CVE-2025-63045 is a DOM-based Cross-site Scripting (XSS) vulnerability identified in the averta Master Slider Pro plugin, affecting versions up to 3.7.12. The vulnerability stems from improper neutralization of user-supplied input during the generation of web pages, which allows malicious scripts to be injected and executed in the context of the victim's browser. Unlike reflected or stored XSS, DOM-based XSS occurs entirely on the client side, where the manipulation of the Document Object Model leads to script execution without server-side sanitization. Attackers can exploit this by crafting malicious URLs or inputs that, when processed by the vulnerable plugin, execute arbitrary JavaScript code. This can result in session hijacking, theft of sensitive information such as cookies or credentials, defacement, or unauthorized actions performed on behalf of the user. The vulnerability does not require authentication, making it accessible to unauthenticated attackers, and does not currently have known exploits in the wild. The plugin is commonly used in WordPress environments to create responsive sliders, often on public-facing websites, increasing the exposure risk. The absence of a CVSS score indicates the need for an expert severity assessment. Given the nature of DOM-based XSS and the widespread use of the affected plugin, the vulnerability represents a significant security risk that must be addressed promptly.

For European organizations, the impact of CVE-2025-63045 can be substantial, particularly for those relying on the Master Slider Pro plugin in their WordPress-based websites. Successful exploitation could lead to compromise of user sessions, enabling attackers to impersonate legitimate users, steal sensitive data, or perform unauthorized actions within the victim's browser context. This can damage organizational reputation, lead to data breaches involving personal or financial information, and potentially violate GDPR requirements concerning data protection and breach notification. Public-facing websites, especially those handling user logins or sensitive transactions, are at higher risk. Additionally, attackers could leverage this vulnerability as a foothold for further attacks, such as delivering malware or phishing content to site visitors. The lack of known exploits currently provides a window for proactive mitigation, but the ease of exploitation and broad potential impact make it critical for European entities to act swiftly.

1. Monitor for and apply security patches from averta as soon as they are released to address this vulnerability. 2. In the absence of an immediate patch, implement strict input validation and output encoding on all user-supplied data processed by the plugin, focusing on sanitizing inputs that influence DOM manipulation. 3. Deploy Content Security Policy (CSP) headers to restrict the execution of unauthorized scripts and reduce the impact of potential XSS attacks. 4. Conduct a thorough audit of all web applications using Master Slider Pro to identify and isolate vulnerable instances. 5. Educate web developers and administrators on secure coding practices related to DOM manipulation and XSS prevention. 6. Utilize Web Application Firewalls (WAFs) with rules tailored to detect and block XSS attack patterns targeting this plugin. 7. Regularly scan websites for XSS vulnerabilities using automated tools and manual testing to detect any residual or emerging issues. 8. Implement multi-factor authentication (MFA) for user accounts to mitigate the impact of session hijacking if exploitation occurs.