One Does Not Simply read_file('/etc/passwd') — Argument Policies Land in Heimdall MCP

The gap Heimdall MCP is a transparent MCP proxy — it sits between your MCP client and any server, records every call as an OpenTelemetry span, and enforces per-server allow/deny policies without touch

blog.cardor.dev5 min read

#agentic-ai #security #llm #mcp #vulnerability

Responses(2)

RS

Richard Smith

May 26

The LOTR title is perfect — argument validation in MCP is no joke, especially when sensitive paths like /etc/passwd are potentially accessible.

V

Varsha

Writing about AI, SaaS, and Modern Product Development

May 27

This is exactly the kind of MCP security issue people overlook. Tool access is powerful, but argument level controls matter just as much. It’s not enough to say “this tool is allowed.” The system also needs to know what inputs should never pass through.

Search Hashnode

One Does Not Simply read_file('/etc/passwd') — Argument Policies Land in Heimdall MCP

Responses(2)