CVE-2025-54151 Overview
An uncontrolled resource consumption vulnerability has been identified in QNAP Qsync Central, a file synchronization application for QNAP NAS devices. This vulnerability allows a local attacker who has gained access to a user account to exploit the flaw and launch a denial-of-service (DoS) attack against the affected system. The vulnerability stems from improper resource limitation mechanisms within the Qsync Central application.
Critical Impact
Authenticated attackers can exhaust system resources, causing service disruption and denial of service conditions on QNAP NAS devices running vulnerable versions of Qsync Central.
Affected Products
- QNAP Qsync Central versions prior to 5.0.0.4
- QNAP NAS devices running vulnerable Qsync Central installations
Discovery Timeline
- 2026-01-20 - QNAP releases security patch in Qsync Central version 5.0.0.4
- 2026-02-11 - CVE-2025-54151 published to NVD
- 2026-02-12 - Last updated in NVD database
Technical Details for CVE-2025-54151
Vulnerability Analysis
This vulnerability is classified under CWE-400 (Uncontrolled Resource Consumption) and CWE-770 (Allocation of Resources Without Limits or Throttling). The flaw exists in how Qsync Central handles resource allocation when processing requests from authenticated users. Without proper controls on resource consumption, an attacker with valid credentials can trigger excessive resource usage, leading to service degradation or complete denial of service.
The attack requires network access and low-privilege authentication, meaning the attacker must first obtain valid user credentials to exploit this vulnerability. Once authenticated, the attacker can submit specially crafted requests that consume disproportionate amounts of system resources such as memory, CPU cycles, or storage I/O on the NAS device.
Root Cause
The root cause of this vulnerability lies in the absence of proper resource limitation and throttling mechanisms within Qsync Central. The application fails to adequately restrict the amount of resources that can be consumed by individual user sessions or requests, allowing authenticated users to exhaust available system resources.
Attack Vector
The attack vector is network-based, requiring the attacker to first obtain valid user credentials for the Qsync Central application. Once authenticated, the attacker can initiate resource-intensive operations without proper rate limiting or resource caps. This could involve triggering excessive file synchronization operations, memory-intensive processing tasks, or other resource-consuming activities that the application fails to properly constrain.
The vulnerability can be exploited remotely over the network, though it requires low-privilege authentication. No user interaction is required beyond the initial authentication, making automated exploitation feasible once credentials are obtained.
Detection Methods for CVE-2025-54151
Indicators of Compromise
- Unusual spikes in CPU or memory utilization on QNAP NAS devices running Qsync Central
- Abnormal volume of requests from specific authenticated user accounts
- System logs indicating resource exhaustion or out-of-memory conditions
- Degraded performance or unresponsiveness of Qsync Central services
Detection Strategies
- Monitor system resource utilization for anomalous patterns, particularly during Qsync Central operations
- Implement alerting for sustained high resource consumption by the Qsync Central process
- Review authentication logs for suspicious login patterns or unusual account activity
- Deploy network monitoring to identify abnormal traffic volumes to Qsync Central endpoints
Monitoring Recommendations
- Configure resource monitoring thresholds for CPU, memory, and I/O on QNAP NAS devices
- Enable detailed logging for Qsync Central authentication and synchronization activities
- Implement baseline monitoring to detect deviations from normal resource consumption patterns
- Set up automated alerts for service availability degradation
How to Mitigate CVE-2025-54151
Immediate Actions Required
- Update Qsync Central to version 5.0.0.4 or later immediately
- Review user accounts with access to Qsync Central and remove unnecessary privileges
- Implement network segmentation to limit exposure of NAS devices
- Monitor for signs of exploitation while applying patches
Patch Information
QNAP has released a security patch addressing this vulnerability in Qsync Central version 5.0.0.4, released on 2026-01-20. Organizations should prioritize updating to this version or later to remediate the vulnerability. For detailed patching instructions, refer to the QNAP Security Advisory QSA-26-02.
Workarounds
- Restrict network access to Qsync Central to trusted IP addresses only
- Implement strong authentication requirements and review user account permissions
- Consider temporarily disabling Qsync Central if not critical to operations until the patch can be applied
- Deploy rate limiting at the network level to constrain potential resource exhaustion attacks
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
