pki-update-issuer · Vault MCP Server (mschuchard) MCP

WHAT IT DOES

What pki-update-issuer does on Vault MCP Server (mschuchard)

AI agents use pki-update-issuer to create or update resources in Vault MCP Server (mschuchard) — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Vault MCP Server (mschuchard) environment.

WHY IT NEEDS A POLICY

Why pki-update-issuer needs a policy

This tool modifies PKI issuer configuration in Vault, which is reversible (can be updated again or reverted). While the description is empty, the context from the server description and the tool name pattern establish it as a Write operation.

From the tool's definition Tool name 'pki-update-issuer' and parent server's description explicitly mentions 'secret engines like KV v2, PKI, and Transit' with capability to 'manage ACL policies' and 'system backend administration'.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

pki-update-issuer Rate-limited

pki-update-issuer 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": {
    "pki-update-issuer": {
      "limits": [
        {
          "counter": "pki-update-issuer_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 Vault MCP Server (mschuchard), so you can run agents against it safely.

FAQ

Questions about pki-update-issuer

What does the pki-update-issuer tool do? +

pki-update-issuer. It is categorised as a Write tool in the Vault MCP Server (mschuchard) MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on pki-update-issuer? +

Register the Vault MCP Server (mschuchard) MCP server in PolicyLayer and add a rule for pki-update-issuer: 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 Vault MCP Server (mschuchard). Nothing to install.

What risk level is pki-update-issuer? +

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

Can I rate-limit pki-update-issuer? +

Yes. Add a rate_limit block to the pki-update-issuer 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 pki-update-issuer completely? +

Set action: deny in the PolicyLayer policy for pki-update-issuer. 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 pki-update-issuer? +

pki-update-issuer is provided by the Vault MCP Server (mschuchard) MCP server (mschuchard/vault-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.