CVE-2018-19953 — QNAP NAS File Station Cross-Site Scripting Vulnerability

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; QTS 4

01What is this vulnerability?

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; QTS 4.3.4.1190 on build 20200107; QTS 4.3.3.1161 on build 20200109; QTS 4.2.6 on build 20200109.

02Affected products

Vendor	Product	Versions
QNAP Systems Inc.	QTS	unspecified
QNAP Systems Inc.	QTS	unspecified
QNAP Systems Inc.	QTS	unspecified
QNAP Systems Inc.	QTS	unspecified
QNAP Systems Inc.	QTS	unspecified, unspecified

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2022-05-24. Ransomware use: Known.

04Recommended remediation

• Patch to a fixed version listed in the vendor advisory (see references below).
• Mitigate with WAF rules, network egress filters, or feature flags where the patch is not yet available.
• Hunt historical logs for exploitation indicators — see Detection signatures below.

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

Open in Sigma generator →

07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

• Published: 2020-10-28T17:55:18.000Z
• Last modified: 2025-10-21T23:35:33.900Z
• Added to CISA KEV: 2022-05-24
• BOD 22-01 due: 2022-06-14

09References

• www.qnap.com — https://www.qnap.com/zh-tw/security-advisory/qsa-20-01