CVE-2021-34346
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 stack buffer overflow vulnerability has been reported to affect QNAP device running NVR Storage Expansion. If exploited, this vulnerability allows attackers to execute arbitrary code. We have already fixed this vulnerability in the following versions of NVR Storage Expansion: NVR Storage Expansion 1.0.6 ( 2021/08/03 ) 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 confidenceA stack buffer overflow vulnerability in QNAP NVR Storage Expansion allows remote attackers to execute arbitrary code on affected devices. The vulnerability stems from improper bounds checking when processing input on the stack, enabling attackers to overwrite return addresses and inject malicious code.
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< 1.0.6CVSS 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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Confirm QNAP NVR Storage Expansion productAccess the device admin interface or run 'lsusb' or check device model via 'getsysinfo' command to verify the device is specifically the QNAP NVR Storage Expansion modelAffected if The device is not a QNAP NVR Storage Expansion unit, then this CVE does not apply
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Identify the installed firmware versionAccess the QNAP admin web interface (usually at https://<device-ip>) and navigate to System Settings > Firmware Update, or use the QNAP Finder tool to check the firmware versionAffected if The firmware version displayed is below 1.0.6 (for example, 1.0.5, 1.0.4, etc.)
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Verify network accessibility of the deviceCheck if the NVR Storage Expansion device is reachable on the network and note whether it is exposed to untrusted networks or the internetAffected if The device is directly accessible from untrusted networks (e.g., exposed to the internet) and runs an affected firmware version below 1.0.6
The environment is affected if the device is a QNAP NVR Storage Expansion unit running firmware version prior to 1.0.6 and the device is network-accessible to potential attackers.
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 · scoped1.0.6
Update NVR Storage Expansion to version 1.0.6 (released 2021/08/03) or later to remediate the vulnerability. If immediate patching is not possible, restrict network access to the affected NVR systems.
NVR Storage Expansion 1.0.6
- 1. Identify the QNAP NVR Storage Expansion device model
- 2. Download the NVR Storage Expansion firmware version 1.0.6 or later from the official QNAP download center
- 3. Access the QNAP admin interface for the NVR Storage Expansion device
- 4. Navigate to the firmware update section in System Settings
- 5. Upload and install the downloaded firmware (version 1.0.6 or later)
- 6. Verify the firmware installation was successful and the device is running the patched version
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation1.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-34346 — 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-2021-34346 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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- 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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