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Qvr EliteApplication · Qnap

CVE-2021-38690

CRITICAL · 9.8 CVSS v3.1 Published 2022-01-14
Fix available
A fix is available. Upgrade to 2.1.3.0 / 2.1.4.0 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 stack buffer overflow vulnerability has been reported to affect QNAP device running QVR Elite, QVR Pro, QVR Guard. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of QVR Elite, QVR Pro, QVR Guard: QuTS hero h5.0.0: QVR Elite 2.1.4.0 (2021/12/06) and later QuTS hero h4.5.4: QVR Elite 2.1.4.0 (2021/12/06) and later QTS 5.0.0: QVR Elite 2.1.4.0 (2021/12/06) and later QTS 4.5.4: QVR Elite 2.1.4.0 (2021/12/06) and later QTS 4.5.4: QVR Pro 2.1.3.0 (2021/12/06) and later QTS 5.0.0: QVR Pro 2.1.3.0 (2021/12/06) and later QTS 4.5.4: QVR Guard 2.1.3.0 (2021/12/06) and later QTS 5.0.0: QVR Guard 2.1.3.0 (2021/12/06) 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 stack buffer overflow vulnerability in QNAP devices running QVR Elite, QVR Pro, and QVR Guard allows remote attackers to execute arbitrary code due to improper bounds checking when processing input. This critical vulnerability (CVSS 9.8) can be exploited without authentication.

MitigationUpdate QVR software to the specified fixed versions (QVR Elite 2.1.4.0 or later for the listed platforms, QVR Pro/QVR Guard 2.1.3.0 or later) released on 2021/12/06 to remediate 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
Qvr EliteApplication
Affected:< 2.1.4.0
Qvr GuardApplication
Affected:< 2.1.3.0
Qvr ProApplication
Affected:< 2.1.3.0

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 if QVR software is installed
    Log into the QNAP admin interface (QTS/QuTS hero) and navigate to App Center or the QVR section to verify if QVR Elite, QVR Pro, or QVR Guard is installed.
    Affected if Any of these three applications (QVR Elite, QVR Pro, or QVR Guard) are present on the device.
  2. Identify installed QVR version
    In the QNAP admin interface, locate the installed version number for the detected QVR application. This is typically visible in App Center under the application details or in the QVR system settings.
    Affected if The displayed version number is lower than 2.1.4.0 for QVR Elite, or lower than 2.1.3.0 for QVR Pro or QVR Guard.
  3. Confirm QVR Elite version range
    If QVR Elite is installed, verify the exact version by checking the package details in App Center or the QVR Elite settings panel. Compare the version against the affected range.
    Affected if The installed QVR Elite version is less than 2.1.4.0.
  4. Confirm QVR Pro version range
    If QVR Pro is installed, verify the exact version by checking the package details in App Center or the QVR Pro settings panel. Compare the version against the affected range.
    Affected if The installed QVR Pro version is less than 2.1.3.0.
  5. Confirm QVR Guard version range
    If QVR Guard is installed, verify the exact version by checking the package details in App Center or the QVR Guard settings panel. Compare the version against the affected range.
    Affected if The installed QVR Guard version is less than 2.1.3.0.

The device is affected if QVR Elite version is below 2.1.4.0, or QVR Pro or QVR Guard version is below 2.1.3.0.

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 2.1.3.0 / 2.1.4.0 or later
Fixed in 2.1.3.02.1.4.0
Interim mitigation

Update QVR software to the specified fixed versions (QVR Elite 2.1.4.0 or later for the listed platforms, QVR Pro/QVR Guard 2.1.3.0 or later) released on 2021/12/06 to remediate this vulnerability.

Recommended fix High confidence

QVR Elite 2.1.4.0 | QVR Pro 2.1.3.0 | QVR Guard 2.1.3.0 (all released 2021/12/06)

  1. 1. Identify which QNAP surveillance application is installed: QVR Elite, QVR Pro, or QVR Guard
  2. 2. Check the current version of the installed QVR application via the QNAP admin interface (QTS/QuTS hero)
  3. 3. Verify the QTS or QuTS hero firmware version running on the device
  4. 4. For QVR Elite: Upgrade to version 2.1.4.0 or later (released 2021/12/06)
  5. 5. For QVR Pro: Upgrade to version 2.1.3.0 or later (released 2021/12/06)
  6. 6. For QVR Guard: Upgrade to version 2.1.3.0 or later (released 2021/12/06)
  7. 7. Verify successful installation by confirming the new version number in the QNAP admin interface
  8. 8. Ensure the QTS/QuTS hero firmware is updated to a supported version (QTS 4.5.4, QTS 5.0.0, QuTS hero h4.5.4, or QuTS hero h5.0.0) as listed in the official fix
Caveat Review QNAP release notes for any configuration or feature changes between versions before upgrading

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

Fix this in Qvr Elite 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-2021-38690 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