| Package | Affected versions | Patched versions |
|---|---|---|
| network-ai | < 5.7.2 | 5.7.2 |
Target: Jovancoding/Network-AI (npm network-ai), latest v5.7.1
Status: the advisory ("Unauthenticated Cross-Origin MCP Tool Invocation via Empty
Default Secret") named three flaws. The fix (5.4.5) closed the CORS flaw
(Access-Control-Allow-Origin is now set only for localhost origins), but left the
empty-default-secret flaw the title is about: the SSE MCP server still defaults to an
empty secret, _isAuthorized() still returns true when the secret is empty, and a
non-loopback bind only warns. So the server still runs fully unauthenticated by
default — any non-browser caller (curl, SSRF, or a 0.0.0.0 bind) can invoke all 22 MCP
tools (config_set, agent_spawn, blackboard_write, token_*) with no credentials.
Class: CWE-306/CWE-862 Missing Authentication — incomplete fix.
Methodology: M1 incomplete-fix audit (anchor = the 5.4.5 fix; sibling-walk on latest v5.7.1, executed).
Severity: High (matches parent; the browser amplifier is removed, so exploitation now
needs non-browser reach — SSRF or a non-loopback bind, which the fix only warns about).
| advisory flaw | latest v5.7.1 |
|---|---|
wildcard CORS (ACAO: *) | FIXED — lib/mcp-transport-sse.ts sets ACAO only when origin matches ^https?://(localhost|127\.0\.0\.1)(:\d+)?$ |
| empty default secret | NOT FIXED — bin/mcp-server.ts: secret: process.env['NETWORK_AI_MCP_SECRET'] ?? '' |
_isAuthorized open on empty secret | NOT FIXED — if (!this._opts.secret) return true; |
| require secret / refuse unauth bind | NOT DONE — listen() only process.stderr.write('… WARNING …') on non-loopback bind, then listens anyway |
The advisory's remediation #1 ("Require a non-empty secret at startup … ") was not implemented.
Running one of these products? Scan your site to see whether it exposes a vulnerable version.
Scan my site freeprocess.exit(1)poc/legend-networkai-empty-secret.tsInstantiates the real McpSseServer from the latest lib/ with a mock bridge and the
default (empty) secret, then issues requests (run-log poc/run-log.txt):
POST /mcp no-auth, no-origin (curl/SSRF) -> HTTP 200, dispatched=true
body: {"jsonrpc":"2.0","id":1,"result":{"executed":true,"tool":"config_set"}}
POST /mcp Origin: evil.example.com -> ACAO=undefined (CORS half fixed)
The no-auth request passes _isAuthorized and reaches handleRPC (tool dispatched) — i.e.
unauthenticated tool invocation persists on the latest release; only the browser-CORS read
amplifier was removed.
Run: from a v5.7.1 checkout, npm i then
npx ts-node --transpile-only poc/legend-networkai-empty-secret.ts.
Implement the advisory's remediation #1: refuse to start SSE mode with an empty secret
(unless --stdio), and/or change _isAuthorized to fail closed (an empty configured
secret should mean "deny", not "allow"). The CORS allowlist alone does not authenticate
non-browser callers.
With CORS now localhost-only, the drive-by browser attack is mitigated. The residual
requires a non-browser path to the port: an SSRF on the host, or the operator binding to a
non-loopback address (Docker/remote), which the fix only warns about. The empty secret
remains the shipped default and _isAuthorized still authorizes it.
@Kai Aizen / @SnailSploit — https://snailsploit.com