CVE-2025-61506: MediaCrush File Upload RCE Vulnerability

CVE-2025-61506 Overview

CVE-2025-61506 is an unrestricted file upload vulnerability discovered in MediaCrush through version 1.0.1. The vulnerability allows remote unauthenticated attackers to upload arbitrary files of any size to the /upload endpoint without proper validation or restrictions.

Critical Impact

Unauthenticated attackers can upload files of any type and size, potentially leading to remote code execution, server compromise, or denial of service through storage exhaustion.

Affected Products

• MediaCrush versions up to and including 1.0.1

Discovery Timeline

• 2026-02-03 - CVE CVE-2025-61506 published to NVD
• 2026-02-04 - Last updated in NVD database

Technical Details for CVE-2025-61506

Vulnerability Analysis

This vulnerability is classified as CWE-434 (Unrestricted Upload of File with Dangerous Type). The MediaCrush application fails to implement proper validation controls on its /upload endpoint, allowing unauthenticated users to upload files without restrictions on file type, content, or size.

The lack of authentication on this endpoint means any remote attacker can exploit this vulnerability without requiring credentials. Combined with the absence of file type validation, attackers can upload malicious executable files, web shells, or other dangerous content directly to the server.

Root Cause

The root cause stems from insufficient input validation and missing access controls on the file upload functionality. The /upload endpoint accepts file submissions without verifying the user's authentication status and fails to enforce restrictions on the uploaded file's MIME type, extension, or size. This represents a fundamental security design flaw in the application's upload handling mechanism.

Attack Vector

The attack can be executed remotely over the network without any user interaction or authentication requirements. An attacker can craft malicious HTTP POST requests to the /upload endpoint containing dangerous file payloads. The attack process typically involves:

1. Identifying a vulnerable MediaCrush instance
2. Crafting a multipart/form-data POST request to the /upload endpoint
3. Uploading a malicious file (such as a web shell or executable)
4. Accessing the uploaded file to trigger execution or further exploitation

Technical details and a proof-of-concept are available in the GitHub Gist PoC published by the researcher.

Detection Methods for CVE-2025-61506

Indicators of Compromise

• Unusual file uploads to the MediaCrush /upload endpoint from external IP addresses
• Presence of unexpected file types in the MediaCrush upload directory (e.g., .php, .jsp, .aspx, .exe files)
• Large volume of POST requests to /upload from single sources
• Web shell signatures or executable files in media storage directories

Detection Strategies

• Monitor HTTP POST requests to /upload endpoints for suspicious file extensions and MIME types
• Implement file integrity monitoring on MediaCrush upload directories to detect unauthorized files
• Configure web application firewalls (WAF) to inspect and block requests containing dangerous file types
• Review web server access logs for patterns of unauthenticated upload attempts

Monitoring Recommendations

• Enable detailed logging for all file upload operations including source IP, file name, size, and type
• Set up alerts for uploads of executable file types or files exceeding normal size thresholds
• Monitor disk usage on servers hosting MediaCrush for unexpected storage consumption
• Implement network-level monitoring to detect outbound connections from uploaded files attempting command and control communication

How to Mitigate CVE-2025-61506

Immediate Actions Required

• Restrict access to the /upload endpoint using network-level controls or web server configuration
• Implement authentication requirements for all file upload functionality
• Deploy a web application firewall with rules to block dangerous file uploads
• Audit existing uploaded files for any malicious content that may have been previously uploaded

Patch Information

No official patch information is currently available from the vendor. Organizations using MediaCrush should implement the workarounds described below and monitor for official security updates. Additional technical details can be found in the GitHub Gist PoC.

Workarounds

• Disable the /upload endpoint entirely if file upload functionality is not required
• Implement server-side file type validation using allowlists for permitted MIME types and extensions
• Add file size limits to prevent storage exhaustion attacks
• Store uploaded files outside the web root and serve them through a separate handler that prevents execution
• Require authentication before allowing any file uploads

# Example nginx configuration to restrict upload endpoint access
location /upload {
    # Deny all external access to upload endpoint
    deny all;
    
    # Or restrict to specific trusted IP addresses
    # allow 192.168.1.0/24;
    # deny all;
}