Remove a stale host key from known_hosts and re-scan the host to add the current key. Use this when you see
AI agents call ssh_known_hosts_fix to permanently remove resources in SSH MCP Server — typically in cleanup and lifecycle workflows. It does its job in a single call, and there is no undo.
An AI agent that decides to call ssh_known_hosts_fix doesn't hesitate, doesn't double-check, and doesn't stop at one. Whatever it removes from SSH MCP Server is gone — there is no undo for destructive operations.
Attacks that exploit this kind of access
Remove a stale host key from known_hosts and re-scan the host to add the current key. Use this when you see. It is categorised as a Destructive tool in the SSH MCP Server MCP Server, which means it can permanently delete or destroy data. Block by default and require explicit approval.
Register the SSH MCP Server MCP server in PolicyLayer and add a rule for ssh_known_hosts_fix: 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 MCP Server. Nothing to install.
ssh_known_hosts_fix is a Destructive tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.
Yes. Add a rate_limit block to the ssh_known_hosts_fix 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 ssh_known_hosts_fix. 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.
ssh_known_hosts_fix is provided by the SSH MCP Server MCP server (yawlabs/ssh-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.