Linkdave Missing Authentication on REST and WebSocket endpoints

The linkdave server does not enforce authentication on its REST and WebSocket routes in versions prior to 0.1.5.

Impact

An attacker with network access to the server port can:

• Connect to the WebSocket endpoint (/ws) and receive a valid session_id in the OpReady response.
• Use that session to invoke all REST player controls on any guild corresponding to their session id[1].
• Enumerate server statistics and runtime information via the unauthenticated /stats endpoint (still public after the fix).

[1] If on >=0.1.0, attackers are restricted to creating, controlling and deleting players created within their own session ID.

Vulnerable Routes

The following routes were entirely unauthenticated in >= 0.0.1, < 0.1.5:

Method	Path	Description
POST	/sessions/{session_id}/players/{guild_id}/play	Start audio playback
POST	/sessions/{session_id}/players/{guild_id}/pause	Pause playback
POST	/sessions/{session_id}/players/{guild_id}/resume	Resume playback
POST	/sessions/{session_id}/players/{guild_id}/stop	Stop playback
POST	/sessions/{session_id}/players/{guild_id}/seek	Seek to position
PATCH	/sessions/{session_id}/players/{guild_id}/volume	Set volume
DELETE	/sessions/{session_id}/players/{guild_id}	Disconnect from voice channel
GET	/ws	WebSocket event stream

Patches

Update to 0.1.5.

- image: ghcr.io/shi-gg/linkdave:0.1.4
+ image: ghcr.io/shi-gg/linkdave:latest

or

docker pull ghcr.io/shi-gg/linkdave:latest

After upgrading, set the LINKDAVE_PASSWORD environment variable to a strong secret value. If this variable is left unset, the server will still accept all connections without authentication even on >= 0.1.5.

Server configuration (e.g. compose.yml):

environment:
    LINKDAVE_PASSWORD: ${LINKDAVE_PASSWORD}

echo "LINKDAVE_PASSWORD=$(openssl rand -hex 16)" >> .env

To restart the stack, run

docker compose up -d

TypeScript client (0.1.5+):

The client automatically handles authentication. Pass the password when constructing the client:

const linkdave = new LinkDaveClient({
    nodes: [
        {
            name: "main",
            url: process.env.LINKDAVE_URI,
            password: process.env.LINKDAVE_PASSWORD
        }
    ]
});

Workarounds

If upgrading is not immediately possible, restrict network access to the server's port using a firewall so it is only accessible from trusted internal IP addresses.