Metadata-Version: 2.4
Name: mcp-security-scanner
Version: 0.1.5
Summary: Security scanner for Model Context Protocol (MCP) servers
Author-email: MCP Scanner <huzaifas@redhat.com>
License:                                  Apache License
                                   Version 2.0, January 2004
                                http://www.apache.org/licenses/
        
           TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
        
           1. Definitions.
        
              "License" shall mean the terms and conditions for use, reproduction,
              and distribution as defined by Sections 1 through 9 of this document.
        
              "Licensor" shall mean the copyright owner or entity authorized by
              the copyright owner that is granting the License.
        
              "Legal Entity" shall mean the union of the acting entity and all
              other entities that control, are controlled by, or are under common
              control with that entity. For the purposes of this definition,
              "control" means (i) the power, direct or indirect, to cause the
              direction or management of such entity, whether by contract or
              otherwise, or (ii) ownership of fifty percent (50%) or more of the
              outstanding shares, or (iii) beneficial ownership of such entity.
        
              "You" (or "Your") shall mean an individual or Legal Entity
              exercising permissions granted by this License.
        
              "Source" form shall mean the preferred form for making modifications,
              including but not limited to software source code, documentation
              source, and configuration files.
        
              "Object" form shall mean any form resulting from mechanical
              transformation or translation of a Source form, including but
              not limited to compiled object code, generated documentation,
              and conversions to other media types.
        
              "Work" shall mean the work of authorship, whether in Source or
              Object form, made available under the License, as indicated by a
              copyright notice that is included in or attached to the work
              (an example is provided in the Appendix below).
        
              "Derivative Works" shall mean any work, whether in Source or Object
              form, that is based on (or derived from) the Work and for which the
              editorial revisions, annotations, elaborations, or other modifications
              represent, as a whole, an original work of authorship. For the purposes
              of this License, Derivative Works shall not include works that remain
              separable from, or merely link (or bind by name) to the interfaces of,
              the Work and Derivative Works thereof.
        
              "Contribution" shall mean any work of authorship, including
              the original version of the Work and any modifications or additions
              to that Work or Derivative Works thereof, that is intentionally
              submitted to Licensor for inclusion in the Work by the copyright owner
              or by an individual or Legal Entity authorized to submit on behalf of
              the copyright owner. For the purposes of this definition, "submitted"
              means any form of electronic, verbal, or written communication sent
              to the Licensor or its representatives, including but not limited to
              communication on electronic mailing lists, source code control systems,
              and issue tracking systems that are managed by, or on behalf of, the
              Licensor for the purpose of discussing and improving the Work, but
              excluding communication that is conspicuously marked or otherwise
              designated in writing by the copyright owner as "Not a Contribution."
        
              "Contributor" shall mean Licensor and any individual or Legal Entity
              on behalf of whom a Contribution has been received by Licensor and
              subsequently incorporated within the Work.
        
           2. Grant of Copyright License. Subject to the terms and conditions of
              this License, each Contributor hereby grants to You a perpetual,
              worldwide, non-exclusive, no-charge, royalty-free, irrevocable
              copyright license to reproduce, prepare Derivative Works of,
              publicly display, publicly perform, sublicense, and distribute the
              Work and such Derivative Works in Source or Object form.
        
           3. Grant of Patent License. Subject to the terms and conditions of
              this License, each Contributor hereby grants to You a perpetual,
              worldwide, non-exclusive, no-charge, royalty-free, irrevocable
              (except as stated in this section) patent license to make, have made,
              use, offer to sell, sell, import, and otherwise transfer the Work,
              where such license applies only to those patent claims licensable
              by such Contributor that are necessarily infringed by their
              Contribution(s) alone or by combination of their Contribution(s)
              with the Work to which such Contribution(s) was submitted. If You
              institute patent litigation against any entity (including a
              cross-claim or counterclaim in a lawsuit) alleging that the Work
              or a Contribution incorporated within the Work constitutes direct
              or contributory patent infringement, then any patent licenses
              granted to You under this License for that Work shall terminate
              as of the date such litigation is filed.
        
           4. Redistribution. You may reproduce and distribute copies of the
              Work or Derivative Works thereof in any medium, with or without
              modifications, and in Source or Object form, provided that You
              meet the following conditions:
        
              (a) You must give any other recipients of the Work or
                  Derivative Works a copy of this License; and
        
              (b) You must cause any modified files to carry prominent notices
                  stating that You changed the files; and
        
              (c) You must retain, in the Source form of any Derivative Works
                  that You distribute, all copyright, patent, trademark, and
                  attribution notices from the Source form of the Work,
                  excluding those notices that do not pertain to any part of
                  the Derivative Works; and
        
              (d) If the Work includes a "NOTICE" text file as part of its
                  distribution, then any Derivative Works that You distribute must
                  include a readable copy of the attribution notices contained
                  within such NOTICE file, excluding those notices that do not
                  pertain to any part of the Derivative Works, in at least one
                  of the following places: within a NOTICE text file distributed
                  as part of the Derivative Works; within the Source form or
                  documentation, if provided along with the Derivative Works; or,
                  within a display generated by the Derivative Works, if and
                  wherever such third-party notices normally appear. The contents
                  of the NOTICE file are for informational purposes only and
                  do not modify the License. You may add Your own attribution
                  notices within Derivative Works that You distribute, alongside
                  or as an addendum to the NOTICE text from the Work, provided
                  that such additional attribution notices cannot be construed
                  as modifying the License.
        
              You may add Your own copyright statement to Your modifications and
              may provide additional or different license terms and conditions
              for use, reproduction, or distribution of Your modifications, or
              for any such Derivative Works as a whole, provided Your use,
              reproduction, and distribution of the Work otherwise complies with
              the conditions stated in this License.
        
           5. Submission of Contributions. Unless You explicitly state otherwise,
              any Contribution intentionally submitted for inclusion in the Work
              by You to the Licensor shall be under the terms and conditions of
              this License, without any additional terms or conditions.
              Notwithstanding the above, nothing herein shall supersede or modify
              the terms of any separate license agreement you may have executed
              with Licensor regarding such Contributions.
        
           6. Trademarks. This License does not grant permission to use the trade
              names, trademarks, service marks, or product names of the Licensor,
              except as required for reasonable and customary use in describing the
              origin of the Work and reproducing the content of the NOTICE file.
        
           7. Disclaimer of Warranty. Unless required by applicable law or
              agreed to in writing, Licensor provides the Work (and each
              Contributor provides its Contributions) on an "AS IS" BASIS,
              WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
              implied, including, without limitation, any warranties or conditions
              of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
              PARTICULAR PURPOSE. You are solely responsible for determining the
              appropriateness of using or redistributing the Work and assume any
              risks associated with Your exercise of permissions under this License.
        
           8. Limitation of Liability. In no event and under no legal theory,
              whether in tort (including negligence), contract, or otherwise,
              unless required by applicable law (such as deliberate and grossly
              negligent acts) or agreed to in writing, shall any Contributor be
              liable to You for damages, including any direct, indirect, special,
              incidental, or consequential damages of any character arising as a
              result of this License or out of the use or inability to use the
              Work (including but not limited to damages for loss of goodwill,
              work stoppage, computer failure or malfunction, or any and all
              other commercial damages or losses), even if such Contributor
              has been advised of the possibility of such damages.
        
           9. Accepting Warranty or Additional Liability. While redistributing
              the Work or Derivative Works thereof, You may choose to offer,
              and charge a fee for, acceptance of support, warranty, indemnity,
              or other liability obligations and/or rights consistent with this
              License. However, in accepting such obligations, You may act only
              on Your own behalf and on Your sole responsibility, not on behalf
              of any other Contributor, and only if You agree to indemnify,
              defend, and hold each Contributor harmless for any liability
              incurred by, or claims asserted against, such Contributor by reason
              of your accepting any such warranty or additional liability.
        
           END OF TERMS AND CONDITIONS
        
           APPENDIX: How to apply the Apache License to your work.
        
              To apply the Apache License to your work, attach the following
              boilerplate notice, with the fields enclosed by brackets "[]"
              replaced with your own identifying information. (Don't include
              the brackets!)  The text should be enclosed in the appropriate
              comment syntax for the file format. We also recommend that a
              file or class name and description of purpose be included on the
              same "printed page" as the copyright notice for easier
              identification within third-party archives.
        
           Copyright [yyyy] [name of copyright owner]
        
           Licensed under the Apache License, Version 2.0 (the "License");
           you may not use this file except in compliance with the License.
           You may obtain a copy of the License at
        
               http://www.apache.org/licenses/LICENSE-2.0
        
           Unless required by applicable law or agreed to in writing, software
           distributed under the License is distributed on an "AS IS" BASIS,
           WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
           See the License for the specific language governing permissions and
           limitations under the License.
        
Description-Content-Type: text/markdown
License-File: LICENSE
Requires-Dist: click>=8.1
Requires-Dist: websockets>=12.0
Requires-Dist: httpx>=0.27
Requires-Dist: httpx-sse>=0.4
Requires-Dist: jsonschema>=4.21
Requires-Dist: pydantic>=2.6
Requires-Dist: rich>=13.7
Requires-Dist: pytest>=8.3
Dynamic: license-file

# MCP Security Scanner

This is a Python-based penetration testing tool for Model Context Protocol (MCP) servers. It supports HTTP, stdio, and experimental SSE transports, runs a suite of checks mapped to `scanner_specs.schema` (auth, transport, tools, prompts, resources), and includes a deliberately insecure MCP-like server for testing.

**Legacy HTTP+SSE transport is deprecated; compatibility support is experimental. Streamable HTTP continues to support SSE responses.**

## Install

### Install a tagged release

Choose a tag from the [releases page](https://github.com/sidhpurwala-huzaifa/mcp-security-scanner/releases).
In an activated virtual environment, replace `<tag>` with your chosen tag:

```bash
python -m pip install --upgrade "git+https://github.com/sidhpurwala-huzaifa/mcp-security-scanner.git@<tag>"
python -c "from mcp_scanner.spec import load_spec; print(f'Loaded {len(load_spec())} checks')"
```

### Install from source

```bash
# 1) Clone
git clone https://github.com/sidhpurwala-huzaifa/mcp-security-scanner
cd mcp-security-scanner

# 2) Create venv (Python >= 3.10)
python -m venv .venv
source .venv/bin/activate

# 3) Install dependencies
pip install -r requirements.txt

# 4) (Optional) Dev install for CLI entrypoints
pip install -e .
```

### Verify release packaging

An editable install can hide missing package data. To check actual distributions
from a clean checkout:

```bash
python -m pip install build
python -m build
python scripts/check_distribution.py dist
```

The check requires one wheel and one source distribution in `dist/`. It verifies
both contain the schema, then installs the wheel into a temporary virtual
environment and loads the default checks outside the checkout. CI runs this check
on pull requests, main-branch pushes, and tag pushes.

## Usage

### Scan outcomes and report compatibility

Reports use `schema_version: 2`. Each finding has an authoritative `status`:

| Status | Meaning | Compatibility field `passed` |
| --- | --- | --- |
| `pass` | The check evaluated its evidence and passed | `true` |
| `fail` | The check evaluated its evidence and failed | `false` |
| `error` | A prerequisite or probe failed; the check could not be evaluated | `null` |
| `skipped` | Not evaluated, with the reason in `details` | `null` |

Existing boolean findings can still be read. JSON consumers must handle `null`
and use `status` instead of treating every false-like `passed` value as a
vulnerability. JSON summaries count `passed`, `failed`, `errors`, and `skipped`
separately; severity totals count only failed checks.

HTTP scans stop dependent probes when initialization fails, report a `BASE-01`
error even if a custom spec omits that check, and skip the dependent checks.
Independent TLS/Origin/bind and OAuth-metadata checks can still run. Failed or
malformed tool, prompt, and resource enumerations produce errors for the checks
that require them. Successful empty enumerations produce explicit skips rather
than security passes. A failed second tool listing is an error, not evidence of
a rug pull. Paginated results with more pages are treated as incomplete until
full enumeration support is implemented.

Exit codes for `scan` and `scan-range` are `0` for completion without failures or
errors, `1` for evaluated failures, and `2` for incomplete scans with errors
(errors take precedence over failures). Expected empty-result skips alone do not
make a scan incomplete. CLI argument errors can also return `2`. Scan summaries
go to stderr in JSON mode so stdout remains the report; verbose traces are human
diagnostics and should not be combined with machine parsing.

HTTP health output uses `status: "ok"` or `"error"`, `initialize_http_status`,
`enumeration_status`, and an `errors` mapping. An unavailable enumeration is
`null`; a successfully retrieved empty enumeration is `[]`. `--only-health`
returns `2` on an error and displays unavailable data explicitly.

### Active probe outcomes

Active checks classify transport outcomes before examining response text for
vulnerability evidence. R-01/R-02 and access-control resource/remote probes accept
HTTP 401/403 as explicit denials; P-01 accepts a well-formed JSON-RPC -32602 error
for intentionally invalid arguments. Other RPC errors and tool `isError` results
are inconclusive. A check with any unexpected probe failure is reported as an
error, even if another attempt in that same check returned data. Independent
checks still retain their own findings; no request is automatically replayed.

### Diagnostics and redaction

HTTP error diagnostics retain server details with a 16 KiB read limit and the
existing time budget. Diagnostic summaries are redacted and bounded. Each scan
keeps an isolated secret set containing supplied credentials and learned session
identifiers (including legacy endpoint tokens); it is shared with verbose traces
and final scan/health/RPC output. Redaction occurs after evidence evaluation so
it does not turn a detected exposure into a pass.

Redaction preserves dictionary keys to keep protocol/report structure intact.
Short secrets (fewer than eight characters) are matched as complete values or
word-delimited tokens, avoiding corruption of ordinary words. Recognized secret
fields and token query parameters remain redacted. Raw and JSON-escaped forms
are deduplicated and replaced in one pass; existing redaction markers are stable.
Substring occurrences of short identifiers inside unrelated words are inherently
ambiguous and are deliberately left unchanged.

### HTTP session handling

Scan, health, and RPC share session handling. `http` selects Streamable HTTP;
`auto` tries it first and falls back to legacy HTTP+SSE only after an initialize
POST returns 404 or 405 and a valid legacy endpoint event is received.
The session accepts JSON or SSE, correlates response IDs, negotiates protocol
2025-06-18 or 2025-03-26, propagates session/version headers, and sends
`notifications/initialized` before normal requests. It advertises no optional
client capabilities. Requests are never automatically replayed after failure.
Streamable HTTP SSE responses close as soon as the matching result arrives. Response data is
limited to 8 MiB, with an elapsed budget checked between response chunks and
HTTPX network timeouts. This is not a strict wall-clock cancellation deadline.
Discovery continues probing lists even if not advertised, as this is a scanner.
Legacy SSE keeps the original GET connection open, posts a real initialize to
the advertised endpoint, and waits for its correlated response on that connection.
A legacy endpoint discovery event alone does not verify MCP initialization. Active probes retain structured HTTP/RPC
outcomes: unexpected HTTP failures, JSON-RPC errors, tool execution errors, and
timeouts produce `error` findings rather than security passes. Independent checks
continue, and incomplete scans retain exit code 2. Check-specific access denials
and invalid-argument rejections remain distinct from infrastructure errors.

### Legacy HTTP+SSE compatibility

- Discovery uses the supplied SSE URL and its `endpoint` event. Query parameter
  names such as `sessionId` never select a transport or fabricate a session header.
- `--sse-endpoint /sse` resolves from the origin root; a relative path resolves
  against `--url`. `auto` uses it only after HTTP initialization returns 404/405.
  Authentication failures, other HTTP failures, malformed initialization, and
  normal RPC failures do not trigger fallback.
- The advertised endpoint must have the same origin, without embedded credentials
  or a fragment. Legacy redirects are rejected; supply the final SSE URL directly.
- Legacy protocol 2024-11-05 initialization, initialized notifications, and normal
  replies use the original SSE connection. Both message bodies and headers are
  handled independently of URL query spelling. Health includes the chosen transport.
- Disconnects, endpoint rotation, missing replies, and invalid initialization
  produce errors. Connections close on success and failure; calls are not replayed
  and streams are not automatically resumed. Start a new scan to reconnect.
- The shared SSE parser handles comments, multiline data, split UTF-8, CR/LF/CRLF,
  and unrelated events. The 8 MiB bound applies to each Streamable HTTP response
  and to the lifetime of a legacy receive stream; elapsed budgets are checked
  between chunks/events alongside network timeouts, not hard wall-clock cancellation.

References: [legacy transport](https://modelcontextprotocol.io/specification/2024-11-05/basic/transports)
and [Streamable HTTP backwards compatibility](https://modelcontextprotocol.io/specification/2025-06-18/basic/transports#backwards-compatibility).

### Quick test
```bash
# Verify CLI is available
mcp-scan --help

# Connection failure example
mcp-scan scan --url http://127.0.0.1:65000
# -> Reports an initialization error if nothing is listening
```

### Run insecure test server (HTTP)
```bash
# Basic (HTTP JSON-RPC). Supports --test modes (Defaults to 0, otherwise choose a vulnerable model from below)
insecure-mcp-server --host 127.0.0.1 --port 9001

# Test modes currently supported
# --test 0 (default): basic insecure MCP-like server
# --test 1: prompt injection-style vulnerable server
# --test 2: tool poisoning-style vulnerable server
# --test 3: rug-pull tool mutation between listings
# --test 4: excessive permissions (admin tools exposed), private:// resource leakage
# --test 5: token theft (server leaks upstream access tokens to clients)
# --test 6: indirect prompt injection (external resource carries hidden instructions)
# --test 7: remote access control exposure (unauth tool enables remote access)

insecure-mcp-server --host 127.0.0.1 --port 9001 --test 0/1/2/3/4/5/6/7
```

### Scan the server (HTTP, stdio, or SSE)
```bash
# HTTP: Text report (--url is the MCP endpoint)
mcp-scan scan --url http://127.0.0.1:9001/mcp --format text

# HTTP: JSON report
mcp-scan scan --url http://127.0.0.1:9001/mcp --format json --output report.json

# HTTP: Verbose tracing (real-time)
mcp-scan scan --url http://127.0.0.1:9001/mcp --verbose

# stdio: Scan local MCP servers via stdin/stdout
mcp-scan scan --transport stdio --command "npx -y @modelcontextprotocol/server-memory" --format json

# SSE: connect to explicit SSE endpoint, then scan via emitted /messages?sessionId=...
mcp-scan scan --url https://your-mcp.example.com --transport sse --sse-endpoint /sse --timeout 30 --verbose
```

### RPC passthrough (Inspector-like)
**Note: RPC commands only support HTTP and SSE transports, not stdio.**

HTTP scanning, RPC, and health checks set `Accept: application/json, text/event-stream`
for MCP requests, replacing HTTPX's default or a custom `Accept` value. Authentication
and other custom headers are preserved. SSE GET requests use `Accept: text/event-stream`.

```bash
# List tools (HTTP)
mcp-scan rpc --url https://your-mcp.example.com/mcp --method tools/list --transport http

# Call a tool (HTTP)
mcp-scan rpc --url https://your-mcp.example.com/mcp \
  --method tools/call \
  --params '{"name":"weather","arguments":{"city":"Paris"}}' \
  --transport http

# With SSE transport
mcp-scan rpc --url https://your-mcp.example.com --method tools/list --transport sse --sse-endpoint /sse
```

### Explanations
- `--explain <ID>` prints a focused explanation for a single finding (e.g., `--explain X-01`). It includes:
  - Test (ID and title)
  - Expected outcome
  - Got (scanner-observed details)
  - Result (why PASS/FAIL)
  - Remediation (from the spec)

Example:
```bash
mcp-scan scan --url https://your-mcp.example.com/mcp --explain X-01
```

### Only health
- `--only-health` prints server details and enumerations without running the full scan.
- Works for HTTP, stdio, and SSE transports.
- Supports `--format text` and `--format json`.

Examples:
```bash
# HTTP
mcp-scan scan --url https://your-mcp.example.com/mcp --only-health --format text

# stdio
mcp-scan scan --transport stdio --command "npx -y @modelcontextprotocol/server-memory" --only-health --format json

# SSE
mcp-scan scan --url https://your-mcp.example.com --transport sse --sse-endpoint /sse --only-health --format json
```

### Authentication
```bash
# Bearer token
mcp-scan scan \
  --url http://your-mcp.example.com/mcp \
  --auth-type bearer \
  --auth-token "$TOKEN"

# OAuth2 Client Credentials
mcp-scan scan \
  --url http://your-mcp.example.com/mcp \
  --auth-type oauth2-client-credentials \
  --token-url https://issuer.example.com/oauth2/token \
  --client-id "$CLIENT_ID" --client-secret "$CLIENT_SECRET" \
  --scope "mcp.read mcp.tools"
```

### Transport, timeouts, session
- **--transport auto|http|stdio|sse**: Select transport explicitly or use the bounded fallback described above.
  - `http`: Requires `--url` for JSON-RPC endpoint
  - `stdio`: Requires `--command` for local MCP server process
  - `sse`: Legacy HTTP+SSE at `--url`; optional `--sse-endpoint` resolves a URL/path against it (experimental).
- **--timeout <seconds>**: Per-request read timeout (default 12s). Increase for slow streams.
- **--session-id <SID>**: Pre-established session (`Mcp-Session-Id` header).

## Testing

### Running Tests
```bash
# Set up environment (if not already done)
python -m venv .venv
source .venv/bin/activate
pip install -r requirements.txt
pip install -e .

# Run all tests
python -m pytest tests/ -v

# Run specific test module
python -m pytest tests/test_stdio_scanner.py -v
python -m pytest tests/test_security_checks.py -v

# Run specific test class
python -m pytest tests/test_stdio_scanner.py::TestStdioIntegration -v
```

### Running with Container

```bash
# Build container

podman build -t mcp-scan .

# Run
podman run --rm mcp-scan scan --url ${MCP_SERVER} --format text
```

## Acknowledgements
- Vulnerability ideas inspired by `Damn Vulnerable MCP Server` - https://github.com/harishsg993010/damn-vulnerable-MCP-server
- Ye Wang from Red Hat for help with MCP server interoperability
