openedu09 is a local driver, GUI and MCP server for a USB device.

• The MCP HTTP server binds to 127.0.0.1 only by default and enables DNS-rebinding protection.
• --allow-remote (needed for a non-loopback --host) exposes the server on the network without authentication or TLS. Anyone who can reach it can control the scope. With it, add the Host names clients use via --allowed-host NAME[:PORT] (repeatable); other Host headers are rejected. Use it only on a trusted network or behind your own authenticating proxy.
• The stdio-to-HTTP bridge (edu09-mcp forwarding to the GUI) only talks to loopback owner URLs (127.0.0.0/8, ::1, localhost), because owner.json is user-writable; anything else is refused. If the owner's owner.json disappears (owner exited), the bridge reports OwnerGone instead of reusing the old URL (another program may listen on that port now). Forwarded tool calls are limited to 330 s and upstream JSON responses to 8 MiB. --no-bridge disables forwarding.
• The stdio MCP server inherits the privileges of the launching client.
• Calibration and unknown opcodes are gated behind explicit flags and confirmations: the MCP calibrate and calibration_* tools exist only with --allow-calibration, saving needs confirm=true, the zero step needs input_disconnected=true, and reference readings must be typed by the human (the tools forbid agents to invent them). edu09-probe sends nothing beyond read-only commands without --allow-acquire, and unknown opcodes need --allow-unknown plus a typed confirmation.
• export_csv only writes plain *.csv file names inside the server's export directory (no paths, no overwriting unless asked).
• Only one process can own the scope (file lock), so another local program cannot interleave commands with a running GUI or MCP server. The Linux udev rule gives the device to the logged-in desktop user and the plugdev group only (mode 0660).
• Debug recordings (--record) contain the USB reports exchanged with the scope (no credentials); check a file before attaching it to a public issue.

Please do not open a public issue for security problems. Use GitHub's private vulnerability reporting ("Security" tab, "Report a vulnerability") on this repository. Include affected version, steps to reproduce and impact. This is a hobby project; expect a best-effort response.