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Weekly Signal
Live intelligence Updated 21 Aug 2026 · 22:11 UTC

QNAP · QNAP Network-Attached Storage (NAS), QTS, Quts Hero

CVE-2020-2509

QNAP Network-Attached Storage (NAS) Command Injection Vulnerability

Recommended action

Validate affected assets and exposure now, then remediate on an accelerated schedule. Vendor advisory from www.qnap.com

View response plan
CVSS9.8
EPSS33.4%
KEVYes
ExploitationConfirmed exploitation
RemediationNot yet verified ↓

Assessment

Why it matters

CISA lists this vulnerability as known to be exploited; exploitation is confirmed; EPSS is 33.4%; technical severity is CVSS 9.8.

A command injection vulnerability has been reported to affect QTS and QuTS hero. If exploited, this vulnerability allows attackers to execute arbitrary commands in a compromised application. We have already fixed this vulnerability in the following versions: QTS 4.5.2.1566 Build 20210202 and later QTS 4.5.1.1495 Build 20201123 and later QTS 4.3.6.1620 Build 20210322 and later QTS 4.3.4.1632 Build 20210324 and later QTS 4.3.3.1624 Build 20210416 and later QTS 4.2.6 Build 20210327 and later QuTS hero h4.5.1.1491 build 20201119 and later

Who should care

  • Teams operating QNAP Network-Attached Storage (NAS), QTS, Quts Hero
  • Vulnerability and exposure management teams
  • Security operations teams monitoring exploitation activity

Response plan

What I would do

  1. Confirm whether QNAP Network-Attached Storage (NAS), QTS, Quts Hero is present in the environment.
  2. Identify affected versions and establish whether vulnerable services are exposed or reachable.
  3. Vendor advisory from www.qnap.com
  4. Review relevant security telemetry for evidence of attempted or successful exploitation.
  5. Document the remediation decision and track it to verified completion.

Treatment intelligence

Remediation intelligence

Not yet verified

Vendor sources are listed before government and third-party guidance. Confirm product applicability and change prerequisites before deployment.

Verification noteAutomated link verification has not completed for this guidance yet.

Technical details

CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CWE
CWE-77
Affected versions
QNAP QNAP Network-Attached Storage (NAS); QNAP QTS (End Excluding 4.2.6 | Start Including 4.3.5, End Excluding 4.3.6 | Start Including 4.4.0, End Excluding 4.5.1 | Version 4.2.6); QNAP Quts Hero (End Excluding h4.5.1 | Version h4.5.1 | Version h4.5.1.1472)
Fixed versions
QNAP QTS (Fixed from 4.2.6, 4.3.6, 4.5.1); QNAP Quts Hero (Fixed from h4.5.1)
Published
17 April 2021
Attack vector
Network
Privileges required
None
User interaction
None

Signal timeline

  1. CVE published
  2. Added to CISA KEV
  3. Latest EPSS score: 33.4%
  4. Signal calculated at 76

External references

Live public intelligence This assessment combines public-source evidence. Validate the affected product, version and exposure against your own environment before making a risk decision.