CVE-2025-52669 identifies a vulnerability in the user management system of Revive Adserver versions 5.5.2, 6.0.1, and earlier. The core issue stems from insecure design policies that allow non-administrative users to access sensitive personal information—specifically, the contact names and email addresses of other users within the system. This exposure occurs because the access control mechanisms governing user data visibility are insufficiently restrictive, permitting privilege escalation in terms of data access without granting full administrative rights. The vulnerability is network exploitable with low complexity, requiring only that an attacker have authenticated user privileges (non-admin) but no additional user interaction. The impact is limited to confidentiality, as the vulnerability does not allow modification or deletion of data (integrity) nor does it disrupt service availability. No known public exploits or active exploitation campaigns have been reported to date. The vulnerability was published on November 20, 2025, with a CVSS v3.0 base score of 4.3, categorized as medium severity. The affected product, Revive Adserver, is an open-source ad serving platform widely used for managing and delivering online advertisements. The flaw could enable attackers to harvest user contact information, potentially facilitating targeted phishing attacks or social engineering campaigns. The lack of patches at the time of disclosure necessitates immediate administrative action to limit exposure.

For European organizations, this vulnerability primarily threatens the confidentiality of user data within Revive Adserver installations. Exposure of contact names and email addresses can lead to increased phishing, spear-phishing, and social engineering risks, potentially compromising broader organizational security. While the vulnerability does not directly impact system integrity or availability, the leakage of personal information can erode trust, violate data protection regulations such as GDPR, and result in reputational damage and regulatory penalties. Organizations relying on Revive Adserver for digital advertising campaigns may face operational disruptions if attackers leverage the exposed information to conduct further attacks. The medium severity rating reflects the limited scope of impact but acknowledges the ease with which an authenticated non-admin user can exploit the flaw. Given the importance of data privacy in Europe, even limited data exposure can have significant compliance and legal consequences.

To mitigate CVE-2025-52669, European organizations should immediately audit and restrict user permissions within Revive Adserver, ensuring that non-admin users have no access to other users' contact information. Implement strict role-based access controls (RBAC) and review user roles to minimize privilege creep. Monitor access logs for unusual queries or data access patterns indicative of exploitation attempts. Since no official patches are available at disclosure, consider temporarily disabling user management features or restricting access to trusted administrators only. Engage with the Revive Adserver vendor or community to obtain or contribute to patches addressing this vulnerability. Additionally, educate users about phishing risks and implement email filtering solutions to reduce the impact of potential phishing campaigns leveraging exposed contact data. Regularly update and harden the server environment hosting Revive Adserver to reduce attack surface and prevent lateral movement.