CVE-2025-29898
📋 TL;DR
An uncontrolled resource consumption vulnerability in Qsync Central allows authenticated remote attackers to cause denial-of-service conditions. This affects all QNAP Qsync Central deployments running vulnerable versions. Attackers need valid user credentials to exploit this vulnerability.
💻 Affected Systems
- QNAP Qsync Central
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption of Qsync Central, preventing file synchronization and access to synchronized data across the organization.
Likely Case
Degraded performance or temporary service outages affecting file synchronization capabilities.
If Mitigated
Minimal impact with proper authentication controls and resource monitoring in place.
🎯 Exploit Status
Exploitation requires valid user credentials. The vulnerability is in resource consumption mechanisms.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 4.5.0.7 (released 2025/04/23) and later
Vendor Advisory: https://www.qnap.com/en/security-advisory/qsa-25-22
Restart Required: Yes
Instructions:
1. Log into QNAP App Center. 2. Check for updates to Qsync Central. 3. Install version 4.5.0.7 or later. 4. Restart Qsync Central service.
🔧 Temporary Workarounds
Restrict User Access
allLimit Qsync Central access to only necessary users and implement strong authentication controls.
Implement Rate Limiting
allConfigure network-level rate limiting for Qsync Central traffic to prevent resource exhaustion attacks.
🧯 If You Can't Patch
- Isolate Qsync Central to internal network only and restrict external access
- Implement strict user access controls and monitor for unusual resource consumption patterns
🔍 How to Verify
Check if Vulnerable:
Check Qsync Central version in QNAP App Center. If version is below 4.5.0.7, the system is vulnerable.Check Version:
Check via QNAP App Center GUI or SSH to NAS and check package versionVerify Fix Applied:
Verify Qsync Central version shows 4.5.0.7 or higher in App Center after update.📡 Detection & Monitoring
Log Indicators:
- Unusual resource consumption spikes
- Multiple failed authentication attempts followed by resource exhaustion
- Qsync Central service restart logs
Network Indicators:
- Abnormal traffic patterns to Qsync Central port
- Multiple connections from single source to Qsync Central
SIEM Query:
source="Qsync Central" AND (resource_usage>90% OR service_restart=true)