ssh_connect_by_config_host · Ssh Agent MCP: Risk & Policy

WHAT IT DOES

What ssh_connect_by_config_host does on Ssh Agent

AI agents invoke ssh_connect_by_config_host to trigger actions in Ssh Agent. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why ssh_connect_by_config_host needs a policy

Establishing an SSH connection is an Execute-category action as it initiates an external network session that enables subsequent command execution on remote systems. While the connection itself is not destructive or financial, it opens a channel for arbitrary remote execution, giving it high severity due to the blast radius of unauthorized remote access.

From the tool's definition Tool name 'ssh_connect_by_config_host' and server description 'Enables AI assistants to manage SSH connections, execute commands, and transfer files via SFTP' — this tool establishes an SSH connection using a hostname from SSH config file

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ssh_connect_by_config_host Rate-limited

ssh_connect_by_config_host stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "ssh_connect_by_config_host": {
      "limits": [
        {
          "counter": "ssh_connect_by_config_host_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Ssh Agent, so you can run agents against it safely.

FAQ

Questions about ssh_connect_by_config_host

What does the ssh_connect_by_config_host tool do? +

使用SSH config文件中的主机名建立连接. It is categorised as a Execute tool in the Ssh Agent MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on ssh_connect_by_config_host? +

Register the Ssh Agent MCP server in PolicyLayer and add a rule for ssh_connect_by_config_host: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Ssh Agent. Nothing to install.

What risk level is ssh_connect_by_config_host? +

ssh_connect_by_config_host is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit ssh_connect_by_config_host? +

Yes. Add a rate_limit block to the ssh_connect_by_config_host rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block ssh_connect_by_config_host completely? +

Set action: deny in the PolicyLayer policy for ssh_connect_by_config_host. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides ssh_connect_by_config_host? +

ssh_connect_by_config_host is provided by the Ssh Agent MCP server (zhijun/ssh-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.