Executive brief
Crawl4AI is a web scraping and content extraction tool that can be deployed as a Docker service to crawl websites and extract data. A hardcoded default JWT signing key ("mysecret") in the Docker API server allows attackers to forge authentication tokens for any user without credentials, gaining full access to all protected API endpoints and functionality. This could enable attackers to extract sensitive data, modify configurations, or abuse the crawling service.
Technical details
The vulnerability stems from a hardcoded JWT signing secret ("mysecret") embedded in the public source code of Crawl4AI's Docker API server (CWE-798: Use of Hard-coded Credentials). The JWT token generation mechanism does not validate the strength or uniqueness of the secret key, allowing any attacker with knowledge of the default key to cryptographically sign valid authentication tokens impersonating any user. The attack requires network access to the Docker API endpoint and no prior authentication or user interaction. Once an attacker forges a valid JWT token using the default key, they can access all protected endpoints including data extraction, configuration modification, and potentially destructive operations. The vulnerability was fixed in version 0.8.7 by removing the default key value and implementing startup validation that rejects weak secrets, with auto-generation of an ephemeral key when JWT is enabled but no key is configured.
Affected products
- unclecode Crawl4AI < 0.8.7
Timeline
- 2026-06-21: disclosed
- 2026-06-01: patched: Fix released in v0.8.7