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QtsOperating system · Qnap

CVE-2018-19942

MEDIUM · 6.1 CVSS v3.1 Published 2021-04-16
Fix available
A fix is available. Upgrade to 4.2.6 / 4.3.6 or later.
See remediation →
68/100
Remediation priority · Elevated
Remotely reachable No privileges

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 cross-site scripting (XSS) vulnerability has been reported to affect earlier versions of File Station. If exploited, this vulnerability allows remote attackers to inject malicious code. We have already fixed this vulnerability in the following versions: QTS 4.5.2.1566 build 20210202 (and later) QTS 4.5.1.1456 build 20201015 (and later) QTS 4.3.6.1446 build 20200929 (and later) QTS 4.3.4.1463 build 20201006 (and later) QTS 4.3.3.1432 build 20201006 (and later) QTS 4.2.6 build 20210327 (and later) QuTS hero h4.5.1.1472 build 20201031 (and later) QuTScloud c4.5.4.1601 build 20210309 (and later) QuTScloud c4.5.3.1454 build 20201013 (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

Cross-site scripting (XSS) vulnerability in File Station component of QNAP QTS and related NAS firmware allows remote attackers to inject malicious JavaScript or HTML into the web interface via unsanitized input.

MitigationUpgrade QNAP firmware to the specified fixed versions (QTS 4.5.2.1566+, 4.5.1.1456+, 4.3.6.1446+, 4.3.4.1463+, 4.3.3.1432+, 4.2.6+; QuTS hero h4.5.1.1472+; QuTScloud c4.5.4.1601+ or c4.5.3.1454+) or disable File Station if upgrade is not feasible.

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:< 4.2.6>= 4.3.5, < 4.3.6>= 4.4.0, < 4.5.1= 4.2.6= 4.3.3= 4.3.3.0095= 4.3.3.0096= 4.3.3.0136= 4.3.3.0154= 4.3.3.0174= 4.3.3.0188= 4.3.3.0210
Quts HeroOperating system
Affected:< h4.5.1= h4.5.1
QutscloudOperating system
Affected:< c4.5.3= c4.5.3= c4.5.4

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
Required
Scope
Changed
Confidentiality
Low
Integrity
Low
Availability
None

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

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 your QNAP firmware type
    Log into the QNAP admin interface and locate the firmware information, typically shown on the dashboard or in System Settings > Firmware Update. Identify whether the system runs QTS, QuTS Hero, or QuTScloud.
    Affected if The firmware type is QTS, QuTS Hero, or QuTScloud (any of these are potentially affected)
  2. Check the installed firmware version
    View the firmware version number in the admin interface. QTS versions follow patterns like 4.2.x, 4.3.x, 4.4.x, 4.5.x. QuTS Hero versions start with h (e.g., h4.5.1). QuTScloud versions start with c (e.g., c4.5.3).
    Affected if The installed version falls within any of these ranges: QTS < 4.2.6; QTS >= 4.3.5 and < 4.3.6; QTS >= 4.4.0 and < 4.5.1; QTS = 4.2.6; QTS = 4.3.3; specific 4.3.3 subversions (0095, 0096, 0136, 0154, 0174, 0188, 0210); QuTS Hero < h4.5.1 or = h4.5.1; QuTScloud < c4.5.3, = c4.5.3, or = c4.5.4
  3. Confirm File Station is enabled
    In the QNAP admin interface, navigate to the File Station application (typically listed under Applications or accessible directly). Verify whether File Station is installed and accessible.
    Affected if File Station is installed and accessible on the NAS (the vulnerability only affects systems with File Station enabled)

You are affected if your QNAP NAS runs QTS, QuTS Hero, or QuTScloud with a version matching the affected ranges AND File Station is enabled and accessible.

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.

From vendor data
Upgrade available Upgrade to 4.2.6 / 4.3.6 / 4.5.1 or later
Fixed in 4.2.64.3.64.5.1
Interim mitigation

Upgrade QNAP firmware to the specified fixed versions (QTS 4.5.2.1566+, 4.5.1.1456+, 4.3.6.1446+, 4.3.4.1463+, 4.3.3.1432+, 4.2.6+; QuTS hero h4.5.1.1472+; QuTScloud c4.5.4.1601+ or c4.5.3.1454+) or disable File Station if upgrade is not feasible.

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-2018-19942 in production — separate from our analysis above.

No notes yet

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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