Crawl4AI: LLM credential exfiltration in Docker server via request base_url and env: token resolution
Date: 2026-06
Affected: pip/crawl4ai
Attack vector: deserialization
Category: vulnerability-disclosure
Severity: High
CWE: CWE-200
CWE-522
CWE-918
CVSS: 8.2 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N)

### Summary The Docker API server let a request control where LLM calls were sent and which environment variable an LLM token resolved from. Both could be abused to exfiltrate server-held secrets. The Docker API is unauthenticated by default. ### Vector 1 - attacker base_url `/md`, `/llm`, and `/llm/job` accepted a `base_url` in the request and used it as the LLM endpoint while still attaching the server's configured provider API key. An attacker set `base_url` to a server they control and received the provider key (and any provider keys the server holds) in the inbound request. ### Vector 2 - arbitrary environment variable read via `env:` `LLMConfig(api_token="env:NAME")` resolved `NAME` from the server environment with `os.getenv`. Because request bodies were deserialized into `LLMConfig` (via a crawler config / extraction strategy), an attacker could set `api_token="env:SECRET_KEY"` (or `env:REDIS_PASSWORD`, etc.) and, paired with an attacker `base_url`, exfiltrate that secret. Reading the server's `SECRET_KEY` enables forging authentication tokens. ### Impact Disclosure of LLM provider API keys and other server secrets to an attacker-controlled endpoint; reading the JWT `SECRET_KEY` can lead to authentication bypass. ### Fix - The LLM endpoints ignore a request-supplied `base_url`; the endpoint is always derived server-side from the provider name. The field is still accepted but no longer honored (no breaking 4xx). - `LLMConfig` refuses `env:` resolution of prote


Mitigations:

Architectural layers (MAESTRO):