CVE-2025-54155 is classified under CWE-770, indicating an allocation of resources without limits or throttling vulnerability in QNAP Systems Inc.'s File Station 5 software. This vulnerability allows a remote attacker who has already obtained administrator-level access to the affected File Station 5 (versions 5.5.x before 5.5.6.5018) to exploit the system's resource allocation mechanisms. By doing so, the attacker can monopolize certain system resources, preventing other systems, applications, or processes from accessing or utilizing those resources effectively. This can lead to denial of service conditions impacting the availability of the NAS device or services running on it. The vulnerability does not require user interaction but does require high privileges, meaning the attacker must have administrator credentials or access beforehand. The CVSS v4.0 score of 3.6 reflects a low severity primarily due to the prerequisite of administrative access and the limited scope of impact (availability only). No known exploits are reported in the wild, and the vendor has addressed the issue in File Station 5 version 5.5.6.5018 and later. The vulnerability underscores the importance of resource management and throttling in multi-tenant or multi-process environments to prevent denial of service scenarios caused by resource exhaustion.

For European organizations, the primary impact of CVE-2025-54155 is on the availability of QNAP NAS devices running vulnerable versions of File Station 5. If exploited, critical file storage and sharing services could become unavailable, disrupting business operations, data access, and collaboration. This is particularly significant for sectors relying heavily on NAS devices for centralized storage, such as finance, healthcare, manufacturing, and public administration. Although the vulnerability requires administrative access, insider threats or compromised credentials could enable exploitation. The denial of service caused by resource exhaustion could also affect backup processes, data synchronization, and other dependent applications, potentially leading to operational delays and increased recovery costs. However, since confidentiality and integrity are not directly impacted, the risk is primarily operational disruption rather than data breach. The low CVSS score reflects this limited impact, but organizations should not underestimate the operational risks associated with availability loss in critical infrastructure.

1. Immediately upgrade all QNAP File Station 5 instances to version 5.5.6.5018 or later to apply the official patch addressing this vulnerability. 2. Enforce strict access controls and monitoring on administrator accounts to prevent unauthorized access, including multi-factor authentication and regular credential audits. 3. Implement network segmentation and limit administrative access to NAS devices to trusted networks and personnel only. 4. Monitor resource usage patterns on NAS devices to detect abnormal resource consumption that could indicate exploitation attempts. 5. Regularly review and update incident response plans to include scenarios involving denial of service via resource exhaustion on storage devices. 6. Employ logging and alerting mechanisms to track administrative actions and resource allocation anomalies. 7. Educate administrators on the risks of privilege misuse and the importance of timely patching. 8. Consider deploying additional redundancy or failover mechanisms for critical NAS services to minimize operational impact during potential attacks.