CVE intelligence and bounded remediation

CVE-2021-24229 — Patreon Patreon Wordpress security vulnerability

Critical CVSS 9.6

The Jetpack Scan team identified a Reflected Cross-Site Scripting via the patreon_save_attachment_patreon_level AJAX action of the Patreon WordPress plugin before 1.7.2. This AJAX hook is used to update the pledge level required by Patreon subscribers to access a given attachment. This action is accessible for user accounts with the ‘manage_options’ privilege (i.e.., only administrators). Unfortunately, one of the parameters used in this AJAX endpoint is not sanitized before being printed back to the user, so the risk it represents is the same as the previous XSS vulnerability.

Severity
Critical
CVSS
9.6 (3.1)
Published
2021-04-12
CISA KEV
Not currently listed
Ecosystem
php/wordpress
Weaknesses
CWE-79

Affected products

  • patreon / patreon_wordpress

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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