CVE intelligence and bounded remediation

CVE-2021-24563 — Frontend Uploader Project Frontend Uploader security vulnerability

Medium CVSS 6.1

The Frontend Uploader WordPress plugin through 1.3.2 does not prevent HTML files from being uploaded via its form, allowing unauthenticated user to upload a malicious HTML file containing JavaScript for example, which will be triggered when someone access the file directly

Severity
Medium
CVSS
6.1 (3.1)
Published
2021-10-11
CISA KEV
Not currently listed
Ecosystem
php/wordpress
Weaknesses
CWE-79

Affected products

  • frontend_uploader_project / frontend_uploader

Matched remediation archetype

Cross-site scripting and unsafe browser output

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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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