What’s Vulnerable › Vulnerabilities

CVE-2021-24163: Ninja Forms < 3.4.34 - Authenticated SendWP Plugin Installation and Client Secret Key Disclosure

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.4% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2021-04-05 · updated 2026-06-17
• Weakness: CWE-200

Description

The AJAX action, wp_ajax_ninja_forms_sendwp_remote_install_handler, did not have a capability check on it, nor did it have any nonce protection, therefore making it possible for low-level users, such as subscribers, to install and activate the SendWP Ninja Forms Contact Form – The Drag and Drop Form Builder for WordPress WordPress plugin before 3.4.34 and retrieve the client_secret key needed to establish the SendWP connection while also installing the SendWP plugin.

Affected products

• kstover Ninja Forms – The Contact Form Builder That Grows With You: before 3.4.34 — fixed in 3.4.34

How to fix

Upgrade to a fixed version: kstover Ninja Forms – The Contact Form Builder That Grows With You 3.4.34. Check the vendor advisory for mitigations.

References

• https://wpscan.com/vulnerability/55fde9fa-f6cd-4546-bee8-4acc628251c2
• https://www.wordfence.com/blog/2021/02/one-million-sites-affected-four-severe-vulnerabilities-patched-in-ninja-forms/
• https://wpscan.com/vulnerability/55fde9fa-f6cd-4546-bee8-4acc628251c2
• https://www.wordfence.com/blog/2021/02/one-million-sites-affected-four-severe-vulnerabilities-patched-in-ninja-forms/

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