AI agents use nanokvm_unmount_iso to create or update resources in NanoKVM MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your NanoKVM MCP Server environment.
Unmounting an ISO image is a reversible operation — the ISO file itself is not deleted, and it can be remounted. This modifies the system state (removes the mounted image) but does not destroy data, making it a Write-level action. However, mid-operation unmounting during an OS install or boot could disrupt a running process, giving it medium severity.
From the tool's definition Unmount the currently mounted ISO image
Documented attack patterns abuse exactly the kind of access nanokvm_unmount_iso gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and NanoKVM MCP Server, and nothing reaches the server without passing your rules. This is the rule we recommend for nanokvm_unmount_iso:
{
"version": "1",
"default": "deny",
"tools": {
"nanokvm_unmount_iso": {
"limits": [
{
"counter": "nanokvm_unmount_iso_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}nanokvm_unmount_iso 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.
Free to start. No card required.
Unmount the currently mounted ISO image. It is categorised as a Write tool in the NanoKVM MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the NanoKVM MCP Server MCP server in PolicyLayer and add a rule for nanokvm_unmount_iso: 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 NanoKVM MCP Server. Nothing to install.
nanokvm_unmount_iso is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the nanokvm_unmount_iso 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.
Set action: deny in the PolicyLayer policy for nanokvm_unmount_iso. 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.
nanokvm_unmount_iso is provided by the NanoKVM MCP Server MCP server (scgreenhalgh/nanokvm-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from NanoKVM MCP Server, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
19 NanoKVM MCP Server tools catalogued and risk-classified — across an index of 43,000+ MCP servers.