CVE-2024-2242 in Contact Form 7 Plugin
Summary
by MITRE • 03/14/2024
The Contact Form 7 plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the ‘active-tab’ parameter in all versions up to, and including, 5.9 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.
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Analysis
by VulDB Data Team • 04/13/2026
The Contact Form 7 plugin represents one of the most widely used contact form solutions for WordPress installations, with over 50 million downloads across various versions. This particular vulnerability affects all versions up to and including 5.9, making it a critical concern for countless WordPress sites that rely on this plugin for user interaction and data collection. The vulnerability stems from inadequate input validation mechanisms within the plugin's handling of the 'active-tab' parameter, which is typically used to manage the user interface state of form elements. When users navigate to specific contact form pages, the plugin processes this parameter without proper sanitization, creating a pathway for malicious actors to inject harmful scripts into the application's response.
The technical flaw manifests through a classic reflected cross-site scripting vulnerability that operates at the application layer, specifically targeting the plugin's administrative interface and user-facing forms. When an attacker crafts a malicious URL containing a specially crafted payload within the 'active-tab' parameter, the plugin fails to properly escape or filter this input before rendering it in the HTML response. This allows attackers to inject arbitrary JavaScript code that executes in the context of other users' browsers when they visit the compromised page. The vulnerability is particularly dangerous because it requires no authentication, meaning any user can exploit it simply by convincing a victim to click a malicious link. The reflected nature of the vulnerability means that the malicious script is not stored on the server but is instead reflected back to the user through the application's response, making it difficult to detect through traditional security scanning methods.
The operational impact of this vulnerability extends beyond simple script injection, as it can enable attackers to perform a wide range of malicious activities against unsuspecting users. Attackers can leverage this vulnerability to steal session cookies, redirect users to malicious websites, modify page content, or even perform actions on behalf of authenticated users if they have sufficient privileges. The vulnerability creates a persistent threat vector that can be exploited across multiple WordPress installations simultaneously, particularly affecting sites with high user traffic or those that rely heavily on form submissions. Given that Contact Form 7 is installed on millions of WordPress sites, the potential attack surface is enormous, with attackers able to target various user groups including administrators, editors, and regular site visitors. The vulnerability also aligns with common attack patterns described in the attack tree framework, where initial access through social engineering or link manipulation can escalate into more sophisticated attacks.
Security professionals should consider this vulnerability in the context of broader web application security principles and the specific threat landscape for content management systems. The vulnerability demonstrates a failure in input validation and output escaping practices that are fundamental to preventing XSS attacks, aligning with CWE-79 which specifically addresses cross-site scripting vulnerabilities. Organizations should implement immediate mitigations including updating to the latest plugin version, implementing proper input sanitization measures, and deploying web application firewalls that can detect and block malicious payloads. The ATT&CK framework's T1566 technique for "Phishing" becomes particularly relevant as attackers can exploit this vulnerability to deliver malicious scripts through compromised links, while T1071.001 for "Application Layer Protocol: Web Protocols" highlights the importance of monitoring HTTP request parameters for malicious content. Additionally, implementing Content Security Policy headers and regular security audits can provide additional defense layers to protect against similar vulnerabilities in the future.