APIDetector

APIDetector is a powerful and efficient tool designed for testing exposed Swagger endpoints in various subdomains with unique smart capabilities to detect false-positives. It's particularly useful for security professionals and developers who are engaged in API testing and vulnerability scanning. Presented at BlackHat Arsenal 2024 (https://www.blackhat.com/us-24/arsenal/schedule/index.html#apidetector-advanced-swagger-endpoint-detection-and-vulnerability-analysis-39649)

New in Version 2

APIDetector v2, launched at Blackhat Arsenal, automatically detects vulnerable Swagger versions with XSS and creates a proof of concept (PoC). The apidetectorv2.py file has been added to the repository to support this new feature.

Requirements

To use the new version, install the required packages:

pip install playwright nest_asyncio

Then, install Playwright:

playwright install

Features

• Flexible Input: Accepts a single domain or a list of subdomains from a file.
• Multiple Protocols: Option to test endpoints over both HTTP and HTTPS.
• Concurrency: Utilizes multi-threading for faster scanning.
• Customizable Output: Save results to a file or print to stdout.
• Verbose and Quiet Modes: Default verbose mode for detailed logs, with an option for quiet mode.
• Custom User-Agent: Ability to specify a custom User-Agent for requests.
• Smart Detection of False-Positives: Ability to detect most false-positives.
• Automatic PoC Generation: Detects vulnerable Swagger versions and generates a PoC image automatically.

Getting Started

Prerequisites

Before running APIDetector, ensure you have Python 3.x and pip installed on your system. You can download Python here.

Installation

Clone the APIDetector repository to your local machine using:

git clone https://github.com/brinhosa/apidetector.git
cd apidetector
pip install requests

Usage

Run APIDetector using the command line. Here are some usage examples:

• Common usage, scan with 30 threads a list of subdomains using a Chrome user-agent and save the results in a file:

  python apidetector.py -i list_of_company_subdomains.txt -o results_file.txt -t 30 -ua "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36"

• To scan a single domain:

  python apidetector.py -d example.com

• To scan multiple domains from a file:

  python apidetector.py -i input_file.txt

• To specify an output file:

  python apidetector.py -i input_file.txt -o output_file.txt

• To use a specific number of threads:

  python apidetector.py -i input_file.txt -t 20

• To scan with both HTTP and HTTPS protocols:

  python apidetector.py -m -d example.com

• To run the script in quiet mode (suppress verbose output):

  python apidetector.py -q -d example.com

• To run the script with a custom user-agent:

  python apidetector.py -d example.com -ua "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/90.0.4430.212 Safari/537.36"

If you are using APIDetector v2, replace the commands by apidetectorv2.py.

Options

• -d, --domain: Single domain to test.
• -i, --input: Input file containing subdomains to test.
• -o, --output: Output file to write valid URLs to.
• -t, --threads: Number of threads to use for scanning (default is 10).
• -m, --mixed-mode: Test both HTTP and HTTPS protocols.
• -q, --quiet: Disable verbose output (default mode is verbose).
• -ua, --user-agent: Custom User-Agent string for requests.

Risk Details of Each Endpoint APIDetector Finds

Exposing Swagger or OpenAPI documentation endpoints can present various risks, primarily related to information disclosure. Here's an ordered list based on potential risk levels, with similar endpoints grouped together APIDetector scans:

1. High-Risk Endpoints (Direct API Documentation):

• Endpoints:
  • '/swagger-ui.html', '/swagger-ui/', '/swagger-ui/index.html', '/api/swagger-ui.html', '/documentation/swagger-ui.html', '/swagger/index.html', '/api/docs', '/docs', '/api/swagger-ui', '/documentation/swagger-ui'
• Risk:
  • These endpoints typically serve the Swagger UI interface, which provides a complete overview of all API endpoints, including request formats, query parameters, and sometimes even example requests and responses.
  • Risk Level: High. Exposing these gives potential attackers detailed insights into your API structure and potential attack vectors.

2. Medium-High Risk Endpoints (API Schema/Specification):

• Endpoints:
  • '/openapi.json', '/swagger.json', '/api/swagger.json', '/swagger.yaml', '/swagger.yml', '/api/swagger.yaml', '/api/swagger.yml', '/api.json', '/api.yaml', '/api.yml', '/documentation/swagger.json', '/documentation/swagger.yaml', '/documentation/swagger.yml'
• Risk:
  • These endpoints provide raw Swagger/OpenAPI specification files. They contain detailed information about the API endpoints, including paths, parameters, and sometimes authentication methods.
  • Risk Level: Medium-High. While they require more interpretation than the UI interfaces, they still reveal extensive information about the API.

3. Medium Risk Endpoints (API Documentation Versions):

• Endpoints:
  • '/v2/api-docs', '/v3/api-docs', '/api/v2/swagger.json', '/api/v3/swagger.json', '/api/v1/documentation', '/api/v2/documentation', '/api/v3/documentation', '/api/v1/api-docs', '/api/v2/api-docs', '/api/v3/api-docs', '/swagger/v2/api-docs', '/swagger/v3/api-docs', '/swagger-ui.html/v2/api-docs', '/swagger-ui.html/v3/api-docs', '/api/swagger/v2/api-docs', '/api/swagger/v3/api-docs'
• Risk:
  • These endpoints often refer to version-specific documentation or API descriptions. They reveal information about the API's structure and capabilities, which could aid an attacker in understanding the API's functionality and potential weaknesses.
  • Risk Level: Medium. These might not be as detailed as the complete documentation or schema files, but they still provide useful information for attackers.

4. Lower Risk Endpoints (Configuration and Resources):

• Endpoints:
  • '/swagger-resources', '/swagger-resources/configuration/ui', '/swagger-resources/configuration/security', '/api/swagger-resources', '/api.html'
• Risk:
  • These endpoints often provide auxiliary information, configuration details, or resources related to the API documentation setup.
  • Risk Level: Lower. They may not directly reveal API endpoint details but can give insights into the configuration and setup of the API documentation.

Summary:

• Highest Risk: Directly exposing interactive API documentation interfaces.
• Medium-High Risk: Exposing raw API schema/specification files.
• Medium Risk: Version-specific API documentation.
• Lower Risk: Configuration and resource files for API documentation.

Recommendations:

• Access Control: Ensure that these endpoints are not publicly accessible or are at least protected by authentication mechanisms.
• Environment-Specific Exposure: Consider exposing detailed API documentation only in development or staging environments, not in production.
• Monitoring and Logging: Monitor access to these endpoints and set up alerts for unusual access patterns.

Contributing

Contributions to APIDetector are welcome! Feel free to fork the repository, make changes, and submit pull requests. Special thanks to the contributing members who helped with testing and features suggestions:

• Denis Lourenço
• Bruno Francisco Cardoso

Legal Disclaimer

The APIDetector tool is strictly intended for testing and educational purposes only. The developers of APIDetector assume no liability and disclaim all responsibility for any misuse, unintended consequences, or damage caused by the use of this tool. Any unauthorized, illegal, or otherwise harmful use of APIDetector is expressly prohibited. The end user bears full responsibility for ensuring compliance with all relevant local, state, federal, and international laws. By using this tool, the user acknowledges that they hold the necessary authorizations to test the networks or systems they intend to scan and agrees to indemnify the developers against any and all claims arising from its use. The end user is solely responsible for ensuring that their use of this tool does not violate any legal restrictions or terms of service governing the networks or systems under test.

Disclaimer: APIDetector Tool Usage The APIDetector tool is exclusively designed for lawful testing and educational purposes. It is provided on an "as-is" basis without warranties of any kind, express or implied. The developers and distributors of APIDetector explicitly disclaim any liability for misuse, unintended consequences, or damages resulting from the use of this tool. Important Legal Notice: Unauthorized, illegal, or unethical use of APIDetector is strictly prohibited. Users are solely responsible for adhering to all applicable local, state, federal, and international laws, as well as any terms of service governing the networks or systems they engage with. By using APIDetector, users affirm that they possess the necessary authorizations to test the targeted networks or systems. Assumption of Risk and Indemnification: By downloading, installing, or using APIDetector, the user assumes full responsibility for any legal repercussions associated with its usage. The developers and distributors of APIDetector shall not be held liable for any legal consequences, damages, or third-party claims arising from its use. Users agree to indemnify and hold harmless the developers and distributors against any claims, legal fees, or liabilities associated with their actions.

License

This project is licensed under the MIT License.

Acknowledgments

• Thanks to all the contributors who have helped with testing, suggestions, and improvements.
• Author: Rafael B. Brinhosa - https://www.linkedin.com/in/brinhosa/