CVE-2025-30260 Overview
CVE-2025-30260 affects QNAP Qsync Central, a centralized file synchronization service for QNAP NAS devices. The vulnerability stems from allocation of resources without limits or throttling [CWE-770]. An authenticated remote attacker with a valid user account can exhaust shared resources on the host. The condition prevents other systems, applications, or processes from accessing the affected resource type, degrading availability for legitimate users. QNAP addressed the issue in Qsync Central 4.5.0.7, released on April 23, 2025.
Critical Impact
An authenticated remote attacker can trigger resource exhaustion in Qsync Central, denying service to co-located applications and users on the affected QNAP device.
Affected Products
- QNAP Qsync Central versions prior to 4.5.0.7
- QNAP NAS devices running vulnerable Qsync Central builds
- Environments where Qsync Central shares resources with other QNAP services
Discovery Timeline
- 2025-08-29 - CVE-2025-30260 published to the National Vulnerability Database
- 2025-04-23 - QNAP releases Qsync Central 4.5.0.7 containing the fix
- 2026-10-18 - Last updated in NVD database
Technical Details for CVE-2025-30260
Vulnerability Analysis
The flaw is categorized as resource allocation without limits or throttling [CWE-770]. Qsync Central accepts requests from authenticated users without enforcing upper bounds on the resources those requests consume. An attacker who obtains any valid user account can issue operations that monopolize memory, file handles, connections, or processing capacity. Because the shared resource is exhausted at the service or system layer, the impact extends beyond Qsync Central itself. Other applications and processes depending on the same resource pool lose access, producing a denial-of-service condition on the NAS appliance.
Root Cause
Qsync Central does not apply quotas, rate limits, or per-user throttling on the affected request handling path. Legitimate workflows and abusive request patterns share the same unbounded allocation logic, allowing a single authenticated session to consume disproportionate capacity.
Attack Vector
Exploitation requires network reachability to the Qsync Central service and low-privilege authenticated access. The attacker does not need user interaction or elevated permissions. Once authenticated, repeated or oversized requests exhaust the resource type referenced in QNAP advisory QSA-25-22, degrading availability.
No verified proof-of-concept code is publicly available. For technical specifics, refer to the QNAP Security Advisory QSA-25-22.
Detection Methods for CVE-2025-30260
Indicators of Compromise
- Sudden spikes in Qsync Central CPU, memory, or connection usage attributable to a single authenticated user
- Service degradation or crashes in co-resident QNAP applications on the same NAS
- Unusually high volumes of sync API calls from one account within a short time window
Detection Strategies
- Monitor Qsync Central logs for abnormal request rates per user account
- Correlate NAS system resource telemetry with Qsync Central session activity to identify exhaustion patterns
- Alert on repeated authentication from the same account followed by sustained high-volume sync operations
Monitoring Recommendations
- Baseline normal Qsync Central resource consumption and alert on sustained deviations
- Forward QNAP system and application logs to a centralized log platform for retention and correlation
- Track account creation and privilege changes on NAS devices to detect precursor activity
How to Mitigate CVE-2025-30260
Immediate Actions Required
- Upgrade Qsync Central to version 4.5.0.7 or later on all affected QNAP NAS devices
- Audit Qsync Central user accounts and remove unused or weakly protected credentials
- Enforce strong, unique passwords and enable two-factor authentication for all QNAP accounts
Patch Information
QNAP released Qsync Central 4.5.0.7 on April 23, 2025 to resolve the vulnerability. Administrators should install the update through the QNAP App Center. Full details are available in QNAP Security Advisory QSA-25-22.
Workarounds
- Restrict network access to Qsync Central using firewall rules or VPN-only reachability until patching completes
- Limit the number of accounts authorized to use Qsync Central and disable the service on devices that do not require it
- Apply QNAP IP access protection to throttle repeated connections from the same source
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
