CVE-2025-52871 – An out-of-bounds read vulnerability in QNAP Lic... (How to Fix)

Q: What is the severity of CVE-2025-52871?

CVE-2025-52871 has a CVSS score of 6.5 (MEDIUM). An out-of-bounds read vulnerability in QNAP License Center allows authenticated remote attackers to read sensitive memory contents. This affects users of QNAP License Center who have not updated to version 2.0.36 or later. Attackers need valid user credentials to exploit this vulnerability.

📋 TL;DR

An out-of-bounds read vulnerability in QNAP License Center allows authenticated remote attackers to read sensitive memory contents. This affects users of QNAP License Center who have not updated to version 2.0.36 or later. Attackers need valid user credentials to exploit this vulnerability.

💻 Affected Systems

Products:

QNAP License Center

Versions: Versions prior to 2.0.36

Operating Systems: QTS, QuTS hero

Default Config Vulnerable: ⚠️ Yes

Notes: Affects QNAP NAS devices running vulnerable versions of License Center. Requires attacker to have user account access.

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete compromise of sensitive data including credentials, encryption keys, or other secrets stored in memory, potentially leading to full system compromise.

🟠

Likely Case

Information disclosure of limited memory contents, potentially exposing some sensitive configuration data or partial secrets.

🟢

If Mitigated

No impact if proper access controls prevent unauthorized users from accessing the License Center interface.

🌐 Internet-Facing: MEDIUM - Requires authentication but could be exploited if exposed to internet with weak credentials.

🏢 Internal Only: MEDIUM - Internal attackers with valid credentials could exploit to gain sensitive information.

🎯 Exploit Status

Public PoC: ✅ No

Weaponized: UNKNOWN

Unauthenticated Exploit: ✅ No

Complexity: MEDIUM

Requires authenticated access. No public exploit code known at this time.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: License Center 2.0.36 and later

Vendor Advisory: https://www.qnap.com/en/security-advisory/qsa-25-52

Restart Required: Yes

Instructions:

1. Log into QNAP NAS admin interface. 2. Go to App Center. 3. Check for updates to License Center. 4. Update to version 2.0.36 or later. 5. Restart the NAS or License Center service.

🔧 Temporary Workarounds

Restrict License Center Access

all

Limit access to License Center to only trusted users and networks

Implement Strong Authentication

all

Enforce strong passwords and consider multi-factor authentication for all user accounts

🧯 If You Can't Patch

Isolate License Center to internal network only, blocking external access
Implement strict access controls and monitor for unusual authentication attempts

🔍 How to Verify

Check if Vulnerable:

Check License Center version in QNAP App Center or via SSH: cat /etc/config/uLinux.conf | grep license_center_version

Check Version:

cat /etc/config/uLinux.conf | grep license_center_version

Verify Fix Applied:

Verify License Center version is 2.0.36 or higher in App Center or via version check command

📡 Detection & Monitoring

Log Indicators:

Unusual memory access patterns in system logs
Multiple failed authentication attempts followed by successful login

Network Indicators:

Unusual traffic to License Center port from unexpected sources

SIEM Query:

source="qnap_logs" AND (process="license_center" AND (event="memory_access" OR event="out_of_bounds"))

📊 Metadata

CVE ID: CVE-2025-52871

CVSS v3 Score: 6.5 (MEDIUM)

CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

CWE: CWE-125

Published: January 2, 2026

Last Updated: February 5, 2026

🤖 AI-assisted analysis, reviewed for accuracy

🔗 References

https://www.qnap.com/en/security-advisory/qsa-25-52 Vendor Advisory

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