Raw vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:NCVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.
Summary
CVE-2018-19953 is a medium-severity Cross-site Scripting (CWE-79) vulnerability in Qnap Qts. Its CVSS base score is 6.1 (Medium).
Operationally, exploitation aligns with the MITRE ATT&CK technique Junk Data (T1001.001); ranked in the top 2% 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.
This cross-site scripting vulnerability, tracked as CVE-2018-19953 and assigned CWE-79 and CWE-80, affects multiple versions of QNAP QTS network-attached storage firmware. Successful exploitation enables remote attackers to inject malicious code into affected systems, as reflected in its CVSS 3.1 score of 6.1 with network attack vector, low complexity, no required privileges, and required user interaction.
An unauthenticated remote attacker can exploit the flaw by crafting a malicious link or input that a user interacts with, resulting in injected script execution that impacts confidentiality and integrity within a changed scope while leaving availability unaffected.
QNAP addressed the issue through updated builds including QTS 4.4.2.1231 (20200302), 4.4.1.1201 (20200130), 4.3.6.1218 (20200214), 4.3.4.1190 (20200107), 4.3.3.1161 (20200109), and 4.2.6 (20200109), as detailed in security advisory QSA-20-01. The vulnerability appears in the CISA Known Exploited Vulnerabilities catalog, indicating confirmed real-world exploitation activity.
OWASP Top 10 for Web (2025)
EU & UK References
- 🇪🇺 ENISA EUVD: EUVD-2018-11624
Vulnerability Data
If exploited, this cross-site scripting vulnerability could allow remote attackers to inject malicious code. QNAP has already fixed the issue in the following QTS versions. QTS 4.4.2.1231 on build 20200302; QTS 4.4.1.1201 on build 20200130; QTS 4.3.6.1218 on build 20200214;…
more
QTS 4.3.4.1190 on build 20200107; QTS 4.3.3.1161 on build 20200109; QTS 4.2.6 on build 20200109.
- 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.
A.5.6 only promotes membership in groups to improve knowledge, receive alerts, and share information; it performs no action that stops XSS exploitation (or even the underlying neutralization defect) and is a pure dependency for other controls per the owner's labeling rule.