CVE-2025-35032

Executive Summary

CVE-2025-35032 is a medium-severity vulnerability in Medical Informatics Engineering (MIE) Enterprise Health, a healthcare data management platform. The flaw allows authenticated users to upload arbitrary files to the server. The impact depends on how the uploaded files are subsequently accessed or executed. If the application serves uploaded files from a web-accessible directory without proper validation, an attacker could upload a malicious script (e.g., PHP, JSP, ASPX) and achieve remote code execution. If files are stored in a non-executable directory, the impact is limited to unauthorized data storage or potential phishing via uploaded HTML files. The vendor released a fix on 2025-04-08, but no specific version or patch commit has been publicly disclosed.

Supply Chain & Package Security

This vulnerability is not related to an open-source package manager (NPM, PyPI, Go, Ruby). It affects a proprietary healthcare application. Supply chain risk is limited to the vendor's internal development and deployment processes.

CVSS Breakdown & Threat Level

• CVSS Score: 3.4 (Low)
• Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: Low (Authenticated user)
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: Low (potential file disclosure)
• Integrity Impact: None (unless file execution is possible)
• Availability Impact: None

Threat Level: Low. The vulnerability requires authentication and the impact is limited unless the application is misconfigured to execute uploaded files.

Deep Dive & Mechanics

The vulnerability resides in the file upload functionality of MIE Enterprise Health. The application fails to validate the type or content of uploaded files. An authenticated user can upload any file type, including executable scripts (e.g., .php, .jsp, .aspx, .py). If the application stores these files in a web-accessible directory and the web server is configured to execute them, an attacker can achieve remote code execution. If the files are stored in a non-executable directory, the attacker can still upload malicious HTML files for phishing or store arbitrary data.

The root cause is a lack of file type validation and insufficient access controls on the upload directory. The fix likely involves implementing a whitelist of allowed file types, storing uploads outside the web root, and/or disabling execution permissions on the upload directory.

Vulnerable vs. Patched Code

No specific code snippets are available. The vulnerable code likely resembles:

// Vulnerable: No validation
$target_dir = "uploads/";
$target_file = $target_dir . basename($_FILES["file"]["name"]);
move_uploaded_file($_FILES["file"]["tmp_name"], $target_file);

The patched code should include:

// Patched: Validate file type and store outside web root
$allowed_types = ['pdf', 'doc', 'docx', 'jpg', 'png'];
$file_ext = strtolower(pathinfo($_FILES["file"]["name"], PATHINFO_EXTENSION));
if (!in_array($file_ext, $allowed_types)) {
    die("File type not allowed.");
}
$target_dir = "/secure/storage/"; // Outside web root
$target_file = $target_dir . uniqid() . "." . $file_ext;
move_uploaded_file($_FILES["file"]["tmp_name"], $target_file);

Exploitation & Lab Setup

Red Team

1. Prerequisites: Authenticated session on MIE Enterprise Health.
2. Identify Upload Endpoint: Locate the file upload form (e.g., /upload.php, /api/upload).
3. Craft Payload: Create a malicious file (e.g., shell.php containing a web shell).
4. Upload: Use a tool like curl or Burp Suite to upload the file.
5. Access: Navigate to the uploaded file URL (e.g., https://target.com/uploads/shell.php).
6. Execute: If the server executes the file, you gain remote code execution.

Example curl command:

curl -X POST -F "file=@shell.php" -b "session=valid_session_cookie" https://target.com/upload.php

Blue Team

1. Monitor File Uploads: Enable logging for all file upload requests.
2. Web Application Firewall (WAF): Deploy rules to block uploads of executable file types (.php, .jsp, .asp, .exe, .sh).
3. File Integrity Monitoring (FIM): Monitor the upload directory for new files and alert on suspicious extensions.
4. Network Segmentation: Ensure the upload directory is not directly accessible from the web.
5. Static Analysis: Review the application code for file upload validation.

Indicators of Compromise (IOCs)

• File Hashes (SHA256): (Example - replace with actual if discovered)
  • e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855 (empty file)
• Network Indicators:
  • POST requests to /upload.php or similar endpoints with multipart/form-data.
  • Outbound connections from the server to unknown IPs (if web shell is used).
• File System Indicators:
  • Unexpected files in the upload directory with extensions .php, .jsp, .asp, .aspx, .sh, .py.
  • Files with names like shell.php, cmd.php, backdoor.jsp.

Detection Engineering

YARA Rule

rule CVE_2025_35032_Uploaded_Webshell {
    meta:
        description = "Detects potential web shells uploaded via CVE-2025-35032"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-35032"
    strings:
        $php_shell = /<\?php\s*(system|exec|shell_exec|passthru|eval|assert)\s*\(/
        $jsp_shell = /Runtime\.getRuntime\(\)\.exec\(/
        $asp_shell = /CreateObject\("WScript\.Shell"\)/
    condition:
        any of them
}

Sigma Rule

title: CVE-2025-35032 - Suspicious File Upload to MIE Enterprise Health
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects upload of executable files to MIE Enterprise Health
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/upload.php'
        cs-uri-query|contains: '.php'
    condition: selection
falsepositives:
    - Legitimate PHP file uploads (if allowed by application)
level: medium

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2025-35032 - MIE Enterprise Health File Upload Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/upload.php"; http_uri; content:".php"; http_client_body; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

1. Apply Vendor Patch: Update MIE Enterprise Health to the latest version released after 2025-04-08.
2. File Upload Validation: Implement strict file type whitelisting (e.g., only allow images, PDFs, documents).
3. Store Uploads Outside Web Root: Move uploaded files to a directory not accessible via the web server.
4. Disable Execution: Ensure the upload directory has no execute permissions (e.g., chmod -R 644 on Linux).
5. Web Application Firewall (WAF): Deploy rules to block uploads of executable file types.
6. Regular Audits: Review file upload logs and monitor for suspicious activity.

Valters IT
Securing Healthcare, One CVE at a Time.