CVE intelligence and bounded remediation

CVE-2018-19945 — A vulnerability has been reported to affect earlier QNAP devices running QTS 4.3.4 to 4.3.6

Critical CVSS 9.1

A vulnerability has been reported to affect earlier QNAP devices running QTS 4.3.4 to 4.3.6. Caused by improper limitations of a pathname to a restricted directory, this vulnerability allows for renaming arbitrary files on the target system, if exploited. QNAP have already fixed this vulnerability in the following versions: QTS 4.3.6.0895 build 20190328 (and later) QTS 4.3.4.0899 build 20190322 (and later) This issue does not affect QTS 4.4.x or QTS 4.5.x.

Severity
Critical
CVSS
9.1 (3.1)
Published
2020-12-31
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-20, CWE-22, CWE-73, CWE-284

Affected products

  • qnap / qts

Showing 1 representative product identities from 2 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Authorization bypass, IDOR, and cross-tenant access

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

Check exposure

  • Map object and action authorization checks across API, UI, batch, import/export, and background-job paths.
  • Identify tenant, ownership, role, and policy boundaries for affected resources and administrative operations.
  • Use synthetic fixtures to compare intended access matrices without accessing another user's real data.

Remediate safely

  • Enforce server-side authorization at each resource access and state transition using the authenticated principal and trusted tenant context.
  • Scope data queries by tenant and ownership; treat client-supplied identifiers, roles, and policy claims as untrusted.
  • Add deny-by-default policy tests for horizontal and vertical access across every affected transport.

Authoritative sources

Complete CVE record and remediation plan

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