dbcve.org
QvrApplication · Qnap

CVE-2021-34348

CRITICAL · 9.8 CVSS v3.1 Published 2021-09-27
Fix available
A fix is available. Upgrade to 5.1.5 or later.
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
A 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 · moderate confidence

A command injection vulnerability in QNAP QVR allows remote attackers to execute arbitrary commands on affected devices. The vulnerability stems from improper input validation that allows malicious input to be passed to system command execution functions.

MitigationUpdate QVR to version 5.1.5 build 20210803 or later. Additionally, restrict network access to QVR management interfaces and implement network segmentation to reduce exposure to external attackers.

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
QvrApplication
Affected:< 5.1.5

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. Confirm QVR is installed
    Check if QNAP QVR software is running on the device by accessing the QVR management interface or reviewing installed applications on the QNAP system.
    Affected if QVR software is present on the device.
  2. Locate the QVR version
    Access the QVR management console and navigate to System Settings > System Information, or check the QNAP App Center for the installed QVR version number.
    Affected if Unable to locate version information indicates potential QVR installation but version cannot be verified.
  3. Compare installed version against vulnerable range
    Compare the identified QVR version to the affected range: any version below 5.1.5 (such as 5.1.4, 5.1.3, 5.0.x, etc.) is within the vulnerable range.
    Affected if The installed QVR version is below 5.1.5.
  4. Verify QVR management interface exposure
    Review network configuration to determine if the QVR management interface (typically ports 80/443 or 8080/8081) is accessible from untrusted networks or the internet.
    Affected if The QVR management interface is exposed to external networks without proper access controls.

The environment is affected if QNAP QVR is installed with a version lower than 5.1.5 and the management interface is network-accessible.

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 5.1.5 or later
Fixed in 5.1.5
Interim mitigation

Update QVR to version 5.1.5 build 20210803 or later. Additionally, restrict network access to QVR management interfaces and implement network segmentation to reduce exposure to external attackers.

Recommended fix High confidence

QVR 5.1.5 build 20210803 or later

  1. 1. Log into the QNAP QVR management interface
  2. 2. Navigate to the QVR settings or system management section
  3. 3. Check the current QVR version installed (typically found in System Information or About section)
  4. 4. If the installed version is earlier than QVR 5.1.5 build 20210803, initiate an upgrade
  5. 5. Download and install QVR version 5.1.5 build 20210803 or a later stable release from QNAP's official download center
  6. 6. After installation, verify the new version is correctly installed by checking System Information > QVR version
  7. 7. Test that the QVR service is functioning normally after the upgrade
Caveat Standard QVR upgrade - ensure adequate backup of recording data and configuration before upgrading; test in staging if possible

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

Fix this in Qvr Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,120
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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-2021-34348 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