Affected: davila7 claude-code-templates

Claude Code Templates is a CLI tool for configuring and monitoring Claude Code. Prior to 1.29.4, the Claude Code Studio server launched by the --studio option in cli-tool/src/sandbox-server.js binds to all interfaces on port 3444, permits cross-origin requests, and requires no authentication. The POST /api/execute endpoint passes the prompt request-body field to executeLocalTask(), and POST /api/install-agent passes the agentName request-body field to a child process. The same unsafe agent field path is reachable from /api/execute through checkAndInstallAgent(). These attacker-controlled values reach child_process.spawn() with shell execution enabled, causing Node.js to construct a shell command in which metacharacters are interpreted. An attacker who can reach the port directly, or who convinces a developer running Studio to visit a malicious website, can execute arbitrary operating-system commands with the developer's privileges and compromise source code, credentials, and local data. This issue is fixed in version 1.29.4.

Affected: npm: claude-code-templates

### Summary `npx claude-code-templates --studio` launches "Claude Code Studio", an Express HTTP server (`cli-tool/src/sandbox-server.js`, default port 3444) that binds to **all interfaces** (`0.0.0.0`), sets `Access-Control-Allow-Origin: *`, and requires **no authentication**. Two POST endpoints pass attacker-controlled request-body fields into `child_process.spawn(..., { shell: true })`. Because `shell: true` makes Node join the argv array into a single `sh -c` string, the fields are parsed by the shell and metacharacters execute. Any unauthenticated attacker who can reach the port — a malicious web page the developer visits, or anyone on the same LAN — can execute arbitrary OS commands on the developer's machine.

### Details In `cli-tool/src/sandbox-server.js`:

- `app.listen(PORT, ...)` is called with no host argument, so the server listens on `0.0.0.0` / `::` (reachable from the LAN, not just localhost). - The CORS middleware sends `Access-Control-Allow-Origin: *` and answers the preflight `OPTIONS` for any origin, so a browser will deliver cross-origin POSTs to it. - There is no authentication on any endpoint.

The vulnerable sinks:

1. `POST /api/execute` — the `prompt` body field flows into `executeLocalTask()`: ```js const child = spawn('claude', [finalPrompt], { /* ... */ shell: true }); The only validation on prompt is a length check (>= 10 chars). With shell: true, finalPrompt is interpreted by the shell.

2. POST /api/install-agent — the agentName body…