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Vulnerabilities/CVE-2018-19943Public Intelligence Dossier
Source: qnap · Limited verification•Last verified: •Collection Degraded
CVE-2018-19943ListedHIGH (raw)CVSS 8.0CWE-79

If exploited, this cross-site scripting vulnerability could allow remote attackers to inject malicious code

Published: 28 Oct 2020•Last updated: 13 Aug 2026, 10:47 AM IST•Source identifier: security@qnapsecurity.com.tw
Dossier completeness: source-provided sections 3 / 3 · rule guidance available. Missing source facts count as incomplete.
Official source
CISA KEV catalog
Listed
Added24 May 2022
Due14 Jun 2022
RansomwareKnown
CVSS score
8.0HIGH (raw)
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:H
Metric sourcesecurity@qnapsecurity.com.tw
EPSS probability
22.7%0.227
Percentile98th
Weakness type
CWE-79
CWE-80
Remediation
Patch status unknown
No fixed version or KB recorded

Why It Matters

Analysis dossier

Why It Matters

If exploited, this cross-site scripting vulnerability could allow remote attackers to inject malicious code. QNAP has already fixed these issues in the following QTS versions. QTS 4.4.2.1270 build 20200410 and later QTS 4.4.1.1261 build 20200330 and later QTS 4.3.6.1263 build 20200330 and later QTS 4.3.4.1282 build 20200408 and later QTS 4.3.3.1252 build 20200409 and later QTS 4.2.6 build 20200421 and later

SOC priority

Immediate Attention

Actively exploited (source statement)

Yes

Publicly disclosed

Unknown

Risk basis: CISA KEV exploitation signal; HIGH severity; Source-confirmed exploitation or CISA KEV/ransomware metadata

Affected Products & Remediation

1 source-backed product
Affected products and versions (source)
  • qnap qts · < 4.2.6; >= 4.3.1.0013 < 4.3.3.1252; >= 4.3.4 < 4.3.4.1282; >= 4.3.6 < 4.3.6.1263; >= 4.4.0 < 4.4.1.1261; >= 4.4.2 < 4.4.2.1270; 4.2.6 · NVD CPE · Source
Recorded patch / KBNot provided by source

Vendor or catalog guidance (source)

  • CISA KEV: Apply updates per vendor instructions.

Known exploitation (source facts)

Only what a source states. Unknown means no source has said either way; it is not "not exploited".

CISA KEV
Listed
Exploited (source statement)
Yes
Publicly disclosed (source)
Unknown

CISA required action: Apply updates per vendor instructions.

Suggested hunting (rule-based inference)

SecOps Signal recommendation (rule-based inference). These steps are hunting hypotheses from the vulnerability class; they do not state or imply that exploitation occurred here or anywhere.

Matched kev-network-exposure (CVSS AV:N, CISA KEV Listed); cross-site-scripting (CWE-79)

Exposure

  1. Identify assets with the exact CVE and confirm the affected product/version against the advisory.Telemetry: DeviceTvmSoftwareVulnerabilities · KEV listing raises urgency, but inventory is needed to establish local exposure. · Rule kev-network-exposure
  2. Identify the affected web component and source-stated version range.Telemetry: Application inventory · The weakness class does not identify local deployment. · Rule cross-site-scripting

Exploitation evidence

  1. Review relevant edge or application access logs for unusual requests around the advisory window.Telemetry: CommonSecurityLog · Log review is a hunting hypothesis; KEV listing alone does not show local exploitation. · Rule kev-network-exposure
Show more (2)

Exploitation evidence

  1. Review suspicious script-bearing requests to the affected endpoint.Telemetry: Application access logs · Requests are leads, not evidence that a user session was compromised. · Rule cross-site-scripting

Response

  1. Recheck the affected assets after the source-stated mitigation or update is applied.Telemetry: DeviceTvmSoftwareVulnerabilities · A follow-up inventory check verifies local remediation. · Rule kev-network-exposure

CISA KEV Record

Catalog entry
24 May 2022
Required action due
14 Jun 2022
Known ransomware use
Known

Apply updates per vendor instructions.

Change History & Source Data

— No recorded material change

CNA / source
security@qnapsecurity.com.tw
Record status · verification
UPDATED · CISA KEV confirmed
CPE
cpe:2.3:o:qnap:qts:*:*:*:*:*:*:*:*, cpe:2.3:o:qnap:qts:4.2.6:-:*:*:*:*:*:*, cpe:2.3:o:qnap:qts:4.2.6:build_20170517:*:*:*:*:*:*, cpe:2.3:o:qnap:qts:4.2.6:build_20190322:*:*:*:*:*:*, cpe:2.3:o:qnap:qts:4.2.6:build_20190730:*:*:*:*:*:*, cpe:2.3:o:qnap:qts:4.2.6:build_20190921:*:*:*:*:*:*, cpe:2.3:o:qnap:qts:4.2.6:build_20191107:*:*:*:*:*:*, cpe:2.3:o:qnap:qts:4.2.6:build_20200109:*:*:*:*:*:*, cpe:2.3:o:qnap:qts:4.2.6:build_20200421:*:*:*:*:*:*, cpe:2.3:o:qnap:qts:4.2.6:build_20200611:*:*:*:*:*:*

Evidence & Provenance

4 public sources
CISA KEV CatalogAdded 2022-05-24qnap.comSource recordnvd.nist.govSource recordcisa.govSource record

Linked by the query's stored exact CVE association. Review required tables and validation status before use.

Detection Hunting Query
Target: DeviceTvmSoftwareVulnerabilities•Defender XDR
Detect endpoints exposed to CVE-2018-19943
Purpose: Exposure assessment (Category: Exposure Check)Why linked: Query metadata names CVE-2018-19943
DeviceTvmSoftwareVulnerabilities| where CveId == "CVE-2018-19943"| project DeviceId, DeviceName, OSPlatform, OSVersion, SoftwareVendor, SoftwareName, SoftwareVersion, CveId, VulnerabilitySeverityLevel, RecommendedSecurityUpdate, RecommendedSecurityUpdateId| sort by VulnerabilitySeverityLevel desc
Schema Checked · Not runtime validatedSource: SecOps Signal deterministic template · Limited verificationStatic screening: Passed structure and schema checks; tenant execution is not verified.
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Correlated briefings

SecOps Signal surfaces public advisory facts only. A missing value means the source has not published it, not that your environment is unaffected. No tenant inventory is connected.