CVE-2025-39412 is a Missing Authorization vulnerability (CWE-862) identified in the Averta Master Slider plugin, affecting versions up to 3.10.8. This vulnerability arises when the software fails to properly enforce authorization checks on certain functions or endpoints, allowing an authenticated user with limited privileges (PR:L) to perform actions beyond their intended access rights. The CVSS 3.1 base score is 4.3 (medium severity), with an attack vector of network (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), no user interaction (UI:N), unchanged scope (S:U), no confidentiality impact (C:N), integrity impact (I:L), and no availability impact (A:N). This means that an attacker who has some level of authenticated access to the system can exploit this flaw remotely without user interaction to modify or manipulate data or settings that should be restricted, potentially leading to unauthorized changes within the affected system. The vulnerability does not affect confidentiality or availability but impacts the integrity of the system. No known exploits are currently reported in the wild, and no patches have been linked yet. The vulnerability was reserved in April 2025 and published in May 2025, indicating it is a recent discovery. The affected product, Master Slider, is a widely used plugin for creating responsive sliders in web content management systems, commonly WordPress. Missing authorization vulnerabilities can be leveraged to escalate privileges or perform unauthorized actions, which may lead to further compromise if chained with other vulnerabilities or misconfigurations.

For European organizations, the impact of CVE-2025-39412 depends largely on the extent to which they use the Averta Master Slider plugin in their web infrastructure. Since this plugin is often integrated into websites for content display, unauthorized integrity modifications could lead to defacement, insertion of malicious content, or unauthorized changes to website behavior. This can damage brand reputation, reduce customer trust, and potentially expose organizations to regulatory scrutiny under GDPR if personal data is indirectly affected or if the integrity breach leads to data manipulation. While the vulnerability does not directly compromise confidentiality or availability, the integrity impact can facilitate further attacks or misinformation. Organizations in sectors such as e-commerce, media, and public services, which rely heavily on web presence, may face operational disruptions or reputational harm. Additionally, since the vulnerability requires authenticated access, insider threats or compromised user accounts could be leveraged to exploit this flaw, emphasizing the need for strict access controls and monitoring.

Organizations should immediately audit their use of the Averta Master Slider plugin and verify the version in use. Although no official patches are linked yet, monitoring vendor advisories for updates or patches is critical. In the interim, restrict access to the plugin’s administrative or configuration interfaces to trusted users only, employing the principle of least privilege. Implement robust authentication mechanisms, including multi-factor authentication (MFA), to reduce the risk of credential compromise. Conduct regular reviews of user permissions to ensure no excessive privileges are granted. Employ web application firewalls (WAFs) with custom rules to detect and block suspicious requests targeting the plugin’s endpoints. Additionally, monitor logs for unusual activity related to the plugin. If feasible, consider temporarily disabling or replacing the plugin with alternative solutions until a patch is available. Finally, educate administrators and developers about the risks of missing authorization vulnerabilities and encourage secure coding and configuration practices.