Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')
laminas-diactoros is a PHP package containing implementations of the PSR-7 HTTP message interfaces and PSR-17 HTTP message factory interfaces. 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. Since the `X-Forwarded-*` headers do have valid use cases, particularly in clustered environments using a load balancer, the library offers mitigation measures only in the v2 releases, as doing otherwise would break these use cases immediately. Users of v2 releases from 2.11.1 can provide an additional argument to `Laminas\Diactoros\ServerRequestFactory::fromGlobals()` in the form of a `Laminas\Diactoros\RequestFilter\RequestFilterInterface` instance, including the shipped `Laminas\Diactoros\RequestFilter\NoOpRequestFilter` implementation which ignores the `X-Forwarded-*` headers. Starting in version 3.0, the library will reverse behavior to use the `NoOpRequestFilter` by default, and require users to opt-in to `X-Forwarded-*` header usage via a configured `Laminas\Diactoros\RequestFilter\LegacyXForwardedHeaderFilter` instance. Users are advised to upgrade to version 2.11.1 or later to resolve this issue. Users unable to upgrade may configure web servers to reject `X-Forwarded-*` headers at the web server level. This vulnerability affects versions prior to 2.11.1.
CWE-444 - HTTP Request Smuggling
Entities such as web servers, web caching proxies, and application firewalls could parse HTTP requests differently. When there are two or more such entities in the path of an HTTP request, an attacker can send a specially crafted HTTP request that is seen as two different sets of requests by the attacked devices, allowing the attacker to smuggle a request into one device without the other device being aware of it. Such a vulnerability can prove devastating, for it enables further attacks on the application, like web cache poisoning, session hijacking, cross-site scripting, security bypassing, and sensitive information exposure.