aego-engine-bookwriting

CRITICAL: The `resources/read` method in `bookwriting_server/server_stdio.py` (the primary server implementation invoked by `engine.json`) is vulnerable to path traversal. It constructs a `Path` object directly from the user-provided `file://` URI (e.g., `Path(uri.replace("file://", ""))`) without validating that the resulting path is contained within the designated `book2-root`. This allows an attacker to read arbitrary files on the host filesystem that are accessible to the server process, by simply crafting a URI like `file:///etc/passwd`. The `mcp_resources_read` function in `bookwriting_server/__main__.py` (used for selftests) has the same vulnerability. While `server_fastmcp.py` implements necessary path validation (`is_relative_to`), it is not the configured entry point for this engine.