vLLM: Unauthenticated OOM Denial of Service via Unbounded `n` Parameter in OpenAI API Server

Summary A Denial of Service vulnerability exists in the vLLM OpenAI-compatible API server. Due to the lack of an upper bound validation on the n parameter in the ChatCompletionRequest and CompletionRequest Pydantic models, an unauthenticated attacker can send a single HTTP request with an...