CVE-2025-52667 is a stored cross-site scripting vulnerability identified in Revive Adserver versions 5.5.2 and earlier, including 6.0.1. The root cause is the absence of a JSON Content-Type header in a particular script, which leads to improper handling of user-supplied input. This flaw allows a logged-in manager user to inject malicious JavaScript code that is stored persistently within the application and executed when other users access the affected functionality. The vulnerability requires authenticated access with manager-level privileges and user interaction to trigger the malicious payload, which limits the attack vector primarily to insider threats or compromised accounts. The CVSS v3.0 score is 3.5 (low), reflecting the limited impact on confidentiality and no impact on integrity or availability. Although no known exploits have been reported in the wild, the stored XSS could enable session hijacking, credential theft, or unauthorized actions within the adserver environment. The vulnerability highlights a common security oversight in web applications where content-type headers are not properly enforced, leading to unsafe script execution. Remediation involves correcting the content-type handling in the affected scripts and applying patches once released by the vendor. Additional security controls such as input sanitization, output encoding, and Content Security Policy (CSP) can further mitigate the risk of exploitation.

For European organizations, the primary impact of CVE-2025-52667 lies in the potential compromise of confidentiality through session hijacking or theft of sensitive information within the Revive Adserver platform. Since the vulnerability requires authenticated manager access, the risk is elevated if privileged accounts are compromised or if insider threats exist. Successful exploitation could allow attackers to execute arbitrary scripts in the context of the adserver, potentially manipulating ad campaigns or stealing data. However, the vulnerability does not affect system integrity or availability, limiting the scope of damage. Organizations heavily reliant on Revive Adserver for digital advertising management may face reputational damage and operational disruptions if attackers leverage this flaw. The lack of known exploits in the wild reduces immediate risk but does not eliminate the need for proactive mitigation. Given the widespread use of web-based ad management platforms in Europe, especially in countries with large digital marketing sectors, the vulnerability could be leveraged in targeted attacks against advertising infrastructure.

1. Apply official patches or updates from Revive as soon as they become available to address the missing JSON Content-Type header issue. 2. Enforce strict input validation and output encoding on all user-supplied data within the adserver to prevent injection of malicious scripts. 3. Implement a robust Content Security Policy (CSP) to restrict the execution of unauthorized scripts and reduce the impact of any stored XSS payloads. 4. Limit the number of users with manager-level privileges and enforce strong authentication mechanisms, including multi-factor authentication (MFA), to reduce the risk of account compromise. 5. Conduct regular security audits and code reviews focusing on content-type handling and script injection vulnerabilities. 6. Monitor logs and user activity for unusual behavior indicative of exploitation attempts. 7. Educate administrators and users about the risks of stored XSS and safe usage practices within the adserver environment.