CVE-2021-24967 in Contact Form & Lead Form Elementor Builder Plugin
Summary
by MITRE • 12/27/2021
The Contact Form & Lead Form Elementor Builder WordPress plugin before 1.6.4 does not sanitise and escape some lead values, which could allow unauthenticated users to perform Cross-Site Scripting attacks against logged in admin viewing the inserted Leads
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Analysis
by VulDB Data Team • 12/31/2021
The vulnerability identified as CVE-2021-24967 affects the Contact Form & Lead Form Elementor Builder WordPress plugin, specifically versions prior to 1.6.4. This issue represents a classic cross-site scripting vulnerability that arises from insufficient input sanitization and output escaping mechanisms within the plugin's lead management functionality. The flaw exists in how the plugin processes and displays lead data submitted through contact forms, creating an avenue for malicious actors to inject harmful scripts into the system.
The technical root cause of this vulnerability stems from the plugin's failure to properly sanitize user input before storing and rendering lead information. When unauthenticated users submit forms through the plugin's interface, the system does not adequately validate or escape the data before it is stored in the database or displayed in admin interfaces. This creates a persistent cross-site scripting vector where malicious payloads can be injected into form submissions and subsequently executed when administrators view these leads. The vulnerability specifically impacts the lead viewing functionality within the Elementor builder environment, where administrators access submitted form data through the WordPress admin dashboard.
From an operational perspective, this vulnerability poses significant risks to WordPress installations using the affected plugin. Attackers can exploit this weakness by crafting malicious form submissions containing javascript payloads or other malicious scripts that will execute in the context of an administrator's browser session. When logged-in administrators view the leads in the Elementor admin interface, these scripts execute automatically, potentially leading to session hijacking, privilege escalation, or data exfiltration. The vulnerability is particularly dangerous because it requires no authentication to exploit, making it accessible to anyone who can submit forms through the plugin's interface.
The impact of this vulnerability aligns with CWE-79, which describes cross-site scripting flaws that allow attackers to inject malicious scripts into web applications. This weakness falls under the broader category of injection vulnerabilities that compromise web application security. The ATT&CK framework would classify this as a code injection technique, specifically targeting the web application layer where user inputs are not properly validated. The vulnerability demonstrates a critical failure in the principle of least privilege and input validation, where the system trusts user-provided data without sufficient sanitization before rendering it in a privileged context.
Mitigation strategies for CVE-2021-24967 focus primarily on updating the plugin to version 1.6.4 or later, which contains the necessary sanitization and escaping fixes. Administrators should also implement additional security measures including input validation at multiple layers, output escaping for all dynamic content, and regular security audits of installed plugins. Network-level protections such as web application firewalls can provide additional defense-in-depth, though the primary solution remains the plugin update. Security monitoring should include detection of suspicious form submissions and unusual admin activity that might indicate exploitation attempts. The vulnerability underscores the importance of maintaining up-to-date WordPress plugins and implementing comprehensive security practices to prevent similar issues in other components of the web application stack.