GHSA-hxpf-9xvq-wph8

## REST Path Traversal Bypasses Token Redaction in netlicensing-mcp ### Summary The `netlicensing_get_product` MCP tool in `netlicensing-mcp` interpolates a caller-controlled `product_number` argument directly into a REST URL path without any validation. Passing `../token` as the product number causes `httpx` to normalize `/product/../token` into `/token`, silently redirecting the request to the NetLicensing token endpoint instead of the intended product endpoint. The response is then serialized through the generic `_wrap_json` wrapper rather than the token-specific `_wrap_json_token_read` wrapper, bypassing all APIKEY `number` and SHOP `shopURL` redaction. An authenticated MCP client can recover plaintext API key values that the token read tools intentionally mask, including admin-level APIKEY credentials. ### Details The vulnerability is a path traversal (CWE-22) that exploits the interaction between unsanitized string interpolation and `httpx`'s WHATWG URL normalization. **Source — `src/netlicensing_mcp/tools/products.py:22`** ```python async def get_product(product_number: str) -> dict: """Get a single product by its number.""" return strip_output_fields(await nl_get(f"/product/{product_number}")) ``` `product_number` is inserted directly into the REST path with no validation. A value of `../token` produces the path `/product/../token`. **Sink — `src/netlicensing_mcp/client.py:143`** ```python async def nl_get(path: str, params: dict[str, str] | None = None) -> dict[str, Any]: client = _get_client() url = f"{BASE_URL}{path}" ... r = await client.get(url, headers=_headers(), params=params or {}) ``` `httpx` constructs the full URL as `{BASE_URL}/product/../token` and, per WHATWG URL normalization rules applied to absolute URLs, resolves it to `{BASE_URL}/token`. The HTTP request is therefore sent to the NetLicensing `/core/v2/rest/token` endpoint. **Redaction bypass — `src/netlicensing_mcp/server.py:336` and `src/netlicensing_m