CVE intelligence and bounded remediation

CVE-2024-3866 — Ninjaforms Ninja Forms security vulnerability

Medium CVSS 6.1

The Ninja Forms Contact Form plugin for WordPress is vulnerable to Reflected Self-Based Cross-Site Scripting via the 'Referer' header in all versions up to, and including, 3.8.15 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link. Successful exploitation of this vulnerability requires "maintenance mode" for a targeted form to be enabled. However, there is no setting available to the attacker or even an administrator-level user to enable this mode. The mode is only enabled during a required update, which is a very short window of time. Additionally, because of the self-based nature of this vulnerability, attackers would have to rely on additional techniques to execute a supplied payload in the context of targeted user.

Severity
Medium
CVSS
6.1 (3.1)
Published
2024-09-25
CISA KEV
Not currently listed
Ecosystem
php/wordpress
Weaknesses
CWE-79

Affected products

  • ninjaforms / ninja_forms

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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