MCPKaliServer

An MCP (Model Context Protocol) server that connects LLMs to a Kali Linux host over SSH for authorized cloud, API and web-application penetration testing.

It exposes your Kali toolbox to any MCP client (Claude Desktop, Claude Code, or your own agent) as a set of well-defined tools organised into the classic pentest phases — Reconnaissance → Service Enumeration → Exploitation — plus health monitoring, a generic command executor, and an engagement-scope guardrail.

⚠️ Authorized use only. This drives offensive security tooling against whatever you point it at. Only use it against systems you have explicit, written permission to test, and configure the scope allow-list to your rules of engagement.

Features

• Secure SSH access to the Kali host with public-key or OpenSSH-certificate authentication, strict known_hosts verification, pooled connection with automatic reconnect. (Password auth is available as a discouraged fallback.)

• Optional mutual TLS (mTLS) on the networked streamable-http transport, so the LLM↔server channel is mutually authenticated.

• Health tool + heartbeat — a background heartbeat probes the SSH connection every 2 minutes; health_check, server_status and list_available_tools report liveness and installed tooling.

• Phase group functions — recon_sweep, enumerate_services, exploit_target orchestrate the common steps of each phase in one call.

• One function per tool — recon_*, enum_*, exploit_* map 1:1 to the underlying Kali tools (nmap, subfinder, httpx, nuclei, ffuf, sqlmap, hydra, ScoutSuite, Pacu, …).

• Generic executor — execute_command / execute_script for anything not covered by a dedicated tool.

• Scope guardrail — every target-taking tool refuses out-of-scope hosts when a scope allow-list is set; exploitation tools are gated by allow_exploitation.

• A Claude skill (skills/cloud-api-pentest-methodology) that teaches the methodology (inspired by Bishop Fox, NetSPI, Rhino Security Labs, with HackerOne as the exploitation reference) and maps every phase to a tool.

Related MCP server: Kali MCP Server

Architecture

   ┌──────────────┐   MCP (stdio or HTTPS+mTLS)   ┌────────────────────┐   SSH (key/cert)   ┌────────────┐
   │  LLM client  │ ─────────────────────────────▶│  MCP Kali Server   │ ──────────────────▶│  Kali host │
   │ (Claude etc.)│ ◀─────────────────────────────│  (this project)    │◀───────────────────│  toolbox   │
   └──────────────┘        tool calls / results    └────────────────────┘   stdout/stderr    └────────────┘
                                                     • heartbeat every 2m
                                                     • scope + exploitation guard

The MCP server runs on your control host (laptop/jump box). It holds the SSH credentials and connects to the Kali host; tools execute remotely over SSH. The LLM never gets shell access directly — it can only call the defined tools.

Requirements

• Control host: Python 3.10+, network access to the Kali host over SSH.

• Kali host: the pentest tooling the tools invoke (install with scripts/install_kali_tools.sh), and SSH access.

Install

git clone https://github.com/ElusiveHacker/MCPKaliServer.git
cd MCPKaliServer
./install.sh          # creates .venv, installs the package, copies config.example.yaml -> config.yaml

Then install the tooling the server drives on the Kali host. Two ways:

• From the LLM, over SSH (recommended): once the server is connected, call the install_kali_tools tool (it runs the installer remotely with sudo). Then call list_available_tools to confirm.

• Manually on the box:

  scp scripts/install_kali_tools.sh kali@<kali-host>:
  ssh kali@<kali-host> 'sudo bash install_kali_tools.sh'

Verify tooling any time from the client by calling the list_available_tools tool.

Configure

Copy and edit config.yaml (created by install.sh), or supply everything via environment variables (.env.example). Env vars override the YAML file and are the recommended way to pass secrets.

Minimum viable config:

transport: stdio
ssh:
  host: 10.0.0.10
  port: 22
  username: kali
  private_key: ~/.ssh/id_ed25519
  known_hosts: ~/.ssh/known_hosts
scope:
  - "*.example.com"      # your in-scope targets
allow_exploitation: true

Key settings:

SSH authentication

Key + OpenSSH certificate (recommended). Generate a CA, client key and signed user certificate:

scripts/gen_ssh_cert.sh kali ./ssh-certs      # principal = remote user

Trust the CA on the Kali host (the script prints the exact commands):

sudo cp ssh-certs/ssh_ca.pub /etc/ssh/mcp_user_ca.pub
echo 'TrustedUserCAKeys /etc/ssh/mcp_user_ca.pub' | sudo tee -a /etc/ssh/sshd_config
sudo systemctl restart ssh

Point the config at the key + certificate:

ssh:
  private_key: ./ssh-certs/id_ed25519
  certificate: ./ssh-certs/id_ed25519-cert.pub

Plain key. Omit certificate and use any key the Kali host authorizes (ssh-copy-id). Host verification: keep strict_host_key_checking: true and make sure the Kali host key is in your known_hosts (ssh-keyscan -H <host> >> ~/.ssh/known_hosts).

mTLS (for the networked transport)

Generate a CA + server/client certificates:

scripts/gen_mtls_certs.sh <server-hostname-or-ip> ./certs

Enable it:

transport: streamable-http
http:
  host: 0.0.0.0
  port: 8000
  tls_cert: certs/server.crt
  tls_key:  certs/server.key
  tls_client_ca: certs/ca.crt   # requiring a client cert = mTLS

The client must present certs/client.crt + certs/client.key. Test with:

curl --cacert certs/ca.crt --cert certs/client.crt --key certs/client.key https://<host>:8000/mcp

Run

source .venv/bin/activate
mcp-kali-server --config config.yaml                 # uses transport from config
mcp-kali-server --config config.yaml -t streamable-http
mcp-kali-server -v                                   # debug logging (to stderr)

Logs go to stderr (stdout is reserved for the stdio MCP protocol).

Connecting a client

Claude Desktop / Claude Code (stdio)

Add to your MCP client config (e.g. Claude Desktop claude_desktop_config.json, or claude mcp add):

{
  "mcpServers": {
    "kali": {
      "command": "/path/to/MCPKaliServer/.venv/bin/mcp-kali-server",
      "args": ["--config", "/path/to/MCPKaliServer/config.yaml"],
      "env": {
        "MCP_KALI_SSH_PASSPHRASE": "<key passphrase if any>"
      }
    }
  }
}

Claude Code CLI equivalent:

claude mcp add kali -- /path/to/.venv/bin/mcp-kali-server --config /path/to/config.yaml

Networked (streamable-http + mTLS)

Run the server with the streamable-http transport and point an mTLS-capable MCP client at https://<host>:8000/mcp with the client certificate/key.

Using the skill

The repo ships a Claude skill at skills/cloud-api-pentest-methodology. It documents the phase-by-phase methodology and tells the model which MCP tool to use for each step, so you can drive an engagement in natural language.

Claude Code / claude.ai: copy the skill folder into your skills directory:

mkdir -p ~/.claude/skills
cp -r skills/cloud-api-pentest-methodology ~/.claude/skills/

(or a project-local .claude/skills/). The skill activates when you ask about planning or running a cloud/API/web pentest. With the kali MCP server connected, the model reads the methodology from the skill and executes it through the tools.

Example prompts once both are loaded:

• "Run a recon sweep of app.example.com and summarise the live services."

• "Enumerate services on the hosts you found; focus on the web app at https://app.example.com."

• "We found a ?id= parameter — validate SQL injection safely and show only the DB banner and current user."

• "Audit the AWS account configuration with ScoutSuite and list the highest-risk findings."

The model will call health_check / list_available_tools, then the appropriate recon_* / enum_* / exploit_* tools, respecting the scope guardrail.

Tool reference

Health & control health_check · server_status · list_available_tools

Setup / provisioning install_kali_tools — installs/refreshes the required tooling on the Kali host over SSH (apt packages, Go/ProjectDiscovery tools, ScoutSuite/Pacu, cloud_enum, awscli). Components: all or a subset of apt,go,cloud,cloudenum,aws. Needs sudo on the Kali host (pass sudo_password, or configure passwordless sudo). Long-running — verify afterwards with list_available_tools.

Generic execute_command · execute_script

Reconnaissance (group: recon_sweep) recon_nmap_discovery · recon_dns_records · recon_dns_enum · recon_subdomains · recon_whois · recon_http_probe · recon_web_crawl · recon_wayback_urls · recon_osint · recon_cloud_assets · recon_ssl_info

Service enumeration (group: enumerate_services) enum_nmap_services · enum_web_tech · enum_web_nikto · enum_dir_bruteforce · enum_vhosts · enum_parameters · enum_nuclei · enum_api_routes · enum_smb · enum_cms_wordpress · enum_cloud_config · enum_ssl_ciphers

Exploitation (group: exploit_target, gated by allow_exploitation) exploit_sqlmap · exploit_nuclei · exploit_bruteforce · exploit_command_injection · exploit_metasploit · exploit_aws_pacu · exploit_aws_cli

Each tool returns { command, exit_status, success, timed_out, stdout, stderr, truncated }. Group functions return a steps map of per-step results.

Security notes

• Scope & consent — set scope; the server refuses out-of-scope targets. This is a guardrail, not a substitute for a signed authorization.

• Least privilege — give the Kali SSH user only what the engagement needs; prefer certificates with a bounded validity (gen_ssh_cert.sh sets ~1 year).

• Secrets — never commit config.yaml, keys or certs; .gitignore already excludes them. Pass secrets via environment variables where possible.

• Exploitation off-switch — set allow_exploitation: false for recon/enum engagements to disable every exploit_* tool.

• Generic executor — execute_command/execute_script are intentionally unrestricted (operator escape hatch) and are not scope-checked. Treat access to this MCP server as equivalent to shell access on the Kali host.

Development

source .venv/bin/activate
pip install -e ".[dev]"
pytest -q            # smoke tests (no Kali host required)

Project layout:

mcp_kali_server/
  __main__.py        CLI entry point + transport/TLS selection
  config.py          layered config (defaults < YAML < env)
  ssh_client.py      asyncssh transport (key/cert auth, reconnect)
  guard.py           engagement-scope enforcement
  health.py          health state + 2-minute heartbeat loop
  installer.py       builds the remote Kali tooling-install script
  server.py          FastMCP assembly, lifespan, health tools
  runtime.py         shared singletons
  tools/
    setup.py         install_kali_tools
    generic.py       execute_command / execute_script
    recon.py         reconnaissance tools + recon_sweep
    enumeration.py   enumeration tools + enumerate_services
    exploitation.py  exploitation tools + exploit_target
skills/cloud-api-pentest-methodology/   the methodology skill
scripts/             install_kali_tools.sh, gen_ssh_cert.sh, gen_mtls_certs.sh

License

MIT — see pyproject.toml. Use responsibly and legally.