write_kasm_file · Kasm MCP Server v2 MCP: Risk & Policy

WHAT IT DOES

What write_kasm_file does on Kasm MCP Server v2

AI agents use write_kasm_file to create or update resources in Kasm MCP Server v2 — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Kasm MCP Server v2 environment.

WHY IT NEEDS A POLICY

Why write_kasm_file needs a policy

This tool creates or modifies files within Kasm Workspace sessions, which is a reversible write operation. However, the severity is elevated to 'high' rather than 'medium' because: (1) it operates in a containerized environment where an AI agent could write to critical system files, application configs, or inject malicious scripts; (2) when combined with sibling tool 'execute_kasm_command', written files could be…

From the tool's definition Tool name is 'write_kasm_file' and description states 'Write content to a file in a Kasm session.' The verb 'write' combined with 'file' indicates data creation/modification.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

write_kasm_file Rate-limited

write_kasm_file stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "write_kasm_file": {
      "limits": [
        {
          "counter": "write_kasm_file_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Kasm MCP Server v2, so you can run agents against it safely.

FAQ

Questions about write_kasm_file

What does the write_kasm_file tool do? +

Write content to a file in a Kasm session. It is categorised as a Write tool in the Kasm MCP Server v2 MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on write_kasm_file? +

Register the Kasm MCP Server v2 MCP server in PolicyLayer and add a rule for write_kasm_file: 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 Kasm MCP Server v2. Nothing to install.

What risk level is write_kasm_file? +

write_kasm_file is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit write_kasm_file? +

Yes. Add a rate_limit block to the write_kasm_file 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 write_kasm_file completely? +

Set action: deny in the PolicyLayer policy for write_kasm_file. 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 write_kasm_file? +

write_kasm_file is provided by the Kasm MCP Server v2 MCP server (roguedev-ai/kasm-mcp-server-v2). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.