Stored XSS in Avada Builder WordPress Plugin

Executive Summary

This vulnerability is a Stored Cross-Site Scripting (XSS) issue in the Avada (Fusion) Builder plugin for WordPress. It affects all versions up to and including 3.15.5.

The vulnerability occurs due to insufficient input sanitization and output escaping of the ‘Module Title’ parameter. This allows authenticated attackers with Contributor-level access or higher to inject arbitrary web scripts into pages. These scripts will execute whenever a user accesses an affected page.

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Detection Guidance

Detecting this vulnerability involves checking for signs of stored cross-site scripting (XSS) in WordPress pages or posts created or edited using the Avada (Fusion) Builder plugin. Since the vulnerability is related to the 'Module Title' parameter, you should look for malicious scripts injected into this field.

• Review WordPress pages or posts edited with the Avada Builder plugin for suspicious JavaScript or HTML in the 'Module Title' fields. This can be done manually by inspecting the content in the WordPress editor or database.
• Use a WordPress security plugin like Wordfence to scan for known vulnerabilities or malicious scripts in your WordPress installation. Wordfence can detect and report stored XSS vulnerabilities.
• Check the WordPress database for entries in the 'postmeta' table where the 'meta_key' is related to Avada Builder modules. Look for unusual or obfuscated JavaScript in the 'meta_value' field.
• Monitor web traffic or logs for unexpected script executions originating from pages created with the Avada Builder plugin. Tools like ModSecurity or a web application firewall (WAF) can help identify suspicious activity.

Example command to search the WordPress database for suspicious entries (replace 'wp_' with your database prefix if different):

• SELECT * FROM wp_postmeta WHERE meta_key LIKE '%fusion%' AND meta_value LIKE '%<script%' OR meta_value LIKE '%onerror%' OR meta_value LIKE '%javascript%';

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Impact Analysis

If you are using the Avada (Fusion) Builder plugin for WordPress, this vulnerability could have several impacts:

• Attackers with Contributor-level access or higher could inject malicious scripts into your website pages.
• These scripts could execute in the browsers of users who visit the infected pages, potentially leading to unauthorized actions such as stealing session cookies, redirecting users to malicious sites, or performing actions on behalf of the user.
• The vulnerability could compromise the integrity and confidentiality of your website and its users.

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Compliance Impact

This vulnerability could impact compliance with several common standards and regulations in the following ways:

• GDPR (General Data Protection Regulation): If the injected scripts lead to unauthorized access or disclosure of personal data of EU citizens, it could result in a violation of GDPR. Organizations may face significant fines and be required to notify affected individuals.
• HIPAA (Health Insurance Portability and Accountability Act): For organizations handling protected health information (PHI), if the vulnerability leads to unauthorized access or exposure of PHI, it could constitute a HIPAA violation. This may result in penalties and mandatory corrective actions.
• Other standards like PCI DSS (Payment Card Industry Data Security Standard): If the website processes payment card information, the vulnerability could lead to non-compliance with PCI DSS requirements for protecting cardholder data, potentially resulting in fines or restrictions on payment processing.

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Mitigation Strategies

To mitigate this vulnerability, follow these immediate steps:

• Update the Avada (Fusion) Builder plugin to the latest version if a patch is available. The vulnerability affects versions up to and including 3.15.5, so updating to a fixed version is critical.
• If an update is not yet available, restrict access to the Avada Builder plugin for users with Contributor-level access or higher. This can be done by adjusting user roles and permissions in WordPress.
• Use a web application firewall (WAF) to block malicious script injections. A WAF can help filter out XSS attempts before they reach your WordPress site.
• Manually review and clean any suspicious content in the 'Module Title' fields of pages or posts created with the Avada Builder plugin. Remove any unexpected scripts or HTML.
• Monitor your WordPress site for unusual activity, such as unexpected script executions or unauthorized changes to content. Enable logging and alerts for suspicious behavior.
• Consider temporarily disabling the Avada Builder plugin if the risk is deemed too high and no patch is available. Replace it with an alternative plugin until a fix is released.

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