Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS payloads. Review and harden web application firewall (WAF) rules to detect and block suspicious requests targeting the plugin. Conduct security awareness training to reduce the risk of successful social engineering attacks that could trigger exploitation. Additionally, consider isolating or disabling the plugin if it is not essential, or replacing it with a more secure alternative. Regularly audit web applications for XSS vulnerabilities using automated scanners and manual testing to identify and remediate similar issues proactively.