CVE intelligence and bounded remediation

CVE-2021-24208 — Themeum Wp Page Builder security vulnerability

Medium CVSS 5.4

The editor of the WP Page Builder WordPress plugin before 1.2.4 allows lower-privileged users to insert unfiltered HTML, including JavaScript, into pages via the “Raw HTML” widget and the “Custom HTML” widgets (though the custom HTML widget requires sending a crafted request - it appears that this widget uses some form of client side validation but not server side validation), all of which are added via the “page_builder_data” parameter when performing the “wppb_page_save” AJAX action. It is also possible to insert malicious JavaScript via the “wppb_page_css” parameter (this can be done by closing out the style tag and opening a script tag) when performing the “wppb_page_save” AJAX action.

Severity
Medium
CVSS
5.4 (3.1)
Published
2021-04-05
CISA KEV
Not currently listed
Ecosystem
php/wordpress
Weaknesses
CWE-79

Affected products

  • themeum / wp_page_builder

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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