Qsync CentralApplication · Qnap

CVE-2025-54147

MEDIUM · 6.5 CVSS v3.1 Published 2026-02-11
Fix available
A fix is available. Upgrade to 5.0.0.4 or later.
See remediation →
71/100
Remediation priority · Elevated
Remotely reachable Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
A NULL pointer dereference vulnerability has been reported to affect Qsync Central. If a remote attacker gains a user account, they can then exploit the vulnerability to launch a denial-of-service (DoS) attack. We have already fixed the vulnerability in the following version: Qsync Central 5.0.0.4 ( 2026/01/20 ) and later

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · moderate confidence

A NULL pointer dereference vulnerability exists in Qsync Central that allows an authenticated remote attacker to cause a denial-of-service condition. The vulnerability is triggered when the attacker, after gaining a valid user account, exploits the NULL pointer dereference in the application's handling of certain operations.

MitigationUpgrade Qsync Central to version 5.0.0.4 or later. Prior to upgrading, ensure valid backups of configuration and data exist, and schedule the upgrade during a maintenance window to minimize business impact.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Qsync CentralApplication
Affected:>= 5.0.0.0, < 5.0.0.4

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

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

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check Qsync Central installed version
    Access the QNAP admin interface, navigate to the Qsync Central app, and view the version information, or use the QNAP command line to query the installed package version
    Affected if The installed version is 5.0.0.0, 5.0.0.1, 5.0.0.2, or 5.0.0.3 (any version >= 5.0.0.0 and less than 5.0.0.4)
  2. Confirm Qsync Central service is running
    Verify the Qsync Central service is active on the QNAP NAS device
    Affected if The service is running and accessible on the network
  3. Verify user authentication is configured
    Check that user accounts are created and authentication is enabled for Qsync Central access
    Affected if Valid user accounts exist in the system, as the attacker requires a valid user account to exploit the vulnerability

The environment is affected if Qsync Central version is 5.0.0.0 through 5.0.0.3 and the service is running with user authentication enabled.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 5.0.0.4 or later
Fixed in 5.0.0.4
Interim mitigation

Upgrade Qsync Central to version 5.0.0.4 or later. Prior to upgrading, ensure valid backups of configuration and data exist, and schedule the upgrade during a maintenance window to minimize business impact.

Recommended fix High confidence

Qsync Central 5.0.0.4 or later

  1. 1. Identify the current version of Qsync Central installed on your QNAP NAS by accessing the Qsync Central web interface or checking via QNAP's interface.
  2. 2. Navigate to the QNAP download center at www.qnap.com and locate Qsync Central version 5.0.0.4 or later.
  3. 3. Download the appropriate firmware/update package for your QNAP NAS model.
  4. 4. Install the update by accessing the Qsync Central admin interface and applying the update, or use QNAP's firmware update mechanism.
  5. 5. After installation, verify that Qsync Central has been updated to version 5.0.0.4 or later.
  6. 6. Confirm the vulnerability is remediated by verifying the service is running normally without unexpected restarts or errors.

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Qsync Central Scoped from the published advisory
  • Consultation1.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,040
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2025-54147 in production — separate from our analysis above.

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data