dbcve.org
QtsOperating system · Qnap

CVE-2023-39303

CRITICAL · 9.8 CVSS v3.1 Published 2024-02-02
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges 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
An improper authentication vulnerability has been reported to affect several QNAP operating system versions. If exploited, the vulnerability could allow users to compromise the security of the system via a network. We have already fixed the vulnerability in the following versions: QTS 5.1.3.2578 build 20231110 and later QuTS hero h5.1.3.2578 build 20231110 and later QuTScloud c5.1.5.2651 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 an improper authentication vulnerability in QNAP QTS, QuTS hero, and QuTScloud operating systems. The vulnerability allows remote network attackers to bypass authentication mechanisms to compromise system security. CVSS 9.8 indicates the exploit requires no privileges or user interaction and is easily exploitable over the network.

MitigationOrganizations should update affected QNAP devices to the fixed versions: QTS 5.1.3.2578 build 20231110, QuTS hero h5.1.3.2578 build 20231110, or QuTScloud c5.1.5.2651 and later.

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
QtsOperating system
Affected:= 5.1.0.2348= 5.1.0.2399= 5.1.0.2418= 5.1.0.2444= 5.1.0.2466= 5.1.1.2491= 5.1.2.2533= 5.1.3.2578
Quts HeroOperating system
Affected:= h5.1.0.2409= h5.1.0.2424= h5.1.0.2453= h5.1.0.2466= h5.1.1.2488= h5.1.2.2534= h5.1.3.2578
QutscloudOperating system
Affected:= c5.1.0.2498

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
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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 QTS version
    Log into the QNAP admin web interface and navigate to Control Panel > System > Firmware Update, or run the command 'getsysinfo' via SSH to retrieve the firmware version.
    Affected if The installed QTS version is one of: 5.1.0.2348, 5.1.0.2399, 5.1.0.2418, 5.1.0.2444, 5.1.0.2466, 5.1.1.2491, 5.1.2.2533, or 5.1.3.2578
  2. Check QuTS hero version
    Log into the QuTS hero admin web interface and navigate to Control Panel > System > Firmware Update, or run the command 'getsysinfo' via SSH to retrieve the firmware version.
    Affected if The installed QuTS hero version is one of: h5.1.0.2409, h5.1.0.2424, h5.1.0.2453, h5.1.0.2466, h5.1.1.2488, h5.1.2.2534, or h5.1.3.2578
  3. Check QuTScloud version
    Access the QuTScloud device via SSH and run 'getsysinfo' or check the version through the cloud management portal.
    Affected if The installed QuTScloud version is c5.1.0.2498

A system is affected if it is running any of the specific QTS, QuTS hero, or QuTScloud versions listed in the affected products and versions.

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
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Organizations should update affected QNAP devices to the fixed versions: QTS 5.1.3.2578 build 20231110, QuTS hero h5.1.3.2578 build 20231110, or QuTScloud c5.1.5.2651 and later.

Recommended fix High confidence

QTS 5.1.3.2578 (build 20231110 or later) | QuTS hero h5.1.3.2578 (build 20231110 or later) | QuTScloud c5.1.5.2651 or later

  1. 1. Log into the QNAP NAS management interface (QTS, QuTS hero, or QuTScloud).
  2. 2. Navigate to Control Panel > System > Firmware Update.
  3. 3. Check the current firmware version to confirm it matches one of the affected versions listed.
  4. 4. Click 'Check for Update' to find available updates.
  5. 5. Select and install QTS 5.1.3.2578 (build 20231110 or later), QuTS hero h5.1.3.2578 (build 20231110 or later), or QuTScloud c5.1.5.2651 (or later) depending on your system.
  6. 6. Allow the update to complete and the system to reboot.
  7. 7. After reboot, verify the firmware version has been updated to a fixed release.
Caveat QNAP firmware updates typically require system reboot; ensure data operations are not in progress and consider scheduling during maintenance window

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

Fix this in Qts Scoped from the published advisory
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
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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-2023-39303 in production — separate from our analysis above.

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What this is

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What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
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  • No spam, self-promotion, credentials, or personal data