Formidable Form Builder <= 2.0.21 - Missing Authorization Checks

2016-02-16 00:00
James Golovich

Strategic Overview

Status
Patched in 2.0.22
Affected Plugin
Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes & More
Affected Version
<= 2.0.21
CVSS
9.1Critical
Weakness type
CWE-284 · Improper Access Control
CVE
CVE pending
View all Formidable Forms – WordPress Form Builder for Contact Forms, Calculators, Quizzes & More vulnerabilities

At a glance

This record tracks a critical-severity Improper Access Control vulnerability in the Formidable Forms WordPress plugin, affecting versions <= 2.0.21. It carries a CVSS score of 9.1 (reachable over the network; low attack complexity; high confidentiality, integrity impact). Exploitation requires no authentication. The issue is fixed in version 2.0.22; sites on affected versions should update now. Disclosed February 2016, reported by James Golovich.

Vulnerability Overview

The Formidable Form Builder plugin for WordPress is vulnerable to authorization bypass in versions up to, and including, 2.0.21. This is due to missing nonce and capability checks on the 'frm_fill_licenses' and 'frm_ajax' AJAX actions. This makes it possible for unauthenticated attackers to access leaked nonces and modify form fields.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity.

CWE-284: Improper Access Control

Formidable Forms <= 2.0.21 carries this weakness at frm_fill_licenses, and reaching it takes a caller who can reach the endpoint. Improper access control means the code decides what a caller may do using something other than their actual permissions, so the decision can be wrong without any check appearing to be missing.

Whoever can shape the request decides the answer, so the protected action runs for callers the code never meant to allow. For Formidable Forms the fix is 2.0.22: builds <= 2.0.21 are affected, anything from 2.0.22 onward is not.

Remediation

Update to version 2.0.22, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Formidable Forms 2.0.22 closes this, and updating the plugin is the step that ends it.

  • Login Security
  • Alerts

External References

https://www.wordfence.com/threat-intel/vulnerabilities/id/faed1198-b8c4-46b1-b6a6-5fc35cd7bdf8

Related records

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