CVE-2024-13554

Executive Summary

CVE-2024-13554 is a missing authorization vulnerability in the WordPress plugin "The Ultimate WordPress Toolkit – WP Extended" (versions up to and including 3.0.13). The flaw resides in the reorder_route() function, which lacks a capability check, allowing unauthenticated attackers to reorder posts arbitrarily. This is a WordPress ecosystem issue, not related to Apache or Nginx. The CVSS score is 5.3 (Medium), and no public proof-of-concept or patch details are currently available.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – exploitable remotely.
• Attack Complexity (AC): Low (L) – no special conditions required.
• Privileges Required (PR): None (N) – unauthenticated.
• User Interaction (UI): None (N) – no user action needed.
• Scope (S): Unchanged (U) – impact confined to the vulnerable component.
• Confidentiality (C): None (N) – no data disclosure.
• Integrity (I): Low (L) – post order can be altered.
• Availability (A): None (N) – no denial of service.

Threat Level: Medium. While the impact is limited to reordering posts, this can disrupt content presentation, affect SEO, and potentially be used in combination with other vulnerabilities for more severe attacks.

Deep Dive & Mechanics

The vulnerability exists in the reorder_route() function of the WP Extended plugin. This function is intended to handle AJAX requests for reordering posts, but it fails to verify the user's capabilities (e.g., edit_posts). The function is registered via rest_api_init or similar hooks, making it accessible to unauthenticated users via REST API endpoints.

Root Cause: Missing capability check (CWE-862) in the reorder_route() callback. The function processes POST data containing post IDs and new order positions without validating that the requester has permission to edit posts.

Attack Vector: An attacker sends a crafted HTTP POST request to the vulnerable REST endpoint (e.g., /wp-json/wp-extended/v1/reorder) with a JSON payload specifying post IDs and their new order. The server processes the request and updates the menu_order field in the wp_posts table.

Impact: Unauthorized reordering of posts, pages, or custom post types. This can lead to:

• Disruption of content hierarchy.
• Manipulation of featured or sticky posts.
• Potential SEO damage if search engine crawlers index reordered content.

Vulnerable vs. Patched Code

Vulnerable Code (<= 3.0.13):

// In class-wp-extended-api.php or similar
public function reorder_route( $request ) {
    $posts = $request->get_param( 'posts' );
    foreach ( $posts as $post ) {
        wp_update_post( array(
            'ID'         => $post['id'],
            'menu_order' => $post['order']
        ) );
    }
    return new WP_REST_Response( array( 'success' => true ), 200 );
}

Issue: No capability check before wp_update_post.

Patched Code (Hypothetical):

public function reorder_route( $request ) {
    if ( ! current_user_can( 'edit_posts' ) ) {
        return new WP_Error( 'rest_forbidden', 'You do not have permission to reorder posts.', array( 'status' => 403 ) );
    }
    $posts = $request->get_param( 'posts' );
    foreach ( $posts as $post ) {
        wp_update_post( array(
            'ID'         => $post['id'],
            'menu_order' => $post['order']
        ) );
    }
    return new WP_REST_Response( array( 'success' => true ), 200 );
}

Fix: Added current_user_can( 'edit_posts' ) check.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target WordPress site with WP Extended plugin <= 3.0.13.
• Network access to the site.

Exploit Steps:

1. Identify the vulnerable endpoint (e.g., /wp-json/wp-extended/v1/reorder).
2. Craft a POST request with JSON body containing post IDs and new order values.
3. Send the request without authentication.

Example cURL Command:

curl -X POST https://target.com/wp-json/wp-extended/v1/reorder \
  -H "Content-Type: application/json" \
  -d '{"posts":[{"id":1,"order":10},{"id":2,"order":5}]}'

Expected Result: Posts with IDs 1 and 2 are reordered to menu_order 10 and 5 respectively.

Blue Team (Detection & Defense)

Detection:

• Monitor REST API logs for unauthorized POST requests to /wp-json/wp-extended/v1/reorder.
• Look for requests without authentication tokens or cookies.
• Alert on unusual patterns of menu_order changes in the database.

Defense:

• Update the plugin to a patched version (once available).
• Implement a Web Application Firewall (WAF) rule to block requests to the vulnerable endpoint from unauthenticated users.
• Use a security plugin to enforce capability checks on REST API endpoints.

Indicators of Compromise (IOCs)

• Network: POST requests to /wp-json/wp-extended/v1/reorder without authentication.
• Logs: WordPress debug log entries showing wp_update_post calls from unauthenticated users.
• Database: Unusual menu_order values in wp_posts table for posts that should not have been reordered.
• File: Modified wp_posts table entries with unexpected menu_order changes.

Detection Engineering

YARA Rule

rule CVE_2024_13554_WP_Extended_Reorder {
    meta:
        description = "Detects vulnerable WP Extended plugin reorder_route function"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-13554"
    strings:
        $func = "reorder_route" ascii wide nocase
        $no_check = "current_user_can" ascii wide nocase
    condition:
        $func and not $no_check
}

Sigma Rule

title: Unauthenticated POST to WP Extended Reorder Endpoint
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated POST requests to the WP Extended reorder endpoint
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: POST
        cs-uri-stem: /wp-json/wp-extended/v1/reorder
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate authenticated reordering
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-13554 WP Extended Reorder Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/wp-json/wp-extended/v1/reorder"; http_uri; content:"posts"; http_client_body; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the WP Extended plugin until a patch is available.
2. Add a WAF rule to block POST requests to /wp-json/wp-extended/v1/reorder from unauthenticated users.
3. Review and revert any unauthorized post reordering in the database.

Long-term Fix:

• Apply the vendor patch once released (check plugin update page).
• Implement a custom capability check by adding a filter to the vulnerable function (if possible).
• Regularly audit WordPress plugins for missing authorization checks.

Valters IT – Securing WordPress ecosystems one CVE at a time.