Litestar is an Asynchronous Server Gateway Interface (ASGI) framework. In versions prior to 2.22.0, an attacker can bypass the allowed hosts validation by omitting the Host header and supplying an X-Forwarded-Host header set to a whitelisted domain. The AllowedHostsMiddleware trusts the X-Forwarded-Host header as a fallback when the Host header is absent. Since X-Forwarded-Host is a client-controllable header, this enables host header injection attacks such as password reset poisoning, cache poisoning, and server-side request routing manipulation. Any application using AllowedHostsConfig is affected when deployed without a reverse proxy that strips X-Forwarded-Host, or when accepting HTTP/1.0 connections. This issue has been fixed in version 2.22.0.
| Version | Type | Source | Base | Exp | Imp |
|---|---|---|---|---|---|
| 3.1 | Primary | cve.org | 5.9 | — | — |
| 3.1 | Primary | cve.org | 5.9 | — | — |
| 3.1 | Secondary | GHSA | 5.9 | — | — |
| 3.1 | Secondary | ENISA EUVD | 5.9 | — | — |
| 3.1 | Secondary | NVD | 5.9 | 2.2 | 3.6 |