CVE-2025-23184 is a denial of service vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) affecting Apache CXF, an open-source services framework widely used for building and developing web services. The vulnerability exists in versions prior to 3.5.10, 3.6.5, and 4.0.6. It stems from CachedOutputStream instances that, in some edge cases, are not properly closed. These streams, when backed by temporary files, can cause the file system to fill up as temporary files accumulate without being released. This uncontrolled consumption of disk space can lead to denial of service by exhausting storage resources on both servers and clients utilizing Apache CXF. The vulnerability does not impact confidentiality or integrity but severely affects availability. The CVSS 3.1 base score is 5.9 (medium severity), reflecting network attack vector, high attack complexity, no privileges required, and no user interaction needed. No known exploits have been reported in the wild, but the potential for disruption exists especially in environments with high request volumes or limited disk space. The issue affects multiple major versions, indicating a need for widespread patching. Since Apache CXF is commonly used in enterprise middleware and government services, the impact could be significant if exploited.

For European organizations, the primary impact is denial of service due to disk space exhaustion on systems running vulnerable Apache CXF versions. This can disrupt critical web services, middleware communications, and service-oriented architectures that rely on Apache CXF for SOAP or RESTful services. Organizations with limited disk monitoring or those operating in high-load environments are at greater risk. The disruption could affect financial services, government portals, healthcare systems, and other sectors relying on stable middleware infrastructure. While the vulnerability does not compromise data confidentiality or integrity, the availability impact can lead to operational downtime, loss of productivity, and potential regulatory compliance issues related to service availability. The lack of known exploits reduces immediate risk but does not eliminate the threat, especially as attackers may develop exploits targeting this vulnerability.

1. Upgrade Apache CXF to versions 3.5.10, 3.6.5, or 4.0.6 or later where the issue is fixed. 2. Implement proactive monitoring of disk usage, especially in directories used for temporary files by Apache CXF, to detect abnormal growth early. 3. Configure system-level quotas or limits on temporary file storage to prevent full disk exhaustion. 4. Review and audit application logs and resource usage patterns to identify potential edge cases triggering unclosed CachedOutputStream instances. 5. In environments where immediate upgrade is not feasible, consider deploying network-level protections to limit exposure and rate-limit requests to reduce resource consumption. 6. Educate development and operations teams about the vulnerability and ensure secure coding and resource management practices in services using Apache CXF.