CVE-2024-52004

Executive Summary

CVE-2024-52004 is a critical vulnerability in MediaCMS, an open-source video and media content management system built with Python/Django and React. The vulnerability stems from insufficient input validation during media file uploads, which can lead to remote code execution (RCE) under specific conditions. The primary attack vector requires the portal to allow user content uploads. All versions prior to v4.1.0 are affected. No known workarounds exist, and the vendor has released a patched version (4.1.0). The EPSS score is 0.0%, indicating low exploitation activity at the time of analysis, but the potential impact is severe.

Supply Chain & Package Security

MediaCMS is a Python/Django application. The vulnerability is in the core application code, not in a specific package dependency. However, the application relies on various Python packages for media processing (e.g., FFmpeg, Pillow). While the vulnerability is not a direct supply chain attack, the RCE could be used to compromise the host system and potentially pivot to other parts of the infrastructure. Users should ensure all dependencies are up-to-date and that the application runs with the least privileges necessary.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, which is likely a placeholder or unassigned. Based on the description (RCE via file upload), the likely CVSS v3.1 vector would be:

• Attack Vector (AV): Network (N) – The vulnerability is exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions are required beyond the ability to upload files.
• Privileges Required (PR): Low (L) – The attacker needs a user account with upload permissions.
• User Interaction (UI): None (N) – No user interaction is required.
• Scope (S): Unchanged (U) – The vulnerability affects the same security authority.
• Confidentiality (C): High (H) – RCE can lead to full data access.
• Integrity (I): High (H) – RCE can modify or delete data.
• Availability (A): High (H) – RCE can disrupt service.

Estimated CVSS Score: 8.8 (High)

Threat Level: High. The vulnerability allows for complete compromise of the MediaCMS instance and potentially the underlying server.

Deep Dive & Mechanics

The vulnerability is rooted in insufficient input validation during media file uploads. MediaCMS processes uploaded files (videos, images, audio) using various libraries. The lack of proper validation allows an attacker to upload a malicious file that, when processed or accessed, executes arbitrary code.

Attack Flow:

1. Authentication: The attacker must have a user account with upload permissions on the MediaCMS portal.
2. File Upload: The attacker uploads a specially crafted file (e.g., a video file with embedded malicious code, a PHP file disguised as an image, or a file that exploits a parser vulnerability).
3. Processing/Execution: When MediaCMS processes the file (e.g., generating thumbnails, transcoding, or serving the file), the malicious payload is executed.
4. RCE: The attacker gains remote code execution on the server, allowing them to execute system commands, access the database, or pivot to other systems.

Root Cause: The application does not properly validate the file type, content, or metadata. It may rely on file extensions or MIME types, which can be easily spoofed. Additionally, the processing pipeline (e.g., FFmpeg, ImageMagick) may have vulnerabilities that are triggered by malformed files.

Vulnerable vs. Patched Code

Since no specific code diff is available, the following is a hypothetical example of the vulnerable and patched code patterns.

Vulnerable Code (Python/Django):

# views.py
def upload_media(request):
    if request.method == 'POST':
        file = request.FILES['media_file']
        # No validation of file content or type
        media = Media.objects.create(
            file=file,
            user=request.user
        )
        # Process the file (e.g., generate thumbnail)
        process_media(media)
        return JsonResponse({'status': 'success'})

Patched Code (Python/Django):

# views.py
import magic
from django.core.exceptions import ValidationError

ALLOWED_MIME_TYPES = ['video/mp4', 'image/jpeg', 'audio/mpeg']

def upload_media(request):
    if request.method == 'POST':
        file = request.FILES['media_file']
        # Validate MIME type using python-magic
        mime_type = magic.from_buffer(file.read(1024), mime=True)
        if mime_type not in ALLOWED_MIME_TYPES:
            raise ValidationError('Invalid file type')
        # Validate file extension
        ext = file.name.split('.')[-1].lower()
        if ext not in ['mp4', 'jpg', 'mp3']:
            raise ValidationError('Invalid file extension')
        # Additional content validation (e.g., check for embedded scripts)
        media = Media.objects.create(
            file=file,
            user=request.user
        )
        # Process the file safely
        process_media_safe(media)
        return JsonResponse({'status': 'success'})

Exploitation & Lab Setup

Red Team

Objective: Achieve RCE on the MediaCMS server.

Prerequisites:

• A user account with upload permissions on the target MediaCMS instance.
• Network access to the target.

Steps:

1. Reconnaissance: Identify the MediaCMS version (e.g., via HTTP headers or /api/ endpoints).
2. Craft Payload: Create a malicious file. For example, a video file with embedded JavaScript (if the player is vulnerable) or a PHP file disguised as an image (if the server executes PHP).

   # craft_payload.py
   import os
   # Create a malicious JPEG file with PHP code
   payload = b'\xFF\xD8\xFF\xE0'  # JPEG header
   payload += b'<?php system($_GET["cmd"]); ?>'
   payload += b'\xFF\xD9'  # JPEG end
   with open('malicious.jpg', 'wb') as f:
       f.write(payload)
   

3. Upload: Log in to the MediaCMS portal and upload the malicious file.
4. Trigger: Access the uploaded file directly or via a processing endpoint. If the file is executed as PHP, access http://target/media/malicious.jpg?cmd=id.
5. Escalate: Use the initial foothold to escalate privileges or pivot.

Note: The exact exploitation method depends on the server configuration (e.g., whether PHP is installed, whether FFmpeg has known vulnerabilities).

Blue Team

Objective: Detect and prevent exploitation.

Steps:

1. Monitor File Uploads: Log all file uploads, including user, filename, size, and MIME type.
2. Validate Files: Implement strict validation on the server side (as shown in the patched code).
3. Sandbox Processing: Run media processing in a sandboxed environment (e.g., Docker container with limited privileges).
4. Web Application Firewall (WAF): Deploy WAF rules to block suspicious file uploads (e.g., files with double extensions, files containing PHP code).
5. Endpoint Detection and Response (EDR): Monitor for unusual process execution (e.g., FFmpeg spawning a shell).
6. Network Segmentation: Isolate the MediaCMS server from critical systems.

Indicators of Compromise (IOCs)

• File Hashes (SHA256): (Hypothetical – replace with actual hashes if available)
  • malicious.jpg: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855
• Network Indicators:
  • Outbound connections from the MediaCMS server to unknown IPs (e.g., for C2).
  • Unusual HTTP requests to /media/ or /api/ endpoints with cmd parameters.
• File System Indicators:
  • Unexpected files in the media upload directory (e.g., .php files).
  • Modified system files (e.g., /etc/passwd).
• Process Indicators:
  • ffmpeg or convert (ImageMagick) spawning a shell (/bin/sh, /bin/bash).
  • Unusual processes running as the web server user (e.g., www-data).

Detection Engineering

YARA Rule

rule CVE_2024_52004_MediaCMS_RCE {
    meta:
        description = "Detects malicious files targeting CVE-2024-52004 in MediaCMS"
        author = "Valters IT"
        date = "2024-01-01"
        reference = "CVE-2024-52004"
    strings:
        $php_code = "<?php" nocase
        $js_code = "<script" nocase
        $elf_magic = { 7f 45 4c 46 }  // ELF magic bytes
        $pe_magic = { 4d 5a }          // PE magic bytes
    condition:
        // File is a media type but contains executable code
        (uint16(0) == 0xFFD8 or uint16(0) == 0x8950 or uint16(0) == 0x0000) and
        ($php_code or $js_code or $elf_magic or $pe_magic)
}

Sigma Rule

title: MediaCMS File Upload RCE Attempt
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects attempts to exploit CVE-2024-52004 by uploading malicious files to MediaCMS
author: Valters IT
date: 2024/01/01
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/api/media/upload'
        sc-status: 200
    filter:
        cs-uri-query: '*.php*'
    condition: selection and filter
falsepositives:
    - Legitimate PHP files if the server uses PHP
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (msg:"CVE-2024-52004 MediaCMS RCE Attempt"; flow:to_server,established; content:"POST"; http_method; content:"/api/media/upload"; http_uri; content:".php"; http_client_body; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade: Upgrade MediaCMS to version 4.1.0 or later.
2. Disable Uploads: If upgrade is not possible, temporarily disable user uploads.
3. Restrict Permissions: Ensure the web server user has minimal permissions (e.g., no write access to system directories).

Long-Term Measures:

1. Input Validation: Implement strict file type validation using content inspection (e.g., python-magic) rather than relying on extensions.
2. Sandboxing: Run media processing in isolated containers (e.g., Docker) with no network access.
3. Regular Audits: Conduct regular security audits and penetration testing.
4. Monitoring: Deploy the detection rules above and monitor for suspicious activity.

Valters IT Signature:
This report was generated by Valters IT DevSecOps & CTI Division. For questions, contact cti@valters-it.com.