Impact

=< undici@5.8.0 users are vulnerable to CRLF Injection on headers when using unsanitized input as request headers, more specifically, inside the content-type header.

Example:

import { request } from 'undici'

const unsanitizedContentTypeInput =  'application/json\r\n\r\nGET /foo2 HTTP/1.1'

await request('http://localhost:3000, {
    method: 'GET',
    headers: {
      'content-type': unsanitizedContentTypeInput
    },
})

The above snippet will perform two requests in a single request API call:

1. http://localhost:3000/
2. http://localhost:3000/foo2

Patches

This issue was patched in Undici v5.8.1

Workarounds

Sanitize input when sending content-type headers using user input.

For more information

If you have any questions or comments about this advisory:

• Open an issue in undici repository
• To make a report, follow the SECURITY document