Klever VM
Klever blockchain smart contract development.
0Tools
12Findings
30Stars
Mar 22, 2026Last Scanned
3 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
Findings12
3critical
7high
1medium
1low
Critical3
criticalC1Command InjectionMCP03-command-injectionAML.T0054
Pattern "`[^`]+`" matched in source_code: "`[WARN] Invalid KLEVER_NETWORK="${envNetwork}". Valid: mainnet, testnet, devnet, local. Defaulting to mainnet.`" (at position 1712)
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.
criticalQ13MCP Bridge Package Supply Chain AttackMCP10-supply-chainAML.T0054
Pattern "["']@modelcontextprotocol/sdk["']\s*:\s*["'](?:\^|~|\*|latest)" matched in source_code: ""@modelcontextprotocol/sdk": "^" (at position 12986)
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 "cors\s*\(\s*\)(?!.*origin)" matched in source_code: "cors()" (at position 2520)
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.
High7
highK1Absent Structured LoggingMCP09-logging-monitoringAML.T0054
Pattern "\b(silent|quiet)\s*[:=]\s*(true|1|yes)" matched in source_code: "quiet: true" (at position 617)
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 startPublicServer() {
// Lazy-import SDK transport types (" (at position 3858)
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.
highQ14Concurrent MCP Server Race ConditionMCP07-insecure-configT1068
Pattern "(?:read|write|modify|delete).*(?:file|path|directory)(?!.*(?:lock|mutex|semaphore|flock|atomic))" matched in source_code: "readFileSync('server.json','utf8'));s.version=process.env.npm_package_version;if(s.packages)s.packages.forEach(p=>p.version=process.env.npm_package_version);fs.writeFile" (at position 12013)
MCP servers sharing filesystem or database backends with other servers must implement proper concurrency controls. Use: (1) file locking (flock/lockfile) for filesystem operations, (2) database transactions for all read-modify-write sequences, (3) atomic file operations (O_EXCL, mkdtemp) instead of check-then-create, (4) lstat() to detect symlinks before following (CVE-2025-53109). Never assume exclusive access to shared resources — other MCP servers may be operating concurrently.
highK11Missing Server Integrity VerificationMCP10-supply-chainAML.T0054
Pattern "(connect|load|register|add)[_\s-]?(mcp|server|tool)(?!.*(?:verify|validate|checksum|hash|sign|cert|fingerprint|pin))" matched in source_code: "add server" (at position 12242)
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.
highK18Cross-Trust-Boundary Data Flow in Tool ResponseMCP04-data-exfiltrationAML.T0054
Pattern "(?:process\.env|os\.environ|config|settings).*(?:fetch|axios|http|post|send|webhook)" matched in source_code: "process.env.MODE || 'http" (at position 10085)
Implement data flow taint tracking: tag data from sensitive sources (databases, credentials, files) and prevent it from flowing to external sinks (HTTP, webhooks, email) without explicit sanitization/redaction. Apply data classification and enforce boundary controls per trust level. Required by ISO 27001 A.5.14 and CoSAI MCP-T5.
highN10Incomplete Handshake Denial of ServiceMCP07-insecure-configAML.T0054
Pattern "(?:createServer|listen)\s*\((?!.*(?:maxConnections|maxClients|connectionLimit|MAX_CONN))" matched in source_code: "listen(" (at position 3265)
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.
highP9Missing Container Resource LimitsMCP07-insecure-configT1499.001
Pattern "(?:for|while)\s*[^}]*(?:fs\.writeFile|open\s*\([^)]*["']w|createWriteStream)(?!.*(?:limit|max|count|quota))" matched in source_code: "format": "prettier --write 'src/**/*.ts'",
"format:check": "prettier --check 'src/**/*.ts'",
"typecheck": "tsc --noEmit",
"test": "node --experimental-vm-modules node_modules/jest/bin/jest.js",
"test:watch": "node --experimental-vm-modules node_modules/jest/bin/jest.js --watch",
"test:coverage": "node --experimental-vm-modules node_modules/jest/bin/jest.js --coverage",
"validate": "pnpm typecheck && pnpm lint && pnpm test",
"ingest": "tsx src/scripts/ingest-knowledge.ts",
"mcp": "MODE=mcp node --experimental-vm-modules dist/index.js",
"dev:mcp": "MODE=mcp STORAGE_TYPE=memory tsx watch src/index.ts",
"start:public": "MODE=public node dist/index.js",
"dev:public": "MODE=public STORAGE_TYPE=memory tsx watch src/index.ts",
"install-sdk": "./scripts/install-sdk.sh",
"version": "node -e \"const fs=require('fs');const s=JSON.parse(fs.readFileSync('server.json','utf8'));s.version=process.env.npm_package_version;if(s.packages)s.packages.forEach(p=>p.version=process.env.npm_package_version);fs.writeFile" (at position 11122)
Always set resource limits for MCP server containers: memory (--memory), CPU (--cpus), PIDs (--pids-limit), file descriptors (--ulimit nofile), and open files. In Kubernetes, set both requests and limits in the container spec. Use LimitRange and ResourceQuota at the namespace level as a safety net. Set pids.max in cgroups to prevent fork bombs. A missing PID limit allows a single tool invocation to fork-bomb the host (CVE-2025-26449 class).
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 7492)
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.