GHSA-xq7h-vwjp-5vrh: @grackle-ai/powerline Runs Without Authentication by Default

When --token is not provided and GRACKLE_POWERLINE_TOKEN is not set, the PowerLine gRPC server runs with zero authentication. A warning is logged ("NO AUTH (development only)") but nothing prevents deployment in this state. Any client that can reach the PowerLine port can spawn agent sessions, access credential tokens, and execute code.

The default binding is 127.0.0.1 (loopback only), which limits exposure to the local machine. However, if PowerLine is accidentally exposed on a network (e.g., in a container or via port forwarding), the impact is critical.

Affected code:

• packages/powerline/src/index.ts:46 — token defaults to empty string
• packages/powerline/src/index.ts:63-76 — auth interceptor is only added when token is truthy