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Qvr EliteApplication · Qnap

CVE-2021-38692

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 QVR Elite, QVR Pro, and QVR Guard allows remote attackers to execute arbitrary code via overflowing a stack-allocated buffer. This is a classic memory corruption vulnerability where input exceeding buffer boundaries overwrites adjacent stack memory, potentially hijacking execution flow.

MitigationUpdate to the patched versions (QVR Elite 2.1.4.0 or later; QVR Pro/QVR Guard 2.1.3.0 or later) for the applicable QTS/QuTS hero firmware. Apply network segmentation and restrict access to surveillance interfaces as compensating controls until patching is possible.

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. Verify if QVR surveillance product is installed
    Log into QNAP QTS/QuTS hero admin interface and navigate to App Center, or run 'ls -la /share/CACHEDEV1_DATA/.qpkg/QVR' via SSH to check for QVR package directories
    Affected if No QVR package directory exists - the vulnerability does not apply
  2. Identify which QVR product is running
    Check the installed applications via QTS App Center, or run 'cat /etc/config/qpkg.conf | grep -i qvr' to list QVR-related packages
    Affected if The installed product is not QVR Elite, QVR Pro, or QVR Guard
  3. Check installed QVR Elite version
    In QTS App Center click on QVR Elite and view version details, or run '/opt/QVR/bin/qvrelite -v' via SSH if available
    Affected if Version is below 2.1.4.0 (e.g., 2.1.3.0 or earlier)
  4. Check installed QVR Pro version
    In QTS App Center click on QVR Pro and view version details, or run '/opt/QVRPro/bin/qvrpro -v' via SSH if available
    Affected if Version is below 2.1.3.0 (e.g., 2.1.2.0 or earlier)
  5. Check installed QVR Guard version
    In QTS App Center click on QVR Guard and view version details, or run '/opt/QVRGuard/bin/qvrguard -v' via SSH if available
    Affected if Version is below 2.1.3.0 (e.g., 2.1.2.0 or earlier)

If any QVR product (Elite, Pro, or Guard) is installed with a version below its respective threshold (2.1.4.0 for Elite, 2.1.3.0 for Pro/Guard), the system is affected by 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 2.1.3.0 / 2.1.4.0 or later
Fixed in 2.1.3.02.1.4.0
Interim mitigation

Update to the patched versions (QVR Elite 2.1.4.0 or later; QVR Pro/QVR Guard 2.1.3.0 or later) for the applicable QTS/QuTS hero firmware. Apply network segmentation and restrict access to surveillance interfaces as compensating controls until patching is possible.

Recommended fix High confidence

QVR Elite 2.1.4.0+ | QVR Pro 2.1.3.0+ | QVR Guard 2.1.3.0+

  1. 1. Identify which QVR product is running on the QNAP device (QVR Elite, QVR Pro, or QVR Guard)
  2. 2. Access the QNAP admin console and navigate to the QVR application settings
  3. 3. Check the current version of the installed QVR product
  4. 4. For QVR Elite: Upgrade to version 2.1.4.0 or later
  5. 5. For QVR Pro: Upgrade to version 2.1.3.0 or later
  6. 6. For QVR Guard: Upgrade to version 2.1.3.0 or later
  7. 7. Verify the upgrade was successful and the new version is running
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
  • Implementation3.0 h
  • Testing3.0 h
  • Review / QA2.0 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-2021-38692 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