Auto Featured Image - Reflected cross-site scripting (XSS)

Summary

Name	Auto Featured Image (Auto Post Thumbnail) 4.1. - Reflected cross-site scripting (XSS)
Code name	skims-0035
Product	Auto Featured Image (Auto Post Thumbnail)
Affected versions	Version 4.1.
State	Private
Release date	2025-03-14

Vulnerability

Kind	Reflected cross-site scripting (XSS)
Rule	Reflected cross-site scripting (XSS)
Remote	No
CVSSv4 Vector	CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:H/VI:L/VA:L/SC:L/SI:L/SA:L/E:U
CVSSv4 Base Score	4.8 (Medium)
Exploit available	No
CVE ID(s)	CVE-2025-31308

Description

Auto Featured Image (Auto Post Thumbnail) 4.1. was found to be vulnerable. The web application dynamically generates web content without validating the source of the potentially untrusted data in myapp/includes/class-apt.php.

Vulnerability

Skims by Fluid Attacks discovered a Reflected cross-site scripting (XSS) in Auto Featured Image (Auto Post Thumbnail) 4.1.. The following is the output of the tool:

Skims output

 726 | public function apt_get_thumbnail() {
 727 | if ( isset( $_POST['post_id'] ) && ! empty( $_POST['post_id'] ) ) {
 728 | $post_id = intval( $_POST['post_id'] );
 729 | if ( ! current_user_can( 'edit_post', $post_id ) ) {
 730 | wp_die( - 1 );
 731 | } else {
 732 | check_ajax_referer( 'set_post_thumbnail-' . $post_id );
 733 | $nonce = $_POST['_ajax_nonce'];
 734 | ?>
 735 | <div class='apt_thumbs' id='wapt_thumbs'>
 736 | <div class='wapt-grid-item'>
 737 | <div class=""wapt-image-box-library""
 738 | data-choose='<?php echo __( 'Choose featured image', 'apt' ); ?>'
 739 | data-update='<?php echo __( 'Select image', 'apt' ); ?>'
 740 | data-postid='<?php echo $post_id; ?>'
> 741 | data-nonce='<?php echo $nonce; ?>'
 742 | style=""background-color: #a3d2ff;"">
 743 | <div class=""wapt-item-generated""><?php echo __( 'Set featured image from medialibrary', 'apt'
 744 | </div>
 745 | </div>
 746 | </div>
  747 |     <?php
  748 |    }
  749 |   }
  750 |
  751 |   include WAPT_ABSPATH . '/admin/views/pro_column.php';
  752 |   die();
  753 |  }
      ^ Col 0

Our security policy

We have reserved the ID CVE-2025-31308 to refer to this issue from now on.

• https://fluidattacks.com/advisories/policy/

System Information

• Product: Auto Featured Image (Auto Post Thumbnail)
• Version: 4.1.

Mitigation

There is currently no patch available for this vulnerability.

Credits

The vulnerability was discovered by Andres Roldan from Fluid Attacks' Offensive Team using Skims

Timeline