Formidable Forms <= 6.3 - Authenticated (Subscriber+) Arbitrary Plugin Installation and Activation

Missing Authorization
CVE CVE-2023-2877
CVSS 6.5 (Medium)
Publicly Published May 31, 2023
Last Updated January 22, 2024
Researcher Alex Sanford


The Formidable Forms plugin for WordPress is vulnerable to unauthorized arbitrary plugin installation and activation due to a missing capability check on the screen_page() and can_install_addon_api() functions in versions up to, and including, 6.3. This makes it possible for authenticated attackers, with minimal permissions such as subscribers to retrieve a valid token from the welcome page, and then subsequently install and activate arbitrary plugins onto the site utilizing that key. This can easily be leveraged by attackers to achieve remote code execution as they simply need to install another plugin with a vulnerability or functionality that will aid in further exploitation.

Wordfence blocked 1,743 attacks targeting this vulnerability in the past 24 hours.



Vulnerability Details for Formidable Forms – Contact Form Plugin, Survey, Quiz, Payment, Calculator Form & Custom Form Builder

Software Type Plugin
Software Slug formidable (view on
Patched? Yes
Remediation Update to version 6.3.1, or a newer patched version
Affected Version
  • < 6.3.1
Patched Version
  • 6.3.1

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