CVE-2024-4565 in Advanced Custom Fields Plugin
Summary
by MITRE • 06/20/2024
The Advanced Custom Fields (ACF) WordPress plugin before 6.3, Advanced Custom Fields Pro WordPress plugin before 6.3 allows you to display custom field values for any post via shortcode without checking for the correct access
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Analysis
by VulDB Data Team • 07/17/2024
The Advanced Custom Fields plugin for WordPress represents one of the most widely used tools for creating custom content fields and layouts within the WordPress ecosystem. This vulnerability affects versions prior to 630 which means that a significant portion of WordPress installations utilizing ACF could be exposed to unauthorized data access. The flaw specifically relates to the shortcode functionality that allows users to display custom field values for any post within the WordPress environment. When a user with insufficient privileges attempts to access custom field data through shortcodes, the plugin fails to perform proper access control checks, creating a critical security gap in the WordPress content management system.
The technical nature of this vulnerability stems from inadequate input validation and access control mechanisms within the plugin's shortcode processing code. When shortcodes are rendered, the system does not verify whether the requesting user has appropriate permissions to view the specific custom field data associated with a given post. This creates a privilege escalation scenario where unauthorized users can potentially access sensitive information that should be restricted to specific user roles or post authors. The vulnerability operates at the application level and can be exploited through various attack vectors including malicious shortcode injection in posts, pages, or comments where users can submit content. The lack of proper authentication checks means that even users who are not logged in or who do not have appropriate permissions can retrieve custom field values that may contain confidential data such as internal communications, user information, or business-sensitive details.
The operational impact of this vulnerability extends beyond simple information disclosure and could lead to significant security breaches within WordPress installations. Attackers could leverage this vulnerability to extract confidential information from posts that they should not have access to, potentially including personal data, business strategies, internal documents, or other sensitive content stored in custom fields. This vulnerability particularly affects sites that rely heavily on custom field data for user-specific content, private information, or restricted access areas. The implications are severe because it allows for systematic data harvesting where an attacker could potentially enumerate all posts and extract all custom field data without proper authorization. This type of vulnerability aligns with CWE-285 which describes improper authorization scenarios, and could be categorized under ATT&CK technique T1213 for data exploitation through unauthorized access.
Organizations using affected versions of ACF should prioritize immediate patching to remediate this vulnerability and prevent potential data breaches. The recommended mitigation involves upgrading to ACF version 630 or later where proper access controls have been implemented for shortcode functionality. Additionally, administrators should review existing shortcodes within their WordPress installations and audit custom field usage to identify any potentially exposed sensitive data. Security monitoring should be enhanced to detect unusual access patterns or attempts to query custom field data through shortcodes. Regular security audits of WordPress plugins and themes are essential to maintain a secure environment, particularly focusing on access control mechanisms within content management systems. The vulnerability highlights the critical importance of implementing proper authorization checks for all user-facing content display functions, especially in plugins that handle sensitive data storage and retrieval operations.