CVE-2025-4431 Overview
The Featured Image Plus – Quick & Bulk Edit with Unsplash plugin for WordPress contains a missing authorization vulnerability. The flaw resides in the fip_save_attach_featured function and affects all versions up to and including 1.6.4. The function lacks a capability check, allowing authenticated users with Subscriber-level access or higher to modify the featured image of any post on the site. This weakness is tracked under CWE-284 (Improper Access Control) and CWE-862 (Missing Authorization).
Critical Impact
Authenticated attackers with minimal Subscriber privileges can alter the featured image of any published post, enabling content tampering and reputational harm.
Affected Products
- Krasenslavov Featured Image Plus – Quick & Bulk Edit with Unsplash for WordPress
- All versions up to and including 1.6.4
- WordPress installations with the plugin active and open user registration
Discovery Timeline
- 2025-05-30 - CVE-2025-4431 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-4431
Vulnerability Analysis
The vulnerability exists in the plugin's block editor action handler located in inc/admin/block-editor/block-editor-actions.php. The fip_save_attach_featured function processes requests to attach a featured image to a post but does not verify that the requesting user has permission to edit the target post. WordPress expects developers to invoke current_user_can('edit_post', $post_id) before performing state-changing operations. This check is absent, so any authenticated session can invoke the endpoint.
The plugin author addressed the issue in Changeset #3300380 and a follow-up in Changeset #3303087. The Wordfence Vulnerability Report documents the technical scope.
Root Cause
The root cause is a missing capability check on a privileged action handler. The plugin registers the AJAX endpoint but bypasses the standard WordPress authorization pattern. As a result, authorization is effectively delegated to authentication alone, which conflates "logged in" with "authorized to modify content."
Attack Vector
An attacker registers or uses an existing Subscriber account on the target WordPress site. The attacker then issues an HTTP request to the plugin's featured-image action, supplying a target post_id and an attachment identifier. Because no capability check gates the operation, the server updates the featured image metadata. The attack requires network access and low privileges, with no user interaction. See the WordPress Plugin Code Review for the affected code path.
Detection Methods for CVE-2025-4431
Indicators of Compromise
- Unexpected changes to _thumbnail_id post meta values on published posts or pages
- POST requests to the plugin's fip_save_attach_featured action originating from Subscriber-level user sessions
- New or recently registered low-privilege accounts issuing administrative-style AJAX requests
Detection Strategies
- Audit the WordPress postmeta table for _thumbnail_id changes correlated with non-editor user activity
- Review web server access logs for admin-ajax.php requests referencing the fip_save_attach_featured action
- Flag Subscriber accounts that generate AJAX calls to plugin endpoints outside expected user flows
Monitoring Recommendations
- Enable WordPress activity logging to record post metadata modifications and the acting user ID
- Monitor plugin version inventory to identify installations of Featured Image Plus at or below 1.6.4
- Alert on bulk featured-image changes across multiple posts within short time windows
How to Mitigate CVE-2025-4431
Immediate Actions Required
- Update the Featured Image Plus plugin to a version above 1.6.4 that includes the changesets 3300380 and 3303087
- Review Subscriber and Contributor accounts for unauthorized registrations and remove suspicious users
- Restore any tampered featured images from known-good backups
Patch Information
The vendor released fixes through WordPress Changeset #3300380 and WordPress Changeset #3303087, which introduce the missing capability checks on the fip_save_attach_featured handler. Administrators should upgrade through the WordPress plugin manager to receive both patches.
Workarounds
- Disable the Featured Image Plus plugin until a patched version is installed
- Disable open user registration by unchecking "Anyone can register" in WordPress General Settings
- Restrict access to admin-ajax.php for low-privilege sessions using a web application firewall rule
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.