Qsync CentralApplication · Qnap

CVE-2025-44008

MEDIUM · 6.5 CVSS v3.1 Published 2025-10-03
Fix available
A fix is available. Upgrade to 5.0.0.1 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 5.0.0.1 ( 2025/07/09 ) 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

This is a NULL pointer dereference vulnerability in Qsync Central that allows an authenticated remote attacker with a valid user account to crash the application, causing a denial-of-service condition. The vulnerability stems from improper validation or handling that leads to dereferencing a null pointer during certain operations.

MitigationUpgrade Qsync Central to version 5.0.0.1 or later. Additionally, limit user account creation and enforce strong authentication to reduce the attack surface, as a valid user account is required to exploit this vulnerability.

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:>= 4.2.0.0, < 5.0.0.1

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
    Check if Qsync Central is present on the QNAP system. This can be done via the QNAP App Center or by checking for the Qsync Central process/service running on the system.
    Affected if Qsync Central is not installed or not running
  2. Determine installed version
    Locate the version of Qsync Central installed. This is typically viewable in the QNAP App Center, or via the Qsync Central web interface under System Settings > About, or by querying the Qsync service directly.
    Affected if Version cannot be determined or is not visible
  3. Compare version to affected range
    Check if the installed version falls within >= 4.2.0.0 and < 5.0.0.1. Any version from 4.2.0.0 up to but not including 5.0.0.1 is affected.
    Affected if Installed version is 4.2.0.0 or higher but lower than 5.0.0.1
  4. Confirm user account configuration
    Verify whether user accounts are enabled in Qsync Central. Check System Settings > User Management in the Qsync Central interface, or review if LDAP/local user authentication is active for Qsync services.
    Affected if User accounts are configured and enabled in Qsync Central

The environment is affected if Qsync Central is installed with a version between 4.2.0.0 and 5.0.0.1 (exclusive) and user accounts are enabled, since a valid user account is required to exploit this vulnerability.

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 5.0.0.1 or later
Fixed in 5.0.0.1
Interim mitigation

Upgrade Qsync Central to version 5.0.0.1 or later. Additionally, limit user account creation and enforce strong authentication to reduce the attack surface, as a valid user account is required to exploit this vulnerability.

Recommended fix High confidence

Qsync Central 5.0.0.1

  1. 1. Back up the current Qsync Central configuration and any important data
  2. 2. Log in to the QNAP NAS admin interface
  3. 3. Navigate to the App Center or Qsync Central management page
  4. 4. Check the current installed version to confirm it is below 5.0.0.1
  5. 5. Update Qsync Central to version 5.0.0.1 or later via the QNAP App Center, or manually download and install the update from QNAP's official download center
  6. 6. After installation completes, verify that Qsync Central is now running version 5.0.0.1 or later
  7. 7. Test that Qsync Central functionality is working normally
Caveat Minor compatibility changes may occur; review QNAP release notes for any configuration or feature changes

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

Fix this in Qsync Central Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing2.0 h
  • Review / QA1.0 h
7.0 hours of engineering $1,240
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $1,984.

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-2025-44008 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