CVE-2024-4261 in Responsive Contact Form Builder & Lead Generation Plugin
Summary
by MITRE • 05/22/2024
The Responsive Contact Form Builder & Lead Generation Plugin plugin for WordPress is vulnerable to arbitrary shortcode execution in all versions up to, and including, 1.9.1. This is due to the software allowing users to execute an action that does not properly validate a value before running do_shortcode. This makes it possible for authenticated attackers, with subscriber-level access and above, to execute arbitrary shortcodes.
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Analysis
by VulDB Data Team • 05/22/2024
The vulnerable WordPress plugin Responsive Contact Form Builder & Lead Generation represents a critical security weakness that exploits improper input validation mechanisms within the plugin's shortcode execution process. This vulnerability exists in all versions up to and including 1.9.1, creating a persistent risk for WordPress installations that utilize this particular plugin. The flaw stems from the plugin's failure to adequately validate user-supplied input before processing shortcode execution, allowing malicious actors to manipulate the system through legitimate plugin interfaces.
The technical implementation of this vulnerability occurs when authenticated users with subscriber-level privileges or higher can leverage the plugin's functionality to execute arbitrary shortcodes through crafted input parameters. This represents a privilege escalation issue where the standard access controls are bypassed through the plugin's insufficient sanitization of user-provided data. The vulnerability directly relates to CWE-79 which describes improper neutralization of input during web page generation, specifically manifesting as cross-site scripting vulnerabilities through shortcode manipulation.
The operational impact of this vulnerability extends beyond simple code execution as it enables attackers to leverage the plugin's legitimate features for malicious purposes. An authenticated attacker can construct specific shortcode parameters that, when processed by the do_shortcode function, execute arbitrary code within the WordPress environment. This creates opportunities for data exfiltration, malicious payload delivery, and potential compromise of the entire WordPress installation. The vulnerability affects not just the plugin's immediate functionality but can serve as a foothold for broader system exploitation.
Security professionals should recognize this vulnerability as a prime example of how plugin developers must implement proper input validation and sanitization before processing user-supplied data. The ATT&CK framework categorizes this issue under privilege escalation and code execution techniques where attackers leverage legitimate system functionality to bypass security controls. Organizations should immediately update to patched versions of the plugin or implement temporary mitigations such as role-based access restrictions and monitoring for unusual shortcode execution patterns.
The vulnerability demonstrates the importance of proper validation of user input in web applications and highlights how seemingly benign plugin features can become attack vectors when input sanitization is inadequate. This weakness also underscores the need for comprehensive security testing of WordPress plugins, particularly those that handle user-generated content or execute dynamic code. The attack surface expands significantly when plugins fail to validate data before processing, as demonstrated by the ability to execute arbitrary shortcodes through authenticated user access.
Mitigation strategies should include immediate patching of the vulnerable plugin to version 1.9.2 or later, which addresses the input validation weakness. Network monitoring should be enhanced to detect unusual shortcode execution patterns that may indicate exploitation attempts. Role-based access controls should be reviewed to minimize the privileges available to untrusted users, and comprehensive logging of shortcode processing activities should be implemented. Additionally, security teams should conduct vulnerability assessments of other plugins to identify similar input validation weaknesses that could be exploited in similar ways.