CVE-2025-54147
📋 TL;DR
A NULL pointer dereference vulnerability in Qsync Central allows authenticated remote attackers to cause denial-of-service conditions. This affects organizations using vulnerable versions of Qsync Central for file synchronization. Attackers need valid user credentials to exploit this vulnerability.
💻 Affected Systems
- Qsync Central
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete service disruption of Qsync Central, preventing file synchronization services and potentially affecting dependent business processes.
Likely Case
Temporary service interruption requiring manual restart of Qsync Central service, causing synchronization delays.
If Mitigated
Minimal impact with proper authentication controls and network segmentation limiting attack surface.
🎯 Exploit Status
Requires authenticated access but exploitation appears straightforward once credentials are obtained.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Qsync Central 5.0.0.4 (2026/01/20) and later
Vendor Advisory: https://www.qnap.com/en/security-advisory/qsa-26-02
Restart Required: Yes
Instructions:
1. Log into QNAP device admin interface. 2. Navigate to App Center. 3. Check for Qsync Central updates. 4. Install version 5.0.0.4 or later. 5. Restart Qsync Central service.
🔧 Temporary Workarounds
Network Access Restriction
allRestrict network access to Qsync Central to trusted IP addresses only
Use QNAP firewall rules to limit access to specific IP ranges
Authentication Hardening
allImplement strong password policies and multi-factor authentication
Configure strong password requirements in QNAP user management
🧯 If You Can't Patch
- Isolate Qsync Central to internal network segments only
- Implement strict access controls and monitor for suspicious authentication attempts
🔍 How to Verify
Check if Vulnerable:
Check Qsync Central version in QNAP App Center - versions before 5.0.0.4 are vulnerableCheck Version:
Check via QNAP web interface: App Center → Installed Apps → Qsync CentralVerify Fix Applied:
Confirm Qsync Central version is 5.0.0.4 or later in App Center📡 Detection & Monitoring
Log Indicators:
- Unexpected Qsync Central service crashes
- Multiple failed authentication attempts followed by service disruption
Network Indicators:
- Unusual authentication patterns to Qsync Central service
- Traffic spikes followed by service unavailability
SIEM Query:
source="qnap" AND (process="Qsync Central" AND event="crash") OR (auth_failure AND destination_port=443)