CVE-2025-54150 is classified under CWE-400, indicating an uncontrolled resource consumption vulnerability in QNAP Systems Inc.'s Qsync Central software, specifically affecting version 5.0.x.x. The vulnerability allows a local attacker, who has already obtained a user account, to exploit the system by consuming excessive resources, leading to denial-of-service (DoS) conditions. This could manifest as system slowdowns, crashes, or unavailability of synchronization services provided by Qsync Central. The attack vector requires network access (AV:N) and low attack complexity (AC:L), with no privileges beyond a user account (PR:L) and no user interaction (UI:N). The vulnerability does not impact confidentiality, integrity, or availability beyond the resource exhaustion effect (VA:H). The vendor addressed the issue in version 5.0.0.4 released on January 20, 2026. No public exploits have been reported, but the medium CVSS score (4.9) reflects the moderate impact and ease of exploitation by authenticated users. Qsync Central is widely used for file synchronization and sharing in enterprise environments, making availability critical. The vulnerability stems from insufficient controls on resource allocation or cleanup, allowing attackers to trigger excessive consumption, potentially by repeated or malformed requests or operations within the software.

For European organizations, the primary impact of CVE-2025-54150 is the potential disruption of file synchronization services, which can affect business continuity and productivity. Organizations relying on Qsync Central for critical data sharing and backup may experience service outages or degraded performance, impacting operational workflows. This could be particularly damaging for sectors such as finance, healthcare, and government, where data availability is essential. Although the vulnerability does not directly compromise data confidentiality or integrity, the denial-of-service effect can indirectly affect incident response and recovery processes. Additionally, organizations with large user bases or extensive deployment of Qsync Central are at higher risk of widespread impact. The requirement for a valid user account means insider threats or compromised credentials could be leveraged to exploit this vulnerability. Given the medium severity, the threat is significant but not catastrophic, emphasizing the need for timely patching and monitoring.

European organizations should prioritize upgrading Qsync Central to version 5.0.0.4 or later to remediate the vulnerability. In addition to patching, organizations should implement strict user account management, including enforcing strong authentication mechanisms and monitoring for unusual login patterns to reduce the risk of account compromise. Network segmentation and access controls can limit exposure of Qsync Central instances to only trusted users and networks. Resource usage monitoring and alerting should be established to detect abnormal consumption patterns indicative of exploitation attempts. Implementing rate limiting or throttling on Qsync Central operations may help mitigate resource exhaustion risks. Regular security audits and vulnerability assessments of QNAP deployments are recommended to ensure no residual or related issues persist. Finally, organizations should maintain incident response plans that include procedures for DoS scenarios affecting synchronization services.