The introduction of Anthropic's open-standard Model Context Protocol (MCP) marks a huge leap forward for AI productivity. MCP allows AI desktop applications and agents to connect natively to local filesystems, PostgreSQL databases, GitHub repositories, Google Drive, and internal developer tools via standardized local servers.
However, granting an LLM direct access to execute local system tools creates an unprecedented attack vector. If an MCP server is improperly configured or exposed to unvetted data, malicious actors can exploit the protocol to perform local privilege escalation, arbitrary code execution, and sensitive file exfiltration.
The Architecture of MCP Vulnerabilities
MCP operates via a client-server model over JSON-RPC (stdio or SSE). An AI assistant (the MCP Client) sends tool execution requests to local or remote binaries (MCP Servers). Key vulnerabilities include:
- Unsanctioned Tool Calling via Indirect Prompt Injection: If an AI agent reads a malicious webpage or email while connected to an MCP filesystem server, the embedded prompt can force the AI to invoke the `write_file` or `execute_command` MCP tool without human consent.
- Over-Privileged Server Binaries: Many community-contributed MCP servers execute with the full privileges of the host user, exposing local SSH keys, environment secrets, and database credentials to the AI model context.
- Lack of Granular Authorization Prompts: Without strict "human-in-the-loop" approval dialogs for every high-risk tool call, automated agents can perform destructive file modifications or API deletions in seconds.
Best Practices for Hardening MCP Deployments
- Enforce strict human confirmation prompts before executing any MCP tool that modifies state or accesses network endpoints.
- Run all MCP server processes in isolated sandbox environments (such as Docker containers or sandboxed user spaces).
- Audit third-party MCP server source code before installation to ensure no hidden telemetry or unauthorized shell access points exist.
- Conduct regular VAPT assessments on internal AI agent integrations with SA Infotech's security team.