Understanding the Threat: Formidable Form Builder Stored XSS
The Formidable Form Builder, a highly popular WordPress plugin relied upon by thousands for creating everything from simple contact forms to complex surveys, was found to harbor a critical security vulnerability. This flaw, officially identified as CVE-2017-20192, is primarily a Stored Cross-Site Scripting (XSS) vulnerability. In simple terms, Stored XSS means that an attacker can embed malicious code, usually JavaScript, directly into your website’s database. When a legitimate user, particularly an administrator, later views content containing this hidden code (like reviewing a submitted form entry), their browser unknowingly executes the attacker’s script. This can lead to serious consequences, such as session hijacking, defacement of the website, or even redirecting users to malicious sites.
A thorough investigation into this vulnerability, including findings from a detailed bug bounty report by Klikki, revealed that the risks extended far beyond just Stored XSS. The analysis uncovered several other serious vulnerabilities within the plugin. These included a significant SQL Injection flaw, which could grant an attacker complete access to your website’s database, allowing them to steal sensitive information like user credentials, personal data from form submissions, and other critical site data. Additionally, it was discovered that unauthenticated users could retrieve form entries without proper authorization, exposing potentially confidential information. A Reflected XSS vulnerability was also identified, capable of executing malicious scripts directly when certain parameters were improperly handled. Furthermore, in specific configurations where the iThemes Sync plugin was installed, the SQL injection could be leveraged to achieve server-side code execution, giving attackers full control over the compromised WordPress server. This combination of vulnerabilities painted a stark picture of the potential for comprehensive site compromise.
CVE Details
Product: Formidable Form Builder plugin for WordPress
Published: October 16, 2024
Severity: High
Status: Analyzed
Affected Products
This critical vulnerability specifically affects all versions of the Formidable Form Builder plugin for WordPress released before 2.05.03. If your WordPress website uses this plugin and has not been updated to version 2.05.03 or a newer release, it remains exposed to these significant security risks. It’s vital for all administrators and developers using this plugin to verify their installed version promptly.
Current Status
The status of CVE-2017-20192 is “Analyzed.” This means that the vulnerability has been fully researched, understood, and documented. The technical details of how it can be exploited, along with its potential impact, are now public knowledge. This broad awareness means that potential attackers are likely aware of this weakness, making it even more urgent for website owners to apply the necessary patches to protect their installations.
Severity Level
With a CVSS (Common Vulnerability Scoring System) score of 8.3, this vulnerability is classified as ‘High’ severity. A High severity rating indicates that exploitation can lead to a significant impact on the confidentiality, integrity, or availability of your system. In this particular case, the ability for unauthenticated attackers to inject and execute arbitrary web scripts or potentially gain full database access, and even remote code execution in specific scenarios, means the risks include extensive data breaches, complete website takeover, and severe disruption of services. Such a rating demands immediate attention and remediation to prevent potentially catastrophic outcomes for your website and its users.
Possible Solutions
The most effective and immediate solution to protect your WordPress site from CVE-2017-20192 and the related vulnerabilities is to update your Formidable Form Builder plugin to version 2.05.03 or a more recent release. The developers, Strategy11, swiftly addressed these flaws upon notification, providing robust patches. The update process is straightforward and applies to both the free and premium (Pro) versions of the plugin. Before initiating any plugin updates, always create a full backup of your WordPress website. This safeguard ensures that you can restore your site in case of unexpected issues during the update process. Beyond this specific patch, maintaining a proactive security posture by regularly updating all WordPress core files, themes, and plugins is paramount. Consider implementing a web application firewall (WAF) for an additional layer of protection against known and emerging threats like XSS and SQL injection. Furthermore, educating your team on secure coding practices for any custom developments and performing regular security audits can help maintain a strong defense.
References
- https://klikki.fi/adv/formidable.html
- https://wordpress.org/plugins/formidable/#developers
- https://www.wordfence.com/threat-intel/vulnerabilities/id/900fcaab-2424-4ae8-af18-95659db0dbe3?source=cve
