@turbopuffer/turbopuffer-mcp

MCP servers supporting multiple protocols must enforce authentication independently per protocol. Never reuse OAuth tokens across protocol boundaries. Implement protocol-specific middleware with explicit auth checks on every path. Audit auth coverage for all transport types (stdio, SSE, Streamable HTTP, REST). Reference: CVE-2025-6514 demonstrated that auth library vulnerabilities in MCP's OAuth layer cascade to all protocols sharing the same auth middleware.

Replace exec()/execSync() with execFile() and pass arguments as an array, never as a string. Validate all inputs against an allowlist before use in any shell context. For subprocess.run, always pass a list and shell=False.

Remove all dynamic DNS queries where subdomain content is derived from application data, user input, or system information. DNS exfiltration channels are invisible to most monitoring tools and operate even through strict HTTP firewalls. If DNS-based service discovery is required, use a static list of known-good hostnames. Never construct DNS query hostnames by concatenating or encoding application data. Deploy DNS logging (e.g., passive DNS, BIND query logs) and alert on high-entropy subdomain queries.

Never write credentials to shared agent state. Use credential vaults (HashiCorp Vault, AWS Secrets Manager) with per-agent scoped access. Implement OAuth token exchange (RFC 8693) for cross-agent authorization. Redact credentials from all agent outputs before writing to shared memory. Required by OWASP ASI03/ASI07 and MAESTRO L7.

Never forward, share, or embed credentials across trust boundaries. Use OAuth token exchange (RFC 8693) to create scoped, delegated tokens instead of passing original credentials. Never include credentials in tool responses. Required by ISO 27001 A.5.17 and OWASP ASI03.