Claude-Cursor Bridge
Bridges Claude.ai to Cursor editor for reading files, writing code, and managing selections.
0Tools
9Findings
1Stars
Mar 22, 2026Last Scanned
3 critical · 5 high · 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
50%2 rules1 found
Injection via prompt templates and runtime tool output
Findings9
3critical
5high
1low
Critical3
criticalC1Command InjectionMCP03-command-injectionAML.T0054
Pattern "`[^`]+`" matched in source_code: "`Claude-Cursor MCP Bridge listening on port ${PORT}`" (at position 1456)
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.
criticalJ5Tool Output Poisoning PatternsMCP02-tool-poisoningAML.T0054
Pattern "(error|err|failure|failed).*(?:read|cat|open|access)\s+(?:the\s+)?(?:file|~[/\\]|/etc/|/home/|\.ssh|\.env|\.aws)" matched in source_code: "error: `Cannot read file" (at position 2913)
Tool responses MUST NOT contain instruction-like content, file read directives, or social engineering phrases. Error messages should be factual and technical — never suggest actions involving sensitive data access. See CyberArk ATPA research for attack demonstration.
criticalQ13MCP Bridge Package Supply Chain AttackMCP10-supply-chainAML.T0054
Pattern "(?:mcp|fastmcp|langchain-mcp|llama-index-mcp)(?:>=|~=|==)?(?!\d)" matched in source_code: "MCP" (at position 244)
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.
High5
highN10Incomplete Handshake Denial of ServiceMCP07-insecure-configAML.T0054
Pattern "(?:createServer|listen)\s*\((?!.*(?:maxConnections|maxClients|connectionLimit|MAX_CONN))" matched in source_code: "createServer(" (at position 442)
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.
highN3JSON-RPC Request ID CollisionMCP07-insecure-configAML.T0054
Pattern "(?:onMessage|on_message|handleResponse)\s*(?:=>|=|\()(?!.*(?:pendingRequests|pending_requests|requestMap|expected_id|id\s*===))" matched in source_code: "onMessage(" (at position 304)
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.
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(filepath" (at position 2579)
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.
highK13Unsanitized Tool OutputMCP02-tool-poisoningAML.T0054
Pattern "(?:readFile|read_file|open).*(?:return|respond|result|content|text)(?!.*(?:sanitize|escape|encode|strip|filter|validate|truncate))" matched in source_code: "openText" (at position 2760)
Sanitize all external data before including in tool responses. Implement output encoding that neutralizes prompt injection patterns. Truncate excessively long content. Validate structure before passing database results. Apply the principle: treat all external data as untrusted, even in tool outputs. Required by CoSAI MCP-T4.
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 handleCommand(command, params) {
const editor = vscode.window.activeTextEditor;
switch (" (at position 1729)
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.
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.