# api_jwt_crack

Attempt to crack a JWT token's signing secret.

Agent View of the PolicyLayer registry record for `api_jwt_crack`. HTML page: https://policylayer.com/tools/zebbern-zebbern-kali-mcp/api-jwt-crack

## Facts

- Tool: `api_jwt_crack`
- Server: Zebbern Kali MCP (`zebbern/zebbern-kali-mcp`) — https://policylayer.com/tools/zebbern-zebbern-kali-mcp.md
- Homepage: https://github.com/zebbern/zebbern-kali-mcp
- Risk category: Execute (High risk)
- Registry record: grade F, identity unverified
- Server rate-limited: no
- Parameters: 0
- Recommended policy verdict: Rate-limited

## Example call (MCP tools/call, JSON-RPC 2.0)

```json
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "api_jwt_crack",
    "arguments": {}
  }
}
```

## Why api_jwt_crack is rated High

This tool executes an offensive security operation (JWT secret cracking) against authentication tokens. It runs compute-intensive attack processes within the Kali Linux container. While it does not directly delete data or move money, it enables credential compromise that could lead to full account takeover.

From the tool's own definition: "'Attempt to crack a JWT token's signing secret' — actively runs a cryptographic brute-force/dictionary attack against a JWT signature"

## Use case

AI agents invoke api_jwt_crack to trigger actions in Zebbern Kali MCP. 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.

## Recommended policy (PolicyLayer)

Verdict: **Rate-limited**. Enforced by the PolicyLayer MCP gateway (https://policylayer.com/mcp-gateway) before a call reaches Zebbern Kali MCP:

```json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "api_jwt_crack": {
      "limits": [
        {
          "counter": "api_jwt_crack_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}
```

## Other tools on Zebbern Kali MCP (132)

- `callback_clear` — Destructive — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/callback-clear.md
- `hosts_clear` — Destructive — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/hosts-clear.md
- `hosts_remove` — Destructive — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/hosts-remove.md
- `msf_session_destroy` — Destructive — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/msf-session-destroy.md
- `msf_session_destroy_all` — Destructive — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/msf-session-destroy-all.md
- `pivot_remove` — Destructive — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/pivot-remove.md
- `ad_asreproast` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/ad-asreproast.md
- `ad_bloodhound_collect` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/ad-bloodhound-collect.md
- `ad_kerberoast` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/ad-kerberoast.md
- `ad_ldap_enum` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/ad-ldap-enum.md
- `ad_password_spray` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/ad-password-spray.md
- `ad_psexec` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/ad-psexec.md
- `ad_secretsdump` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/ad-secretsdump.md
- `ad_wmiexec` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/ad-wmiexec.md
- `api_auth_bypass_test` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/api-auth-bypass-test.md
- `api_ffuf_fuzz` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/api-ffuf-fuzz.md
- `api_fuzz_endpoint` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/api-fuzz-endpoint.md
- `api_graphql_fuzz` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/api-graphql-fuzz.md
- `api_kiterunner_scan` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/api-kiterunner-scan.md
- `api_newman_run` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/api-newman-run.md
- `api_nuclei_scan` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/api-nuclei-scan.md
- `api_rate_limit_test` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/api-rate-limit-test.md
- `callback_check` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/callback-check.md
- `callback_generate` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/callback-generate.md
- `callback_latest` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/callback-latest.md
- `callback_start` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/callback-start.md
- `callback_stop` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/callback-stop.md
- `callback_wait` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/callback-wait.md
- `ctf_connect` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/ctf-connect.md
- `ctf_submit_flag` — Execute — https://policylayer.com/tools/zebbern-zebbern-kali-mcp/ctf-submit-flag.md
- …and 102 more: https://policylayer.com/tools/zebbern-zebbern-kali-mcp.md

## For agents

This record is a snapshot. Live verdicts and the full registry:

- Check every server in your MCP config at once: `npx -y policylayer stack`
- Vet a server before you add it: install the mcp-precheck skill — `npx skills add https://policylayer.com` (skill text: https://policylayer.com/skill.md)
- Query the registry over MCP: endpoint `https://api.policylayer.com/mcp` — tools `check_mcp_server`, `check_mcp_stack`, `check_tool`, `search_registry`, `get_change_events`

---

Source: the PolicyLayer MCP registry — one continuously verified record per MCP server. Full record: https://policylayer.com/registry?q=zebbern-zebbern-kali-mcp · API: https://policylayer.com/registry/api · Policy library: https://policylayer.com/policies/zebbern-zebbern-kali-mcp