v0.2.0 · live
CAPFRAME
← leaderboard/Microsoft Learn MCP/tool · microsoft_docs_fetch

microsoft_docs_fetch

on https://learn.microsoft.com/api/mcp

Severity

critical0
high1
medium2
low0
info0

3 findings on this tool

  1. highssrf surfacef-r8-microsoft_docs_fetch

    Tool `microsoft_docs_fetch` accepts an unconstrained URL / endpoint parameter

    The parameter(s) `url` look like URL or endpoint inputs but carry no `pattern` or `enum` constraint. An agent tricked by an indirect-injection payload can invoke this tool with an internal-service URL (e.g. `http://169.254.169.254/`) to exfiltrate cloud metadata, probe internal APIs, or pivot to services the host can reach but the caller cannot.

    fix: Constrain the URL parameter with an allow-list `enum`, or a `pattern` that restricts scheme and domain. Validate server-side against an allow-list and reject private / loopback / link-local address ranges at the HTTP client level.

    OWASP LLM07NIST MANAGE-2.2ATLAS T0051CAST-02
  2. mediumunconstrained inputf-r1-microsoft_docs_fetch

    Tool `microsoft_docs_fetch` accepts unconstrained string input

    The following string parameter(s) have no `maxLength` constraint: `url`. Unbounded strings let an attacker stuff arbitrary payloads through the tool, including indirect-injection content.

    fix: Add a `maxLength` to each string property, or constrain with an `enum` or `pattern`. Most legitimate tool inputs fit under a few hundred bytes.

    OWASP LLM01NIST MEASURE-2.3ATLAS T0051CAST-03
  3. mediumindirect injectionf-r6-microsoft_docs_fetch

    Tool `microsoft_docs_fetch` fetches external web content -- indirect-injection surface

    Description: "Fetch and convert a Microsoft Learn documentation webpage to markdown format. This tool retrieves the latest complete content of Microsoft documentation webpages including Azure, .NET, Microsoft 365, and other Microsoft technologies. ## When to Use This Tool - When search results provide incomplete information or truncated content - When you need complete step-by-step procedures or tutorials - When you need troubleshooting sections, prerequisites, or detailed explanations - When search results reference a specific page that seems highly relevant - For comprehensive guides that require full context ## Usage Pattern Use this tool AFTER microsoft_docs_search when you identify specific high-value pages that need complete content. The search tool gives you an overview; this tool gives you the complete picture. ## URL Requirements - The URL must be a valid HTML documentation webpage from the microsoft.com domain - Binary files (PDF, DOCX, images, etc.) are not supported ## Output Format markdown with headings, code blocks, tables, and links preserved." -- this tool pulls externally-controlled content into the agent's context window, the canonical indirect-injection vector. Even when the user supplies the URL, content at that URL can carry hostile instructions.

    fix: Sandbox the fetched content: strip prompts before forwarding to the model, constrain to an allow-list of domains, and route through capframe-guard with a `domain in [...]` caveat.

    OWASP LLM01NIST MEASURE-2.3ATLAS T0051CAST-02

About this tool

microsoft_docs_fetch is one of 3 tools exposed by Microsoft Learn MCP. The server scored 88/100 overall against the capframe rule engine (source: http). Last scanned 2026-07-20.

The findings above are emitted by the public capframe.findings.v1 schema. Disagree with one? Open an issue.