## Critical Input Validation Flaw in yuzu Gateway Management Service Enables Memory Exhaustion via Unbounded Agent ID Fan-Out
A critical input validation vulnerability in yuzu gateway management service allows an operator—or a compromised operator account—to trigger severe resource exhaustion by submitting an unbounded list of agent IDs with no length cap, format validation, or deduplication. The flaw, present in the `send_command` function of `yuzu_gw_mgmt_service.erl`, permits a single RPC request to target potentially millions of fabricated agent identifiers, forcing the router to attempt fan-out operations that could deplete gateway memory and CPU resources.

The vulnerable code at approximately line 30 of `yuzu_gw_mgmt_service.erl` directly passes the `agent_ids` list from the incoming request to `yuzu_gw_router:send_command` without any sanitization. Unlike a properly hardened implementation, the function accepts raw input from the operator without verifying list length, validating individual ID formats, or checking for duplicate entries. This creates a direct path for abuse: an authenticated operator submits `agent_ids` containing 10,000,000 entries, each a fabricated identifier. The router then iterates the entire list, calling `yuzu_gw_registry:lookup/1` for each ID, receiving `error` responses for every fabricated entry, and accumulating command error messages for each fan-out attempt.

The implications extend beyond simple denial-of-service. Any infrastructure relying on this gateway component faces risk of service degradation or outage if an operator account is compromised or if a malicious insider exploits this design gap. The absence of input bounds checking means even a single malformed request can generate disproportionate load on registry lookups and error-handling paths. Organizations using this service should immediately evaluate mitigations, including request size limits, ID format enforcement, and anomaly detection on agent fan-out operations. The vulnerability underscores a broader pattern of insufficient trust boundaries between operator inputs and backend routing logic.
---
- **Source**: GitHub Issues
- **Sector**: The Lab
- **Tags**: input-validation, denial-of-service, gateway, erlang, vulnerability
- **Credibility**: unverified
- **Published**: 2026-05-10 23:01:48
- **ID**: 81663
- **URL**: https://whisperx.ai/en/intel/81663