CVE-2025-53020 is a vulnerability classified under CWE-401, which refers to a 'Missing Release of Memory after Effective Lifetime.' This issue affects the Apache HTTP Server versions from 2.4.17 up to 2.4.63. The vulnerability arises due to the server failing to properly release allocated memory after it is no longer needed, leading to a late release or potential memory leak. Over time, this can cause the server process to consume increasing amounts of memory, potentially degrading performance or causing denial of service (DoS) conditions due to resource exhaustion. The vulnerability does not require authentication or user interaction to be triggered, as it is related to the internal memory management of the server during normal operation. Although no known exploits are currently reported in the wild, the widespread use of Apache HTTP Server and the nature of the vulnerability make it a concern for organizations relying on these affected versions. The Apache Software Foundation has addressed this issue in version 2.4.64, and users are strongly advised to upgrade to this version to mitigate the risk.

For European organizations, the impact of this vulnerability can be significant, especially for those running web services on affected Apache HTTP Server versions. Memory leaks can lead to gradual degradation of server performance, increased latency, and eventual service outages if the server exhausts available memory. This can disrupt business operations, degrade user experience, and potentially cause financial losses. Critical infrastructure and public sector services relying on Apache HTTP Server may face increased risk of denial of service, which could affect service availability to citizens and businesses. Additionally, organizations with strict uptime and availability requirements, such as financial institutions and e-commerce platforms, may experience reputational damage and compliance issues if service disruptions occur. Although this vulnerability does not directly lead to data breaches, the resulting denial of service can indirectly impact confidentiality and integrity by forcing emergency changes or exposing systems during recovery.

European organizations should prioritize upgrading all Apache HTTP Server instances from versions 2.4.17 through 2.4.63 to version 2.4.64 or later, where the memory management issue is resolved. Beyond upgrading, organizations should implement proactive monitoring of server memory usage and performance metrics to detect abnormal memory consumption early. Employing automated alerts for memory usage thresholds can enable rapid response before service degradation occurs. Additionally, organizations should conduct regular audits of their web server configurations and patch management processes to ensure timely application of security updates. For environments where immediate upgrading is not feasible, consider implementing resource limits at the operating system level (e.g., cgroups on Linux) to contain the impact of memory leaks. Finally, organizations should review their incident response plans to include scenarios involving memory exhaustion and denial of service, ensuring preparedness for potential service disruptions.