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QtsOperating system · Qnap

CVE-2021-28804

CRITICAL · 9.8 CVSS v3.1 Published 2021-07-01
Fix available
A fix is available. Upgrade to after 4.5.1.1540 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 vulnerabilities have been reported to affect QTS and QuTS hero. If exploited, this vulnerability allows attackers to execute arbitrary commands in a compromised application. This issue affects: QNAP Systems Inc. QTS versions prior to 4.5.1.1540 build 20210107. QNAP Systems Inc. QuTS hero versions prior to h4.5.1.1582 build 20210217.

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

Command injection vulnerability in QNAP QTS and QuTS hero allows attackers to execute arbitrary commands through compromised application input. This stems from insufficient input validation allowing shell command manipulation.

MitigationUpdate QTS to version 4.5.1.1540 build 20210107 or later, and QuTS hero to version h4.5.1.1582 build 20210217 or later 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
QtsOperating system
Affected:<= 4.5.1.1540
Quts HeroOperating system
Affected:<= h4.5.1.1582

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. Identify the QNAP product type
    Access the admin web interface and navigate to Control Panel > System Information > System Status, or run `getconf` via SSH to determine if the system is running QTS or QuTS hero.
    Affected if The product is QNAP QTS or QuTS hero.
  2. Check the QTS firmware version
    In the web interface, go to Control Panel > System Information > System Status and note the firmware version shown (e.g., 4.5.1.1540). Alternatively, run `cat /etc/config/version` via SSH to retrieve the version number.
    Affected if The installed version is QTS and is <= 4.5.1.1540.
  3. Check the QuTS hero firmware version
    In the web interface, go to Control Panel > System Information > System Status and note the firmware version shown (e.g., h4.5.1.1582). Alternatively, run `cat /etc/config/version` via SSH to retrieve the version number.
    Affected if The installed version is QuTS hero and is <= h4.5.1.1582.
  4. Verify the build date if version is ambiguous
    If the version number matches the boundary (4.5.1.1540 or h4.5.1582), check the build date in Control Panel > System Information > System Status. The fixed builds are 20210107 for QTS and 20210217 for QuTS hero.
    Affected if The version is the boundary number but the build date is earlier than the fixed build.

A system is affected if it runs QTS version 4.5.1.1540 or lower, or QuTS hero version h4.5.1.1582 or lower (or at those versions with earlier build dates).

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 a release after 4.5.1.1540
Interim mitigation

Update QTS to version 4.5.1.1540 build 20210107 or later, and QuTS hero to version h4.5.1.1582 build 20210217 or later to remediate this vulnerability.

Recommended fix High confidence

QTS: 4.5.1.1540 build 20210107 or later | QuTS hero: h4.5.1.1582 build 20210217 or later

  1. 1. Log into the QNAP NAS admin interface.
  2. 2. Navigate to Control Panel > System > Firmware Update.
  3. 3. Click 'Check for Update' to see available updates.
  4. 4. For QTS systems: Update to QTS version 4.5.1.1540 (build 20210107) or later.
  5. 5. For QuTS hero systems: Update to QuTS hero version h4.5.1.1582 (build 20210217) or later.
  6. 6. Allow the firmware update to complete and the system to reboot.
  7. 7. After reboot, verify the updated firmware version in Control Panel > System > Firmware Update > Version Information.

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

Fix this in Qts Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing2.0 h
  • Review / QA1.0 h
8.0 hours of engineering $1,420
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Scan for this in your stack

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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-2021-28804 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