Diactoros before 2.11.1 vulnerable to HTTP Host Header Attack
Date: 2022-07
Affected: composer/laminas/laminas-diactoros
Attack vector: xss
Category: vulnerability-disclosure
Severity: Medium
CVE: CVE-2022-31109
CWE: CWE-79
CVSS: 6.1 (CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N)

### Impact Applications that use Diactoros, and are either not behind a proxy, or can be accessed via untrusted proxies, can potentially have the host, protocol, and/or port of a `Laminas\Diactoros\Uri` instance associated with the incoming server request modified to reflect values from `X-Forwarded-*` headers. Such changes can potentially lead to XSS attacks (if a fully-qualified URL is used in links) and/or URL poisoning. ### Patches Any version after 2.11.0. Starting in laminas/laminas-diactoros 2.11.1, we have added `Laminas\Diactoros\ServerRequestFilter\FilterServerRequestInterface`, which defines the single method `__invoke(Psr\Http\Message\ServerRequestInterface $request): Psr\Http\Message\ServerRequestInterface`. Filters implementing this interface allow modifying and returning a generated `ServerRequest`. The primary use case of the interface is to allow modifying the generated URI based on the presence of headers such as `X-Forwarded-Host`. When operating behind a reverse proxy, the `Host` header is often rewritten to the name of the node to which the request is being forwarded, and an `X-Forwarded-Host` header is generated with the original `Host` value to allow the server to determine the original host the request was intended for. (We have always examined the `X-Forwarded-Proto` header; as of Diactoros 2.11.1, we also examine the `X-Forwarded-Port` header.) To accommodate this use case, we created Laminas\Diactoros\ServerRequestFilter\FilterUsingXForwardedHe


Mitigations:

Architectural layers (MAESTRO):