CVE-2023-0710 in Metform Elementor Contact Form Builder Plugin
Summary
by MITRE • 06/09/2023
The Metform Elementor Contact Form Builder for WordPress is vulnerable to Cross-Site Scripting by using the 'fname' attribute of the 'mf_thankyou' shortcode to echo unescaped form submissions in versions up to, and including, 3.3.0. This allows authenticated attackers, with contributor-level permissions or above, to inject arbitrary web scripts in pages that will execute when the victim visits a a page containing the shortcode when the submission id is present in the query string. Note that getting the JavaScript to execute requires user interaction as the victim must visit a crafted link with the form entry id, but the script itself is stored in the site database. Additionally this requires successful payment, increasing the complexity.
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Analysis
by VulDB Data Team • 07/07/2023
The vulnerability identified as CVE-2023-0710 affects the Metform Elementor Contact Form Builder plugin for WordPress, specifically impacting versions up to and including 3.3.0. This represents a cross-site scripting vulnerability that stems from improper input sanitization within the plugin's handling of form submissions. The flaw is particularly concerning as it allows authenticated attackers with contributor-level permissions or higher to inject malicious scripts into the WordPress environment. The vulnerability manifests through the 'fname' attribute of the 'mf_thankyou' shortcode, which fails to properly escape user-provided input before rendering it in web pages. This oversight creates a persistent XSS vector where malicious code can be stored in the site's database and subsequently executed whenever victims visit pages containing the affected shortcode with specific query parameters.
The technical execution of this vulnerability requires several conditions to be met, making it somewhat complex but still exploitable within the right circumstances. Attackers must first obtain contributor-level permissions or higher within the WordPress environment, which represents a significant access requirement. The attack vector involves crafting malicious input through form submissions that are then stored in the database, with the actual execution requiring user interaction through visiting a crafted link containing the form entry id in the query string. This approach follows the typical pattern of stored XSS vulnerabilities where the malicious payload is stored server-side rather than being reflected in HTTP responses. The requirement for successful payment processing adds another layer of complexity to the exploitation, potentially limiting the attack surface to scenarios where payment forms are involved.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform various malicious activities including session hijacking, data theft, and redirection to malicious sites. The stored nature of the payload means that the malicious code persists even after the initial injection, allowing for sustained attacks against unsuspecting users who visit affected pages. The vulnerability's classification aligns with CWE-79, which describes improper neutralization of input during web page generation, specifically addressing cross-site scripting flaws. From an ATT&CK perspective, this vulnerability maps to techniques involving code injection and privilege escalation, as attackers must first establish sufficient permissions before executing the XSS payload. The requirement for payment processing to successfully exploit the vulnerability suggests that this may be particularly relevant in e-commerce contexts where payment forms are common, potentially making it more attractive to attackers targeting online businesses.
Mitigation strategies for CVE-2023-0710 should focus on immediate plugin updates to versions that address the XSS vulnerability, as well as implementing proper input validation and output escaping mechanisms. Administrators should also consider implementing additional security measures such as web application firewalls, regular security audits of form submissions, and monitoring for unusual patterns in form data. The vulnerability highlights the importance of proper sanitization of user inputs in web applications, particularly in plugins that handle form data and user-generated content. Organizations should also implement principle of least privilege, ensuring that users with contributor-level permissions or higher are carefully monitored and that unnecessary permissions are not granted. Regular vulnerability assessments and penetration testing can help identify similar issues in other plugins and themes that may be susceptible to cross-site scripting attacks. The incident underscores the critical need for maintaining up-to-date security practices and the importance of thorough code review processes for all plugin and theme development to prevent such vulnerabilities from being introduced into production environments.