@cyanheads/pentest-mcp-server
Offline methodology engine and payload workshop for authorized penetration testing, CTF, security research, and education via MCP. STDIO or Streamable HTTP.
7 Tools
Authorized use only. This server is designed for penetration testers, red teamers, CTF players, security researchers, and students working on systems they own or have explicit written authorization to test. Users are solely responsible for ensuring their testing is lawful and appropriately scoped. Unauthorized access to computer systems is illegal โ this server does not and cannot enforce authorization on your behalf.
Dual-audience design. Every offensive technique is paired with detection indicators and mitigations. Blue teamers, developers, and anyone building detection coverage will find the methodology and ATT&CK data as useful as the red team workflows.
Overview
Offline penetration-testing methodology engine: MITRE ATT&CK techniques and threat groups, OWASP Testing Guide methodology, and annotated payload templates for authorized penetration testing, CTF, and security research. Generate a phased testing playbook, map techniques to a target profile, analyze HTTP responses for leakage, and generate or encode payload templates from any MCP client. Runs as a stdio process, a local Streamable HTTP server, or the public hosted endpoint above.
| Tool | Description |
|---|
pentest_guide | Step-by-step authorized-testing methodology playbook for a chosen attack vector, phase-filterable, with detection and mitigation per technique. |
pentest_analyze_response | Analyzes raw HTTP response headers/body from authorized probing for leakage, fingerprinting, and misconfiguration. |
pentest_lookup_technique | Looks up a MITRE ATT&CK technique by ID or keyword, with detection data, mitigations, and procedure examples. |
pentest_lookup_group | Looks up a MITRE ATT&CK threat group or software entry by ID or name, with aliases and technique usage. |
pentest_map_techniques | Ranks ATT&CK techniques and OWASP test cases against a target profile (stack, services, auth type, OS). |
pentest_generate_payloads | Generates annotated payload templates for a vulnerability category and injection context, with optional WAF bypass variants and encoding. |
pentest_encode | Applies an ordered encoding chain to a payload string with decode-path tracing. |
Capability reference
- 15 attack vectors via
vector enum: auth_bypass, idor, ssrf, xss, sqli, xxe, path_traversal, cors, csrf, open_redirect, deserialization, race_condition, ssti, command_injection, jwt_attack
- Optional
target_context (stack, waf, recon_notes) narrows the playbook to stack-specific techniques and WAF-bypass-aware variants
phase filter: all (default), recon, enumeration, exploitation, or post_exploitation
- Every technique carries
detection and mitigation; response also includes owasp_references (WSTG IDs) and attack_technique_ids for cross-referencing
authorized_use_reminder rendered as the first line of every response
nextToolSuggestions pre-filled with payload-generator and ATT&CK-lookup calls derived from the methodology context
- Accepts
response_headers (โค20,000 chars), response_body (โค10,000 chars), status_code (100โ599), and freeform context (โค2,000 chars) โ at least one of headers or body is required
- Detects 10 finding categories (version disclosure, stack traces, internal paths, debug headers, technology fingerprints, auth patterns, CORS misconfiguration, missing security headers, interesting fields, error messages), each with
severity (info/low/medium/high)
- Each finding carries
detection and remediation; results are ordered by severity descending
fingerprints block (server_software, framework, language, database, cloud_provider, other) ready for use as target context in pentest_guide or pentest_map_techniques
- Typed
no_input error when neither response_headers nor response_body is supplied
nextToolSuggestions pre-filled from detected fingerprints and findings
- Accepts an exact ATT&CK ID (
T1190, T1059.001) or a keyword; ID lookup is exact, keyword falls back to best-match search
- Returns tactics, platforms, description, detection (
summary, data_sources, indicators), mitigations, and procedure examples from public ATT&CK reporting
include_subtechniques (default true) toggles sub-technique inclusion
attack_version echoes the embedded ATT&CK dataset version (e.g. "Enterprise v19.1") on every response
- Typed
no_match error when the ID or keyword resolves to nothing
- Accepts an exact ATT&CK group ID (
G0007) or software ID (S0002), or a name/keyword (APT28, Mimikatz)
type discriminates group (intrusion set) from software (malware/tool); aliases lists known alternate names
techniques_used returns up to 20 techniques with procedure-level context, each linking to pentest_lookup_technique by technique_id
description truncated to 800 characters
- Typed
no_match error when the ID or name resolves to nothing
- Profile inputs:
stack (array), services (array), auth_type (jwt/session_cookie/api_key/oauth2/basic_auth/ntlm/kerberos/none/unknown), os (linux/windows/macos/unknown) โ at least one required
- Relevance scoring adds points for platform, stack, service, and auth-type matches; each result's
relevance_rationale lists exactly which criteria matched
limit caps ranked_techniques at 1โ50 (default 15); enrichment (truncated, shown, cap) discloses when results were capped
- Each ranked technique carries
detection_opportunity, mitigation_summary, and an optional pentest_guide_vector for follow-up
owasp_test_cases returns up to 10 relevant OWASP Testing Guide test cases
- Typed
no_profile error when no profile field is supplied
- 14 payload categories (
xss, sqli, ssrf, xxe, path_traversal, ssti, command_injection, open_redirect, csrf, deserialization, jwt, ldap_injection, nosql_injection, http_header) ร 16 injection contexts (html_attribute, html_body, js_string, js_template, js_script_block, url_parameter, url_path, sql_where, sql_integer, xml_element, xml_attribute, http_header, json_value, cookie_value, file_name, generic)
waf_profile (cloudflare, aws_waf, modsecurity_crs, imperva, akamai, f5_bigip_asm, nginx_modsecurity, fortinet_fortiwaf, none default, unknown) adds bypass variants referencing public research when set
- Optional
encoding chain applied to each returned template; count caps results at 1โ20 (default 5)
- Each payload carries
detection_signature and mitigation; waf_bypass_note present only when waf_profile isn't none
- Templates are annotated placeholders, not live weaponized strings โ
authorized_use_reminder rendered first in every response
payload string up to 10,000 characters; chain is an ordered list of 1โ6 encoding steps applied left to right
- 10 encoding types:
url, double_url, html_entity, unicode, hex, base64, js_escape, null_byte, mixed_case, comment_break
intermediate_steps traces the value after each chain step; explain (default true) adds decode_path and bypass_rationale
detection_note on every response โ how defenders detect encoded variants
- Pure deterministic transforms, no live probing; typed
encoding_error when a step produces invalid output
Features
Built on @cyanheads/mcp-ts-core: stdio and Streamable HTTP transports, pluggable auth (none / jwt / oauth), swappable storage (in-memory, filesystem, Supabase, Cloudflare KV/R2/D1), structured logging with optional OpenTelemetry tracing.
Methodology-specific:
- Fully offline at runtime โ no external API calls, no credentials required; all data loaded at startup, zero I/O during request handling
- MITRE ATT&CK Enterprise embedded at build time via
scripts/refresh-attack.ts and indexed in memory by ID/keyword; fails fast with an actionable error if the data file is missing
- OWASP Testing Guide methodology and payload template library curated as structured TypeScript modules, one per vector/category
- WAF bypass variants keyed by WAF product and attack vector, referencing public research
- All tools annotated
readOnlyHint: true, openWorldHint: false โ deterministic output from a bounded embedded dataset
Agent-friendly output:
authorized_use_reminder rendered as the first line of content[] on every guide/payload/encoding response โ consistent framing regardless of which surface a client forwards
detection and mitigation fields required (non-optional) on every technique, finding, and payload โ defenders always get usable context alongside offense technique
attack_version echoed on every ATT&CK-backed response so callers can reason about data vintage
nextToolSuggestions pre-filled with arguments derived from the current context, reducing agent planning overhead
Build-time data step
The server embeds MITRE ATT&CK Enterprise data (~20 MB JSON) fetched by a one-time script into a gitignored path. Self-hosters and Docker builders must run this step before the server will start:
bun run scripts/refresh-attack.ts
This downloads the latest ATT&CK Enterprise JSON from the MITRE GitHub release endpoint, writes it to src/data/attack/enterprise.json (gitignored), and updates src/data/attack/version.ts with a version string such as Enterprise v16.1. The version file is committed; the JSON is not (too large for git history).
The Dockerfile handles this automatically โ the build stage runs scripts/refresh-attack.ts before the TypeScript compile, so docker build produces a self-contained image.
If you clone the repo and skip this step, attack-service will fail fast at startup with an actionable error message pointing to scripts/refresh-attack.ts.
Run the script quarterly (or before each release) to pull the latest ATT&CK version.
Getting started
Public Hosted Instance
A public instance is available at https://pentest.caseyjhand.com/mcp โ no installation required. Point any MCP client at it via Streamable HTTP:
{
"mcpServers": {
"pentest-mcp-server": {
"type": "streamable-http",
"url": "https://pentest.caseyjhand.com/mcp"
}
}
}
Self-Hosted / Local
Add the following to your MCP client configuration file.
{
"mcpServers": {
"pentest-mcp-server": {
"type": "stdio",
"command": "bunx",
"args": ["@cyanheads/pentest-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info"
}
}
}
}
Or with npx (no Bun required):
{
"mcpServers": {
"pentest-mcp-server": {
"type": "stdio",
"command": "npx",
"args": ["-y", "@cyanheads/pentest-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info"
}
}
}
}
Or with Docker:
{
"mcpServers": {
"pentest-mcp-server": {
"type": "stdio",
"command": "docker",
"args": [
"run", "-i", "--rm",
"-e", "MCP_TRANSPORT_TYPE=stdio",
"ghcr.io/cyanheads/pentest-mcp-server:latest"
]
}
}
}
For Streamable HTTP, set the transport and start the server:
MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 bun run start:http
Prerequisites
- Bun v1.4.0 or higher (or Node.js v24+).
- ATT&CK data seeded โ run
bun run scripts/refresh-attack.ts once after cloning (Docker builds handle this automatically).
Installation
- Clone the repository:
git clone https://github.com/cyanheads/pentest-mcp-server.git
- Navigate into the directory:
- Install dependencies:
- Seed the ATT&CK data:
bun run scripts/refresh-attack.ts
- Configure environment:
Configuration
No API keys required. The server is fully offline at runtime.
| Variable | Description | Default |
|---|
MCP_TRANSPORT_TYPE | Transport: stdio or http. | stdio |
MCP_HTTP_PORT | Port for HTTP server. | 3010 |
MCP_AUTH_MODE | Auth mode: none, jwt, or oauth. | none |
MCP_LOG_LEVEL | Log level: debug, info, notice, warning, error. | info |
LOGS_DIR | Directory for log files (Node.js only). | <project-root>/logs |
OTEL_ENABLED | Enable OpenTelemetry instrumentation (spans, metrics, completion logs). | false |
See .env.example for the full list of optional overrides.
Running the server
Local development
-
Build and run:
bun run scripts/refresh-attack.ts
bun run rebuild
bun run start:stdio
bun run start:http
-
Run checks and tests:
bun run devcheck
bun run test
bun run lint:mcp
Docker
docker build -t pentest-mcp-server .
docker run --rm -p 3010:3010 pentest-mcp-server
The Dockerfile defaults to HTTP transport, stateless session mode, and logs to /var/log/pentest-mcp-server. OpenTelemetry peer dependencies are installed by default โ build with --build-arg OTEL_ENABLED=false to omit them. The ATT&CK data refresh runs automatically in the build stage.
Project structure
| Directory / File | Purpose |
|---|
src/index.ts | createApp() entry point โ registers tools and initializes services. |
src/services/attack/ | MITRE ATT&CK service โ loads and indexes the embedded enterprise JSON at startup. |
src/services/methodology/ | OWASP Testing Guide methodology service โ vector branches for pentest_guide. |
src/services/payload/ | Payload template service โ keyed by category and injection context. |
src/services/encoding/ | Encoding chain executor โ pure TypeScript transforms. |
src/services/response-analysis/ | Pattern library for information leakage and fingerprinting detection. |
src/mcp-server/tools/definitions/ | Tool definitions (*.tool.ts) โ one file per tool. |
src/data/attack/ | enterprise.json (gitignored, fetched by scripts/refresh-attack.ts) + committed version.ts. |
src/data/owasp/ | Curated OWASP TG v4.2 methodology content as TypeScript modules. |
src/data/payloads/ | Annotated payload templates by vulnerability category. |
src/data/waf-bypass/ | WAF bypass variants keyed by product and attack vector. |
src/data/encodings/ | Encoding transform functions. |
src/data/patterns/ | Regex patterns and metadata for response leakage detection. |
scripts/refresh-attack.ts | Downloads ATT&CK Enterprise JSON and updates the version string. Run once after cloning, then quarterly. |
tests/ | Unit and integration tests mirroring src/. |
docs/design.md | Design document โ tool surface, data strategy, and architectural decisions. |
Development guide
See CLAUDE.md for development guidelines and architectural rules. The short version:
- Handlers throw and the framework catches; catch only to translate an owned operational failure into a declared
ctx.fail contract
- Use
ctx.log for request-scoped logging and keep request handling stateless and deterministic
- Register new tools via the barrel in
src/mcp-server/tools/index.ts
- External source boundary: validate raw data, normalize to a domain type, then return the output schema; never fabricate missing fields
authorized_use_reminder is a required output field on every tool that produces methodology or payload content โ render it as the first line of every content[] response in format()
- Every technique, finding, and payload object has required (non-optional)
detection and mitigation fields โ this is a schema contract, not documentation guidance
Contributing
Issues are welcome. Run checks and tests before submitting:
bun run devcheck
bun run test
License
Apache-2.0 โ see LICENSE for details.