CVE-2025-47208
📋 TL;DR
This CVE describes a resource exhaustion vulnerability in QNAP operating systems where authenticated remote attackers can allocate resources without limits, potentially causing denial-of-service conditions. It affects multiple QNAP OS versions, requiring attackers to first obtain valid user credentials. The vulnerability prevents legitimate systems and processes from accessing the same resources.
💻 Affected Systems
- QNAP QTS
- QNAP QuTS hero
⚠️ Risk & Real-World Impact
Worst Case
Complete denial-of-service affecting critical QNAP services, potentially rendering the device unusable until manual intervention or reboot.
Likely Case
Degraded performance or temporary unavailability of specific services on the QNAP device, affecting users and applications dependent on those resources.
If Mitigated
Minimal impact with proper access controls and monitoring in place to detect abnormal resource consumption patterns.
🎯 Exploit Status
Exploitation requires valid user credentials first. No public exploit code has been reported as of the advisory date.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: QTS 5.2.6.3195 build 20250715 and later, QuTS hero h5.2.6.3195 build 20250715 and later
Vendor Advisory: https://www.qnap.com/en/security-advisory/qsa-25-50
Restart Required: Yes
Instructions:
1. Log into QNAP web interface as administrator. 2. Navigate to Control Panel > System > Firmware Update. 3. Check for updates and install the latest version. 4. Reboot the device after installation completes.
🔧 Temporary Workarounds
Restrict network access
allLimit QNAP device access to trusted networks only, reducing attack surface.
Implement strong authentication controls
allEnforce strong passwords, multi-factor authentication, and limit user privileges to reduce credential compromise risk.
🧯 If You Can't Patch
- Implement network segmentation to isolate QNAP devices from critical systems
- Deploy monitoring for abnormal resource consumption patterns and set up alerts
🔍 How to Verify
Check if Vulnerable:
Check QNAP OS version via web interface: Control Panel > System > Firmware Update, or via SSH: cat /etc/config/uLinux.conf | grep versionCheck Version:
cat /etc/config/uLinux.conf | grep versionVerify Fix Applied:
Verify OS version is QTS 5.2.6.3195 build 20250715 or later, or QuTS hero h5.2.6.3195 build 20250715 or later📡 Detection & Monitoring
Log Indicators:
- Unusual resource consumption patterns
- Multiple failed authentication attempts followed by successful login
- Abnormal process creation or resource allocation
Network Indicators:
- Excessive network traffic to QNAP device from single source
- Authentication requests from unexpected IP addresses
SIEM Query:
source="qnap_logs" AND (event_type="resource_exhaustion" OR event_type="authentication_success" FROM new_ip)