Description

Named path parameters can be overridden in TrieRouter

Impact

The clients may override named path parameter values from previous requests if the application is using TrieRouter. So, there is a risk that a privileged user may use unintended parameters when deleting REST API resources.

TrieRouter is used either explicitly or when the application matches a pattern that is not supported by the default RegExpRouter.

The code to reproduce it. The server side application:

import { Hono } from 'hono'
import { TrieRouter } from 'hono/router/trie-router'

const wait = async (ms: number) => {
  return new Promise((resolve) => {
    setTimeout(resolve, ms)
  })
}...
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The client code which makes requests to the server application:

const examples = [
  'http://localhost:8787/modules/first/versions/first',
  'http://localhost:8787/modules/second/versions/second',
  'http://localhost:8787/modules/third/versions/third',
]

const test = () => {
  for (const example of examples) {...
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The results:

Error: exprected second but got third - url was http://localhost:8787/modules/second/versions/second
Error: exprected first but got third - url was http://localhost:8787/modules/first/versions/first

Patches

"v3.11.7" includes the change to fix this issue.

Workarounds

Don't use TrieRouter directly.

// DON'T USE TrieRouter
import { TrieRouter } from 'hono/router/trie-router'
const app = new Hono({ router: new TrieRouter() })

References

Router options on the Hono website: https://hono.dev/api/hono#router-option

Mitigation

Aliases

References