@hono/node-server has Denial of Service risk when receiving Host header that cannot be parsed

Impact

The application hangs when receiving a Host header with a value that @hono/node-server can't handle well. Invalid values are those that cannot be parsed by the URL as a hostname such as an empty string, slashes /, and other strings.

For example, if you have a simple application:

import { serve } from '@hono/node-server'
import { Hono } from 'hono'

const app = new Hono()

app.get('/', (c) => c.text('Hello'))

serve(app)

Sending a request with a Host header with an empty value to it:

curl localhost:3000/ -H "Host: "

The results:

node:internal/url:775
    this.#updateContext(bindingUrl.parse(input, base));
                                   ^

TypeError: Invalid URL
    at new URL (node:internal/url:775:36)
    at newRequest (/Users/yusuke/work/h/159/node_modules/@hono/node-server/dist/index.js:137:17)
    at Server.<anonymous> (/Users/yusuke/work/h/159/node_modules/@hono/node-server/dist/index.js:399:17)
    at Server.emit (node:events:514:28)
    at Server.emit (node:domain:488:12)
    at parserOnIncoming (node:_http_server:1143:12)
    at HTTPParser.parserOnHeadersComplete (node:_http_common:119:17) {
  code: 'ERR_INVALID_URL',
  input: 'http:///'
}

Patches

The version 1.10.1 includes the fix for this issue. But, you should use 1.11.0, which has other fixes related to this issue. #160 #161

Workarounds

Nothing. Upgrade your @hono/node-server.

References

#159