CVE intelligence and bounded remediation

CVE-2021-44053 — A cross-site scripting (XSS) vulnerability has been reported to affect QNAP device running QTS, QuTS hero and QuTScloud

Medium CVSS 6.1

A cross-site scripting (XSS) vulnerability has been reported to affect QNAP device running QTS, QuTS hero and QuTScloud. If exploited, this vulnerability allows remote attackers to inject malicious code. We have already fixed this vulnerability in the following versions of QTS, QuTS hero and QuTScloud: QTS 4.5.4.1991 build 20220329 and later QTS 5.0.0.1986 build 20220324 and later QuTS hero h5.0.0.1986 build 20220324 and later QuTS hero h4.5.4.1971 build 20220310 and later QuTScloud c5.0.1.1949 and later

Severity
Medium
CVSS
6.1 (3.1)
Published
2022-05-05
CISA KEV
Not currently listed
Ecosystem
software/application
Weaknesses
CWE-79

Affected products

  • qnap / qts
  • qnap / qts / 4.2.6

Showing 2 representative product identities from 19 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Cross-site scripting and unsafe browser output

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace reflected, stored, and DOM-derived untrusted values into HTML, attributes, URLs, styles, scripts, and client-side template sinks.
  • Identify affected origins, authenticated user roles, sensitive browser capabilities, and where content is shared across tenants.
  • Review framework escaping, rich-text sanitization, legacy templates, and client-side rendering paths.

Remediate safely

  • Use context-aware framework output encoding and safe DOM APIs; keep untrusted data out of executable contexts.
  • Sanitize intentionally supported markup with a maintained allowlist policy and validate URLs and attributes separately.
  • Update affected rendering components and add tests for every output context using inert sentinel markup.

Authoritative sources

Complete CVE record and remediation plan

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