Flyto2 Core: LLM/API keys leak to an attacker-controlled base_url

Summary

llm.chat reads the operator's provider key from the environment (OPENAI_API_KEY, ANTHROPIC_API_KEY, ...) and sends it in the Authorization: Bearer header to base_url, a parameter the caller controls. base_url is only checked against the SSRF guard, and the guard allows any public host, so pointing base_url at an attacker's server hands them the operator's key. flyto-core's own bounty scale rates "environment access exposing secrets (e.g. ANTHROPIC_API_KEY)" as High.

Affected code

src/core/modules/atomic/llm/chat.py (_call_openai):

base_url = params.get('base_url')            # caller-controlled
if base_url:
    validate_url_with_env_config(base_url)    # SSRF check only; a public attacker host passes
if not api_key:
    api_key = os.getenv('OPENAI_API_KEY')     # operator's key
...
url = (base_url or "https://api.openai.com/v1").rstrip('/') + "/chat/completions"
headers = {"Authorization": f"Bearer {api_key}"}
await client.post(url, headers=headers, json=payload)   # sent to base_url

The same wiring (env key plus caller endpoint) exists in ai.model (which does not even SSRF-check base_url), llm.agent, and vector.connector (QDRANT_API_KEY with a caller url). The SSRF guard is the wrong control here: it stops private targets but does nothing about the key being sent to an attacker's public host.

Reproduction

Save as keyexfil_poc.py, run with PYTHONPATH=src/src python keyexfil_poc.py. It sets an operator k…