Is Reverie MCP server safe?
- Node.js filesystem read
- Node.js filesystem write/delete
- Node.js network egress
What to do: Nothing here argues against installing it. Grant the capabilities it lists only if you expect the tool to need them.
Reverie MCP server is an npm package analyzed by SkillTotal's deterministic static scanner. The scan found no malicious indicators. It can: filesystem read, filesystem write, install time execution, mcp tools detected and network egress — capabilities are what the code can do, not a verdict on intent. Risk score 0/100 (low).
@knowall-ai/reverie 0.5.3
Automated static-analysis result. It can contain false positives and false negatives, and is not a claim about the intent of Reverie MCP server's authors. Report a false positive.
Behavioral traits
How this component maps to the CSA agentic threat model. Descriptive — it never affects the risk score.
Findings (5)
The component reads files from disk.
fields = fs.readFileSync('/proc/stat', 'utf8').split('\n')[0].trim().split(/\s+/).slice(1, 8).map(Number);for (const line of fs.readFileSync('/proc/meminfo', 'utf8').split('\n')) {const parsed = JSON.parse(fs.readFileSync(file, 'utf8'));
buffer = fs.readFileSync(file);
const observed = fs.readFileSync(lock, 'utf8');
if (fs.readFileSync(stale, 'utf8') === observed) {if (fs.readFileSync(lock, 'utf8') === token) {const lines = fs.readFileSync(file, 'utf8').split('\n').filter((line) => line.trim()).slice(-MAX_LINES);text = fs.readFileSync(file, 'utf8');
Why it matters: Usually legitimate, but worth confirming it can't be steered into reading sensitive files.
Fix: Confirm which files are read and that paths cannot be influenced by untrusted input to reach sensitive locations.
The component writes or deletes files on disk.
fs.appendFileSync(file, JSON.stringify(record) + '\n', { encoding: 'utf8', mode: 0o600 });fs.unlinkSync(stale); // it was the dead lock we saw: reclaimed
fs.unlinkSync(lock);
fs.writeFileSync(tmp, kept.length ? kept.join('\n') + '\n' : '', { encoding: 'utf8', mode: 0o600 });Why it matters: Usually legitimate, but worth confirming the paths can't be controlled by untrusted input.
Fix: Confirm which files are written/deleted and that paths cannot be influenced by untrusted input.
package.json has a 'prepare' script (runs on git/local installs and before publishing).
"prepare": "npm run build",
Why it matters: Usually a build step, but confirm it doesn't fetch or run remote code.
Fix: Usually a legitimate build step; confirm it only builds and does not fetch or execute remote code.
The component makes outbound network requests.
const response = await fetch(url, { ...init, signal: controller.signal, redirect: 'error' });import http from 'node:http';
Why it matters: Usually legitimate, but confirm the destinations are expected and no sensitive data leaves.
Fix: Confirm the destination hosts are expected and that no sensitive data is sent off-host.
An MCP tool surface (manifest or tool definitions) was found.
const transport = new StreamableHTTPServerTransport({ sessionIdGenerator: undefined, enableJsonResponse: true });const server = new Server({ name: 'reverie', version: VERSION }, { capabilities: { tools: {} } });server.setRequestHandler(ListToolsRequestSchema, async () => ({ tools }));server.setRequestHandler(CallToolRequestSchema, async (request) => {const transport = new StdioServerTransport();
Why it matters: Just context — review which tools it offers and their permissions.
Fix: Review the declared MCP tools and their permissions.
How attackers abuse these capabilities
Interactive labs on the attack class behind the rules above. They show the technique, not anything found in Reverie MCP server.
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Scan your own componentHow we determine this: deterministic static analysis (regex + AST), evidence-anchored, no code execution. Methodology →