CVE-2021-34351
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 · uneditedA command injection vulnerability has been reported to affect QNAP device running QVR. If exploited, this vulnerability could allow remote attackers to run arbitrary commands. We have already fixed this vulnerability in the following versions of QVR: QVR 5.1.5 build 20210803 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 confidenceA command injection vulnerability in QNAP QVR allows remote attackers to execute arbitrary commands on affected devices due to insufficient input validation.
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< 5.1.5CVSS 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 checksWork through these to decide whether this CVE applies to you.
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Verify QVR is installedCheck if QNAP QVR service is running on the device. This can typically be done through the QNAP admin interface under 'App Center' or by checking running services via SSH if available.Affected if QVR software is present on the system and the service is active
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Locate the QVR version informationAccess the QVR management interface and navigate to System Settings > System Information, or check the QNAP NAS firmware version which often includes bundled application versions.Affected if Version information cannot be located or QVR is not listed as an installed application
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Compare installed version against affected rangeDocument the exact version number of QVR installed and compare it to the vulnerable range: any version below 5.1.5 is affected.Affected if The installed QVR version is below 5.1.5 (for example, 5.1.0, 5.0.x, or earlier releases)
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Confirm QVR management interface is accessibleVerify that the QVR web management interface is reachable on the network. This is the attack vector through which the command injection could be exploited.Affected if The QVR management interface is exposed and the QVR version is below 5.1.5
A system is affected if QNAP QVR is installed with any version lower than 5.1.5 and the QVR management interface is network-accessible.
Generated from the published advisory. Verify against your own configuration.
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 · scoped5.1.5
Update QVR to version 5.1.5 build 20210803 or later. If immediate patching is not feasible, restrict network access to the QVR management interface to reduce exposure.
QVR 5.1.5 build 20210803 or later
- Access the QNAP management interface for the affected device
- Navigate to the QVR application settings
- Check the current QVR version to confirm it is below 5.1.5
- Download QVR version 5.1.5 (build 20210803) or later from the official QNAP download center
- Install the updated QVR version following the standard QNAP firmware upgrade procedure
- Reboot the QNAP device if required by the upgrade process
- Verify the installed QVR version is 5.1.5 build 20210803 or later
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation3.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,984.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-34351 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-34351 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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
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