CVE-2025-54149 is a vulnerability classified under CWE-400 (Uncontrolled Resource Consumption) affecting QNAP Systems Inc.'s Qsync Central software, specifically versions 5.0.x.x. The flaw allows a local attacker who has already obtained a user account on the system to exploit the vulnerability to cause a denial-of-service (DoS) condition by exhausting system resources. This could manifest as CPU, memory, or other resource depletion, leading to service degradation or complete unavailability of Qsync Central services. The vulnerability does not require network-level authentication but does require local user privileges, meaning an attacker must have a valid user account on the device. No user interaction is necessary to trigger the exploit. The CVSS 4.9 score reflects a medium severity, indicating moderate impact on availability with relatively low attack complexity. The vulnerability was addressed in Qsync Central version 5.0.0.4 released on January 20, 2026. No known exploits are currently reported in the wild. The vulnerability is significant because Qsync Central is widely used in QNAP NAS devices for file synchronization and collaboration, making availability critical for business continuity. The flaw could be leveraged by malicious insiders or attackers who have compromised user credentials to disrupt organizational operations.

For European organizations, the primary impact of CVE-2025-54149 is the potential disruption of file synchronization and storage services provided by Qsync Central on QNAP NAS devices. This could lead to downtime, loss of productivity, and interruption of business processes that depend on continuous access to synchronized files. Organizations in sectors such as finance, healthcare, manufacturing, and government that rely heavily on QNAP NAS for data sharing and backup may experience operational setbacks. Additionally, the DoS condition could be exploited as a diversion tactic while other attacks are carried out. Since the vulnerability requires local user access, insider threats or compromised user accounts pose the greatest risk. The medium severity rating suggests that while the impact is not catastrophic, it is sufficient to warrant prompt remediation to maintain service availability and prevent potential cascading effects on dependent systems.

1. Upgrade Qsync Central to version 5.0.0.4 or later immediately to apply the official patch addressing CVE-2025-54149. 2. Enforce strict user account management policies, including strong authentication mechanisms and regular review of user privileges to minimize the risk of unauthorized local access. 3. Implement network segmentation and access controls to limit local user access to Qsync Central systems only to trusted personnel. 4. Monitor system resource usage and logs for unusual spikes or patterns that may indicate exploitation attempts. 5. Employ endpoint detection and response (EDR) solutions to detect anomalous behavior from user accounts on NAS devices. 6. Educate users about the risks of credential compromise and enforce multi-factor authentication (MFA) where possible. 7. Regularly back up critical data stored on QNAP devices to mitigate the impact of potential service disruptions. 8. Consider deploying intrusion prevention systems (IPS) that can detect and block attempts to exploit resource exhaustion vulnerabilities locally.