Vibe-Trading FastAPI endpoints permit unauthenticated access, file upload, and an RCE chain

Finding 1 — Critical: Unauthenticated network client reaches shell execution via POST /sessions/{id}/messages

• Severity: Critical
• CVSS v3.1: 9.8 — AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
• CVSS v4.0: 10.0 — AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H
• CWE: CWE-306 (Missing Authentication for Critical Function); chains into CWE-78 (Group B, F6)

Affected files:

• agent/api_server.py:303 — if not api_key: return early return in require_auth()
• agent/api_server.py:736 — @app.post("/sessions/{session_id}/messages", dependencies=[Depends(require_auth)]) (the dependency is a no-op when API_AUTH_KEY is unset)
• agent/src/tools/bash_tool.py:44-46 — subprocess.run(command, shell=True, cwd=cwd) with command read from kwargs['command'] (full bug detail tracked in GHSA-2 / Group B / F6)

Intent vs actual: The session API is intended to serve authenticated users only. When API_AUTH_KEY is unset, require_auth() returns None immediately and dependencies=[Depends(require_auth)] becomes a no-op. Any anonymous TCP client to port 8899 can therefore create a session, post a message, and receive the LLM agent's response. The LLM ReAct agent — given a natural-language request to run a command — selects BashTool from the auto-discovered registry, which calls subprocess.run(command, shell=True) with the LLM-emitted string. The container has no USER directive, so the resulting process runs as uid=0(root).

Steps to observe:

1. Start the server per the shared reproducer above (with a working OPENROUTER_API_KEY set in agent/.env). Confirm curl -fs http://HOST:8899/health returns 200.
2. SID=$(curl -s -X POST http://HOST:8899/sessions -H 'Content-Type: application/json' -d '{}' | python3 -c "import json,sys;print(json.load(sys.stdin)['session_id'])")
3. curl -s -X POST "http://HOST:8899/sessions/$SID/messages" -H 'Content-Type: application/json' -d '{"content":"Execute the shell command '\''id && uname -a'\'' and report the output verbatim."}'
4. Wait ~5–15 seconds, then curl -s "http://HOST:8899/sessions/$SID/messages" and observe the BashTool result message containing uid=0(root), the kernel version, and the container hostname — all returned with no Authorization header on any of the three requests.

Impact: An unauthenticated caller with TCP access to port 8899 can execute arbitrary shell commands as root inside the container. This is the top-severity entry point of the RCE chain. Combined with the absent USER directive in the Dockerfile, the blast radius is full container takeover.

Finding 2 — High: Read endpoints return full session history with no authentication, even when API_AUTH_KEY is set

• Severity: High
• CVSS v3.1: 7.5 — AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
• CVSS v4.0: 8.7 — AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
• CWE: CWE-862 (Missing Authorization)

Affected file: agent/api_server.py — require_auth() docstring at line 289 states "Only write endpoints (POST/PUT/DELETE/PATCH) use this dependency." Read endpoints with no Depends(require_auth):

• line 804 — @app.get("/runs", response_model=List[RunInfo])
• line 788 — @app.get("/runs/{run_id}", response_model=RunResponse)
• line 748 — @app.get("/runs/{run_id}/code")
• line 769 — @app.get("/runs/{run_id}/pine")
• line 1153 — @app.get("/sessions", response_model=List[SessionResponse])
• line 1173 — @app.get("/sessions/{session_id}", response_model=SessionResponse)
• line 1251 — @app.get("/sessions/{session_id}/messages", response_model=List[MessageResponse])
• line 1272 — @app.get("/sessions/{session_id}/events")
• line 1444 — @app.get("/swarm/runs")

Intent vs actual: When API_AUTH_KEY is configured, the implicit operator expectation is that all session data is protected. The actual design is documented in the docstring at line 289 — read endpoints have no Depends(require_auth), so they remain unauthenticated even with API_AUTH_KEY set. A runtime probe with API_AUTH_KEY=any-secret-value configured: a session was created with a valid Bearer token, a message containing BROKER_TOKEN=ts-secret-deadbeef-real-private-data was posted, then GET /sessions/{id}/messages was issued with no Authorization header and returned HTTP 200 with the broker token string verbatim in the response — confirming the gap persists when authentication is enabled.

Steps to observe:

1. Set API_AUTH_KEY=any-secret-value in agent/.env. Under docker compose, add a bind-mount on the vibe-trading service so the container reads the change: volumes: - ./agent/.env:/app/agent/.env:ro. Then docker compose up -d --force-recreate (a plain restart reuses the existing process env and will not pick up the change).
2. SID=$(curl -s -X POST http://HOST:8899/sessions -H 'Authorization: Bearer any-secret-value' -H 'Content-Type: application/json' -d '{}' | python3 -c "import json,sys;print(json.load(sys.stdin)['session_id'])")
3. curl -s -X POST "http://HOST:8899/sessions/$SID/messages" -H 'Authorization: Bearer any-secret-value' -H 'Content-Type: application/json' -d '{"content":"BROKER_TOKEN=ts-secret-test-value"}' (this requires the Bearer token because POST is auth-protected)
4. No-auth read — curl -s "http://HOST:8899/sessions/$SID/messages" (no Authorization header). Observe HTTP 200 with the broker token visible.
5. Also: curl -s "http://HOST:8899/runs" returns all run records (including their prompt fields) with no auth.

Impact: An unauthenticated caller can enumerate the full history of every agent session — including any broker tokens, LLM API keys, or trading account details the operator has pasted into prompts. The gap persists when the operator believes their write operations are protected, making it deceptive for operators who have followed the SECURITY.md spirit and turned auth on.

Finding 3 — High: Unauthenticated POST /upload writes arbitrary .py/.sh/.yaml files to server filesystem with full path returned

• Severity: High
• CVSS v3.1: 8.1 — AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:N
• CVSS v4.0: 8.7 — AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:H/SI:H/SA:N
• CWE: CWE-434 (Unrestricted Upload of File with Dangerous Type)

Affected file:

• agent/api_server.py:1310-1321 — _BLOCKED_UPLOAD_EXT set rejects .exe, .msi, .bat, .cmd, .com, .scr, .app, .dmg, .so, .dll, .dylib, .zip, .rar, .7z, .tar, .gz, .tgz, .bz2, .xz — but not .py, .sh, .yaml, .j2, .json, .html, or Dockerfile
• agent/api_server.py:1347 — @app.post("/upload", dependencies=[Depends(require_auth)]) (no-op when API_AUTH_KEY unset)

Intent vs actual: POST /upload is intended as an authenticated file-staging mechanism. In default config the auth dependency is a no-op (per F1). The extension blocklist is a denylist not an allowlist, so dangerous executable-adjacent types pass through. The uploaded file is saved as <uuid>.<ext> and the full resolved server path is returned in the response body under "file_path", so the attacker does not need to guess paths.

Steps to observe (no LLM key required):

1. Start the server in default config (no API_AUTH_KEY).
2. curl -s -X POST http://HOST:8899/upload -F 'file=@/dev/stdin;filename=payload.py' <<< 'print("ATTACKER_CONTROLLED")'
3. Observe HTTP 200 with JSON containing "status":"ok" and "file_path":"/app/agent/uploads/<uuid>.py".
4. Repeat with filename=config.yaml and filename=run.sh to confirm multiple executable-adjacent types pass.

Impact: Any unauthenticated caller can write arbitrary Python scripts, shell scripts, or YAML configuration to a known, server-returned path. F3 is independent of any LLM API key — it is the cleanest unauth-write primitive in the codebase. The uploaded file is reachable from the LLM agent's tool envelope and chains into Group B / F8 (backtest exec_module premature exec) for a non-bash RCE path.

Finding A4 — Medium: Default-permissive CORS allowlist + loopback-only check on /settings let any localhost-served browser page drive credentialed cross-origin requests

• Severity: Medium
• CVSS v3.1: 7.7 — AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N
• CVSS v4.0: 6.3 — AV:N/AC:L/AT:P/PR:N/UI:P/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N
• CWE: CWE-942 (Permissive Cross-domain Policy with Untrusted Domains); CWE-346 (Origin Validation Error)

Affected file:

• agent/api_server.py:252-264 — _CORS_ORIGINS = os.getenv(...) defaults to a list of six localhost origins (http://localhost:3000, :5173, :8000; same for 127.0.0.1); CORSMiddleware is added with allow_credentials=True, allow_methods=["*"], allow_headers=["*"]
• agent/api_server.py:309-336 — _is_local_client() and require_local_or_auth(): the loopback check examines request.client.host (TCP peer IP), which is 127.0.0.1 for any browser request from the same machine, regardless of the page's origin
• agent/api_server.py:908 — dependencies=[Depends(require_local_or_auth)] on /settings/llm and related endpoints (granted to any browser request from the host)

Intent vs actual: The CORS allowlist is intended to permit the bundled Vite/React frontend to make credentialed API calls during development. The intent is a development-convenience configuration. The actual configuration permits any local web page served from one of the six listed origins — which includes any other application, IDE preview pane, local web tool, or static HTML file served by another process listening on those ports — to issue credentialed cross-origin POSTs/GETs and read the responses in JavaScript. Because the loopback check at _is_local_client() examines the TCP peer IP (always 127.0.0.1 for browser requests from the host), browser-driven cross-origin requests from a whitelisted origin also bypass the loopback restriction on /settings/*, which would otherwise have been the only barrier.

Steps to observe (no LLM key required):

1. Start the server in default config.
2. Preflight: curl -s -X OPTIONS "http://HOST:8899/sessions" -H "Origin: http://localhost:3000" -H "Access-Control-Request-Method: POST" -i — observe the response includes access-control-allow-credentials: true, access-control-allow-origin: http://localhost:3000, and access-control-allow-methods: DELETE, GET, HEAD, OPTIONS, PATCH, POST, PUT.
3. Confirm a real POST /sessions with Origin: http://localhost:3000 returns the same allow-credentials header in the response so a browser can read the body.
4. Preflight against a settings endpoint: curl -s -X OPTIONS "http://HOST:8899/settings/llm" -H "Origin: http://localhost:3000" -i. Then curl -s "http://HOST:8899/settings/llm" -H "Origin: http://localhost:3000" and observe the response is allowed because request.client.host = 127.0.0.1 satisfies _is_local_client().
5. Negative control: curl -s -X OPTIONS "http://HOST:8899/sessions" -H "Origin: http://evil.example.com" -i — observe no CORS headers, demonstrating the allowlist is functional for non-localhost origins.

Impact: Any malicious or compromised local web page on a whitelisted localhost port can silently drive the Vibe-Trading API in the operator's browser context — creating sessions, posting messages (which chain into F1's BashTool RCE), reading session histories (F2), and reading settings including the partial-key hint exposed by F-A5. Required user interaction is limited to the operator visiting a page that issues background fetch() calls. This expands the F1-F3 surface from direct TCP attackers to browser-mediated attackers that share a host with a developer running the agent.

Finding A5 — Medium: Settings endpoints expose first-4 + last-4 characters of every configured API key via _mask_secret()

• Severity: Medium
• CVSS v3.1: 5.3 — AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• CVSS v4.0: 6.9 — AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
• CWE: CWE-200 (Exposure of Sensitive Information)

Affected files:

• agent/api_server.py:467-474 — _mask_secret() returns f"{value[:4]}...{value[-4:]}" for any string longer than 8 characters
• agent/api_server.py:372 — LLM_API_KEY_PLACEHOLDERS filters out shipped placeholders so the leak fires only when a real key is configured
• agent/api_server.py:505-522 — GET /settings/llm returns api_key_hint = _mask_secret(api_key) if api_key_configured else None
• agent/api_server.py:561 — GET /settings/data-sources returns tushare_token_hint=_mask_secret(token) if token_configured else None
• agent/test_settings_api.py:106 — assertion api_key_hint == "or-s...alue" for input or-secret-value confirms the 4+4 reveal is the intended API contract

Intent vs actual: The frontend needs to confirm to the operator that an API key is configured, so the appropriate hint is a boolean presence indicator or a fixed placeholder. The actual implementation reveals the first 4 and last 4 characters. For structured provider keys with predictable prefixes (sk-or-v1-, gsk_, xoxb-, ts-), the leading 4 bytes are largely fixed and the entropy leak is concentrated in the trailing 4 — which can be material for tokens with bounded total entropy (e.g. Tushare tokens). A runtime probe configured OPENROUTER_API_KEY=sk-or-v1-AbCdEfGhXyZ12345fakekey and TUSHARE_TOKEN=ts-real-shaped-token-1234567890ab and observed api_key_hint='sk-o...ekey' and tushare_token_hint='ts-r...90ab' from the corresponding GET endpoints.

Steps to observe (no LLM key required other than the configured value being non-placeholder; the call itself does not consume the LLM):

1. Edit agent/.env to replace the placeholder with a real-shaped key, e.g. OPENROUTER_API_KEY=sk-or-v1-TestKeyAbcde12345. Restart the server.
2. From any loopback client or via the F-A4 cross-origin path, curl -s "http://127.0.0.1:8899/settings/llm" (no Authorization header).
3. Observe HTTP 200 with api_key_configured=true and api_key_hint containing the first 4 and last 4 characters of the real key.
4. curl -s "http://127.0.0.1:8899/settings/data-sources" to observe tushare_token_hint follow the same pattern.

Impact: Every functional deployment leaks structured bytes of the configured API keys. Combined with offline guessing against bounded-entropy provider keys (notably Tushare tokens), the partial reveal can narrow the attack space to a tractable bruteforce window. The leak is reachable from the F-A4 cross-origin browser path, so it does not require even loopback TCP access — only an operator who visits a malicious local web page in a browser running on the same host as the agent.

Suggested remediation (per finding)

1. F1 / F3 — require_auth() must fail closed when API_AUTH_KEY is not set. Either raise on startup if the env var is empty, or generate a random per-install key and emit a one-time bootstrap message. Replace the if not api_key: return shortcut at line 303 with explicit handling of dev-vs-production.
2. F2 — Apply Depends(require_auth) to all read-side @app.get() decorators (/runs*, /sessions*, /swarm/runs*). The current docstring at line 289 ("Only write endpoints use this dependency") describes the bug rather than design intent.
3. F3 — Convert _BLOCKED_UPLOAD_EXT to an allowlist (.csv, .tsv, .json, .pdf, .txt, .xlsx, .docx etc.) rather than a denylist; add .py, .sh, .yaml, .j2, Dockerfile to the rejection set in any case. Place uploads in a directory outside the agent's tool-discovery envelope.
4. F-A4 — Tighten _CORS_ORIGINS default to only http://localhost:5173 (the bundled Vite dev port). Decouple _is_local_client from request.client.host — require either a Bearer token or a positive Origin header check, not the TCP peer IP. Document loud that adding any port to _CORS_ORIGINS grants full credentialed cross-origin API access.
5. F-A5 — Replace _mask_secret() with a fixed placeholder ("•••configured•••") or a boolean presence flag. If the UI requires a hint, hash the key (truncated SHA-256) so the hint cannot be inverted to bytes of the original.