CVE intelligence and bounded remediation

CVE-2021-24427 — Boldgrid W3 Total Cache security vulnerability

Medium CVSS 4.8

The W3 Total Cache WordPress plugin before 2.1.3 did not sanitise or escape some of its CDN settings, allowing high privilege users to use JavaScript in them, which will be output in the page, leading to an authenticated Stored Cross-Site Scripting issue

Severity
Medium
CVSS
4.8 (3.1)
Published
2021-07-12
CISA KEV
Not currently listed
Ecosystem
php/wordpress
Weaknesses
CWE-79

Affected products

  • boldgrid / w3_total_cache

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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