Raw vector
CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:H/A:HSummary
CVE-2018-19943 is a high-severity Cross-site Scripting (CWE-79) vulnerability in Qnap Qts. Its CVSS base score is 8.0 (High).
Operationally, exploitation aligns with the MITRE ATT&CK technique Browser Session Hijacking (T1185); ranked in the top 3% of CVEs by exploit likelihood; CISA has added it to the Known Exploited Vulnerabilities catalog.
Deeper analysis AI-assisted summary
Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.
CVE-2018-19943 is a cross-site scripting vulnerability, tracked under CWE-79 and CWE-80, that affects multiple versions of QNAP QTS prior to the listed fixed builds. Successful exploitation permits remote attackers to inject malicious code into the affected NAS operating system.
An attacker with low privileges can leverage the flaw over the network, though the attack requires high complexity, user interaction, and results in changed scope; the CVSS 3.1 score of 8.0 reflects high impact on confidentiality, integrity, and availability. The vulnerability enables injection of arbitrary scripts that execute in the context of other users or sessions.
QNAP security advisory QSA-20-01 states that the issues have been resolved in QTS 4.4.2.1270 build 20200410 and later, 4.4.1.1261 build 20200330 and later, 4.3.6.1263 build 20200330 and later, 4.3.4.1282 build 20200408 and later, 4.3.3.1252 build 20200409 and later, and 4.2.6 build 20200421 and later. The vulnerability appears in the CISA Known Exploited Vulnerabilities catalog, indicating confirmed real-world exploitation.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2018-11614
Vulnerability Data
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…
more
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
- CWE(s)
- KEV Date Added
- 24 May 2022
Related Threats
MITRE ATT&CK Enterprise Techniques
CVEs Like This One
Affected Assets
Mitigating Controls
Control response
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Likely Mitigating Controls AI
Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.
Penetration testing submits XSS payloads to web applications, detecting cross-site scripting flaws for subsequent remediation.
Validates web inputs to reject script-related content that could produce XSS.
Output validation against expected content can reject or sanitize script content in generated web pages, reducing XSS exploitability.
Mitigating Controls (NIST CSF 2.0) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.
Secure SDLC practices directly target introduction of XSS via coding standards/testing (mostly), yet the single broad outcome leaves many specific neutralization vectors unaddressed (partial).
Patching and EOL replacement can remediate known XSS instances in libraries or frameworks (partial) but do nothing to enforce input neutralization in application code (none).
Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI
Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.
Secure-coding testing and automated code-analysis tools are applied to detect improper neutralization of script-related content during web-page generation.
Knowledge exchange on emerging attack techniques and patches reduces the likelihood that cross-site scripting flaws remain unaddressed in deployed applications.
Operational indicators of compromise for web-application attacks can be incorporated into WAF or input-filtering rules, lowering the likelihood that unsanitized data reaches the browser.
Requiring language-specific secure-coding standards and automated scanning during the SDLC catches missing output encoding or improper neutralization of untrusted data before the software reaches production.
Application security requirements explicitly call for neutralization of script-related HTML tags.
Secure-coding standards, SAST scans and removal of insecure code samples together eliminate the failure to neutralize script content that produces cross-site scripting flaws.