1mcp
A central proxy server that aggregates multiple upstream MCP (Model Context Protocol) servers, providing a unified interface for downstream clients using the official @modelcontextprotocol/sdk.
0Tools
14Findings
1Stars
Mar 22, 2026Last Scanned
5 critical · 7 high · 1 medium · 1 low findings detected
Security Category Deep Dive
Prompt Injection
Prompt & context manipulation attacks
69
Maturity
14
Rules
5
Sub-Categories
1
Gaps
64%
Implemented
56
Tests
1
Stories
100%3 rules
Injection via tool descriptions and parameter fields
GAP-001Prompt Injection Coverage GapMissing detection coverage for emerging prompt injection attack variants not addressed by current rules
100%4 rules
Hidden instructions via external content and tool responses
100%2 rules
Context window saturation and prior-approval exploitation
100%3 rules
Payload hiding via invisible chars, base64, schema fields
100%2 rules
Injection via prompt templates and runtime tool output
Findings14
5critical
7high
1medium
1low
Critical5
criticalC1Command InjectionMCP03-command-injectionAML.T0054
Pattern "`[^`]+`" matched in source_code: "`Unknown option: ${arg}`" (at position 1801)
Replace exec()/execSync() with execFile() and pass arguments as an array, never as a string. Validate all inputs against an allowlist before use in any shell context. For subprocess.run, always pass a list and shell=False.
criticalL7Transitive MCP Server DelegationMCP06-excessive-permissionsAML.T0054
Pattern "(?:proxy|forward|delegate|relay|bridge).*(?:mcp|tool|request).*(?:server|client|upstream)" matched in source_code: "proxy server that aggregates multiple upstream MCP server" (at position 1995)
MCP servers MUST NOT create client connections to other MCP servers without explicit user disclosure. If delegation is required, declare all downstream servers in the server's capabilities and tool descriptions. Never forward user credentials to sub-servers. Implement a trust boundary between the approved server and any delegated servers. Log all transitive delegations for audit.
criticalQ13MCP Bridge Package Supply Chain AttackMCP10-supply-chainAML.T0054
Pattern "["']@modelcontextprotocol/sdk["']\s*:\s*["'](?:\^|~|\*|latest)" matched in source_code: ""@modelcontextprotocol/sdk": "^" (at position 26922)
MCP bridge packages (mcp-remote, mcp-proxy, @modelcontextprotocol/sdk, fastmcp) are high-value supply chain targets — CVE-2025-6514 (CVSS 9.6) in mcp-remote affected 437,000+ installs. Always pin exact versions (no ^ or ~ ranges). Use lockfiles (package-lock.json, pnpm-lock.yaml, uv.lock). Never run `npx mcp-remote` without version pinning. Verify package integrity with `npm audit` or `pip-audit` before deployment. Reference: CVE-2025-6514, OWASP ASI04.
criticalQ3Localhost MCP Service HijackingMCP07-insecure-configT1557
Pattern "(?:express|fastify|koa|hono).*(?:listen|server)(?!.*(?:host[_\s]?(?:check|valid|verify)|helmet))" matched in source_code: "express.json() middleware with StreamableHTTPServer" (at position 18612)
MCP servers binding to localhost must: (1) validate the Host header to prevent DNS rebinding attacks (CVE-2025-49596), (2) set strict CORS origins instead of wildcard '*', (3) require authentication tokens even for local connections, (4) use random high ports instead of predictable defaults. For stdio transport, validate all input at the JSON-RPC level before processing. Consider using Docker MCP Gateway or similar container isolation.
criticalQ9Agentic Workflow DAG ManipulationMCP05-privilege-escalationAML.T0058
Pattern "(?:next[_\s]?(?:step|node|agent)|route[_\s]?to|redirect[_\s]?to|skip[_\s]?(?:step|node|validation))" matched in source_code: "routeTo" (at position 5052)
MCP tools must NOT modify agentic workflow graphs, execution order, or routing during runtime. Workflow structure should be immutable once execution begins. If dynamic workflow modification is required, implement: (1) approval gates that require human confirmation before graph mutations, (2) integrity checks that validate the workflow graph against a known-good baseline after each step, (3) audit logging of all graph modifications with rollback capability. Reference: arXiv 2602.19555, Trend Micro subgraph impersonation attack (2026).
High7
highK1Absent Structured LoggingMCP09-logging-monitoringAML.T0054
Pattern "console\.(log|warn|error)\s*\(.*(?:tool|request|handler|execute|invoke)" matched in source_code: "console.log(`📋 Listing ${tools.length} aggregated tool" (at position 4605)
Implement structured logging (pino, winston, or equivalent) for all tool call handlers. Every tool invocation should log: timestamp, tool name, caller identity, parameters (sanitized), result status, and duration. Required by ISO 27001 A.8.15, CoSAI MCP-T12, and NIST AI RMF MEASURE 2.6.
highK16Unbounded Recursion / Missing Depth LimitsMCP07-insecure-configAML.T0054
Pattern "function\s+(\w+).*\{[^}]*\1\s*\((?!.*(?:depth|level|limit|max|count|recursi))" matched in source_code: "function showHelp(): void {
console.log(`
1mcp - A central proxy server that aggregates multiple upstream MCP servers
Usage: node dist/main.js [options]
Options:
--port=<number> Server port (default: 3000)
--host=<string> Server host (default: localhost)
--no-cors Disable CORS (" (at position 1934)
Add explicit depth/recursion limits to all recursive operations. Use iterative approaches where possible. Set maximum depth for directory walking (max_depth=10), tree traversal (max_level=20), and agent re-invocation (max_calls=5). Implement circuit breakers that halt after N iterations. Required by EU AI Act Art. 15 (robustness) and OWASP ASI08.
highI15Transport Session SecurityMCP07-insecure-configAML.T0054
Pattern "session[_\s-]?(token|key|id)\s*[:=]\s*(req\.|params\.|query\.|body\.)" matched in source_code: "sessionId = req." (at position 19779)
Use HTTPS for all MCP Streamable HTTP endpoints. Generate cryptographically random session IDs (min 128 bits entropy). Do not accept session IDs from user input (CVE-2025-6515). Validate TLS certificates — do not disable certificate verification.
highK11Missing Server Integrity VerificationMCP10-supply-chainAML.T0054
Pattern "(?:mcp|server|tool)[_\s-]?(?:url|endpoint|address)\s*[:=].*(?:http|ws)(?!.*(?:verify|pin|cert|tls))" matched in source_code: "MCP endpoint: http" (at position 22646)
Implement cryptographic verification for MCP server connections: (1) Pin server TLS certificates or public keys, (2) Verify server tool definition checksums against a known-good manifest, (3) Use package manager integrity checks (npm integrity, pip --require-hashes). The MCP spec recommends but doesn't yet mandate server signing — implement it proactively. Required by ISO 27001 A.8.24 and CoSAI MCP-T6.
highN3JSON-RPC Request ID CollisionMCP07-insecure-configAML.T0054
Pattern "(?:requestId|request_id|id)\s*[:=]\s*(?:Date\.now|time\.time|int\(time|performance\.now)\s*\(" matched in source_code: "id: Date.now(" (at position 5269)
Use cryptographically random or UUID-based request IDs to prevent collision attacks. Do not use sequential integers — an attacker can predict the next ID and inject a response before the legitimate server responds (response spoofing). Validate that response IDs match pending request IDs. Reference: JSON-RPC 2.0 Section 4.1 — 'id' must be unique within a session.
highN10Incomplete Handshake Denial of ServiceMCP07-insecure-configAML.T0054
Pattern "(?:createServer|listen)\s*\((?!.*(?:maxConnections|maxClients|connectionLimit|MAX_CONN))" matched in source_code: "listen(" (at position 22515)
Enforce a handshake timeout (recommended: 30 seconds) — terminate connections that do not complete the initialize handshake within the deadline. Limit maximum concurrent pending connections. An attacker can exhaust server connection slots by initiating MCP connections without completing the handshake (Slowloris-style attack). Reference: MCP spec 2025-03-26 lifecycle — initialize MUST complete before functional requests.
highD1Known CVEs in DependenciesMCP08-dependency-vuln
Dependency "@modelcontextprotocol/sdk@1.15.1" has known CVEs:
Update dependencies to versions that patch known CVEs. Run 'npm audit fix' or 'pip-audit' to identify and resolve vulnerable dependencies.
Medium1
mediumK17Missing Timeout or Circuit BreakerMCP07-insecure-configAML.T0054
Pattern "(?:fetch|axios|got|request|urllib|httpx|http\.get|http\.post)\s*\((?!.*(?:timeout|signal|AbortSignal|deadline|cancel))" matched in source_code: "Request(" (at position 19981)
Add timeouts to ALL external calls: HTTP requests (30s), database queries (10s), subprocess execution (60s), and MCP tool calls (30s). Implement circuit breakers that open after N consecutive failures (e.g., opossum, cockatiel). Use AbortSignal for cancellable operations. Required by EU AI Act Art. 15 and OWASP ASI08.
Low1
lowF4MCP Spec Non-ComplianceMCP07-insecure-config
Server fails MCP spec compliance checks: required:server_name; required:server_version; required:protocol_version; recommended:tool_descriptions; recommended:parameter_descriptions
Follow the MCP specification for server metadata. Include server name, version, and protocol version. Provide descriptions for all tools and parameters.