CVE-2025-55128 is an uncontrolled resource consumption vulnerability identified in Revive Adserver version 6, specifically within the userlog-index.php script. The flaw allows an attacker who has authenticated access to the administrative interface to manipulate the number of items requested per page to an arbitrarily large value. This leads to excessive consumption of server resources such as memory and CPU, potentially causing a denial of service (DoS) condition by overwhelming the server and degrading or crashing the ad server application. The vulnerability does not affect confidentiality or integrity, as it does not allow data leakage or modification. Exploitation requires valid admin credentials but no additional user interaction. The CVSS 3.0 base score is 6.5, reflecting medium severity primarily due to the impact on availability and the requirement for privileges. No public exploits have been reported yet, but the vulnerability poses a risk to organizations relying on Revive Adserver for ad delivery and analytics. Since Revive Adserver is an open-source ad serving platform widely used by digital publishers and advertisers, this vulnerability could disrupt ad operations and revenue streams if exploited.

For European organizations using Revive Adserver version 6, this vulnerability could lead to service outages or degraded performance of their ad serving infrastructure. This impacts availability, potentially causing loss of ad impressions, revenue, and user trust. Organizations relying on continuous ad delivery for monetization or marketing campaigns may experience operational disruptions. While confidentiality and integrity are not directly affected, the denial of service could indirectly impact business operations and customer experience. The requirement for admin-level access limits the attack surface, but insider threats or compromised admin accounts could be exploited. The lack of known exploits reduces immediate risk, but the vulnerability should be addressed promptly to prevent future attacks. Given the importance of digital advertising in European markets, especially in countries with large media and publishing sectors, the impact could be significant if exploited at scale.

1. Immediately apply any available patches or updates from Revive to address CVE-2025-55128. 2. If patches are not yet available, implement rate limiting or input validation on the admin interface to restrict the maximum number of items per page requested in userlog-index.php. 3. Restrict administrative access to trusted personnel and enforce strong authentication mechanisms, including multi-factor authentication (MFA). 4. Monitor server resource usage and logs for unusual spikes in requests to the userlog-index.php page or abnormal admin interface activity. 5. Consider isolating the ad server environment and applying network segmentation to limit exposure. 6. Regularly audit admin accounts and revoke unnecessary privileges to reduce the risk of insider exploitation. 7. Educate administrators about the risks of this vulnerability and encourage prompt reporting of suspicious activity. 8. Employ web application firewalls (WAFs) to detect and block abnormal request patterns targeting this vulnerability.