Qsync CentralApplication · Qnap

CVE-2025-54148

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 · high confidence

A NULL pointer dereference vulnerability exists in Qsync Central that allows an authenticated remote attacker (attacker must first obtain a valid user account) to trigger a denial-of-service condition by exploiting the NULL pointer dereference in the software.

MitigationUpgrade Qsync Central to version 5.0.0.4 or later. Until the upgrade is applied, restrict user account access to trusted personnel and monitor for anomalous activity that could indicate exploitation attempts.

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. Verify Qsync Central is installed
    Access the QNAP NAS admin interface, go to App Center or check running services to confirm Qsync Central is installed and running. Alternatively, check via SSH with 'ps aux | grep -i qsync' or review installed packages.
    Affected if Qsync Central is found running on the system
  2. Determine installed Qsync Central version
    In QNAP admin interface, locate Qsync Central in App Center and view the version details. Via CLI, check '/share/CACHEDEV1_DATA/.qpkg/QsyncCentral' or use 'qpkg --info Qsync Central' if available. Compare against the affected range.
    Affected if Installed version is 5.0.0.0 through 5.0.0.3 (inclusive)
  3. Confirm user accounts exist on the system
    Check Qsync Central user management or NAS user accounts via the admin interface under 'Users' or 'Domain' settings. Since exploitation requires a valid user account, verify if any user accounts are configured.
    Affected if At least one user account exists in the system
  4. Check for remote access exposure
    Review Qsync Central network settings and NAS firewall rules to determine if the service is accessible from external networks. Verify if the QNAP device has port forwarding enabled or VPN access configured.
    Affected if Qsync Central is exposed to untrusted networks or remote access is enabled
  5. Review logs for crash indicators
    Check Qsync Central logs in the admin interface under 'Log Center' or inspect system logs via CLI in '/var/log/' for qsync-related errors, crashes, or sudden service restarts occurring after the software was deployed.
    Affected if Recent crashes, NULL pointer errors, or unexpected service restarts are logged for Qsync Central

A system is affected if Qsync Central version 5.0.0.0 through 5.0.0.3 is running and the attacker can obtain valid user credentials to authenticate remotely.

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. Until the upgrade is applied, restrict user account access to trusted personnel and monitor for anomalous activity that could indicate exploitation attempts.

Recommended fix High confidence

Qsync Central 5.0.0.4

  1. Back up the current Qsync Central configuration before starting the upgrade process
  2. Obtain Qsync Central version 5.0.0.4 or later from the official QNAP download center
  3. Install the updated Qsync Central version following QNAP's standard upgrade procedures
  4. After upgrade, verify that the Qsync Central service is running normally
  5. Confirm the version number matches 5.0.0.4 or higher to ensure the vulnerability is patched

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

Fix this in Qsync Central Scoped from the published advisory
  • Consultation3.0 h
  • Implementation2.0 h
  • Testing3.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,770
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,832.

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-2025-54148 in production — separate from our analysis above.

No notes yet

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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