CVE-2024-1564: Schema Pro Auth Bypass Vulnerability

CVE-2024-1564 Overview

CVE-2024-1564 is a Broken Access Control vulnerability affecting the WP Schema Pro WordPress plugin developed by Brainstorm Force. The vulnerability exists in versions prior to 2.7.16 and allows authenticated users with contributor-level privileges to access custom fields on any post regardless of post type or status through a shortcode. This represents a significant authorization bypass that could lead to unauthorized information disclosure across a WordPress site.

Critical Impact

Contributor-level users can access sensitive custom field data from any post on the WordPress site, including private posts and restricted content types, potentially exposing confidential information.

Affected Products

• Brainstorm Force WP Schema Pro plugin versions prior to 2.7.16
• WordPress sites using vulnerable WP Schema Pro installations
• Any WordPress deployment with contributor-level user accounts and WP Schema Pro active

Discovery Timeline

• 2024-03-25 - CVE-2024-1564 published to NVD
• 2025-06-27 - Last updated in NVD database

Technical Details for CVE-2024-1564

Vulnerability Analysis

This Broken Access Control vulnerability stems from insufficient validation of post access permissions within the WP Schema Pro plugin's shortcode handling functionality. The plugin fails to properly verify whether the requesting user has legitimate access to the target post before returning custom field data through shortcode processing.

In WordPress, contributor-level users typically have limited permissions—they can create and edit their own posts but cannot publish them or access others' content. However, this vulnerability allows such users to craft shortcodes that retrieve custom field metadata from any post in the system, bypassing normal WordPress permission checks.

The exposure is particularly concerning because custom fields in WordPress often contain sensitive data such as internal notes, pricing information, user details, or configuration values that should remain private. Schema markup data itself may also contain business-sensitive information not intended for lower-privileged users.

Root Cause

The root cause of CVE-2024-1564 lies in the improper implementation of access control validation within the shortcode rendering logic. When the plugin processes a shortcode request to display schema-related custom fields, it retrieves the data directly without performing adequate checks to verify:

1. Whether the requesting user has permission to view the target post
2. Whether the target post's status (published, private, draft, etc.) permits access by the current user
3. Whether the post type's capabilities restrict access to certain user roles

This missing authorization check allows any authenticated user with at least contributor privileges to enumerate and extract custom field data across the entire WordPress installation.

Attack Vector

The attack leverages the network-accessible shortcode functionality with low complexity requirements. An attacker needs only valid contributor-level credentials to exploit this vulnerability. The attack flow involves:

1. Authenticating to WordPress with contributor-level or higher privileges
2. Creating or editing a post where the attacker has edit capabilities
3. Inserting a specially crafted shortcode that references another post's ID
4. Previewing or viewing the post to trigger the shortcode rendering
5. Observing the extracted custom field data from the unauthorized post

The vulnerability requires no user interaction from victims and can be exploited silently to harvest data from multiple posts systematically. While the scope is limited to confidentiality impact with no direct integrity or availability compromise, the information disclosure could facilitate further attacks or expose sensitive business data.

Detection Methods for CVE-2024-1564

Indicators of Compromise

• Unusual shortcode usage patterns in posts created by contributor-level users
• Posts containing shortcodes that reference post IDs outside the author's normal access
• Log entries showing repeated requests for post metadata from low-privilege accounts
• Evidence of post ID enumeration attempts in user-generated content

Detection Strategies

• Monitor WordPress audit logs for contributor users accessing custom field data from posts they do not own
• Implement content scanning to detect shortcodes referencing arbitrary post IDs in contributor drafts
• Review user activity patterns for systematic post ID enumeration behavior
• Deploy web application firewall rules to flag suspicious shortcode parameter patterns

Monitoring Recommendations

• Enable comprehensive WordPress activity logging for all user roles
• Configure alerts for unusual data access patterns by lower-privileged users
• Regularly audit posts created by contributors for suspicious shortcode usage
• Monitor for bulk data extraction attempts that could indicate automated exploitation

How to Mitigate CVE-2024-1564

Immediate Actions Required

• Update WP Schema Pro plugin to version 2.7.16 or later immediately
• Audit existing posts created by contributor-level users for potential exploitation attempts
• Review custom field data that may have been exposed to unauthorized users
• Consider temporarily restricting contributor access until the plugin is updated

Patch Information

Brainstorm Force addressed this vulnerability in WP Schema Pro version 2.7.16. The patch implements proper post access validation within the shortcode handling functionality to ensure users can only access custom field data from posts they are authorized to view. Update through the WordPress admin dashboard or download the latest version directly from the official source.

For detailed vulnerability information, refer to the WPScan Vulnerability Report.

Workarounds

• Temporarily disable the WP Schema Pro plugin if immediate updates are not possible
• Remove contributor-level access from untrusted users until the patch is applied
• Implement role-based restrictions to limit shortcode usage to trusted roles only
• Deploy a web application firewall rule to block suspicious shortcode parameters

# WordPress CLI command to update the plugin
wp plugin update wp-schema-pro --version=2.7.16

# Verify current plugin version
wp plugin get wp-schema-pro --field=version

# Temporarily deactivate the plugin if update is not immediately possible
wp plugin deactivate wp-schema-pro