Package Instance

Improper Input Validation
If an application passes unvalidated user input as the file for which MIME type validation should occur, then arbitrary arguments are passed to the underlying file command.

Insufficient Session Expiration
The `PDOSessionHandler` class allows storing sessions on a PDO connection. Under some configurations and with a well-crafted payload, it was possible to do a denial of service on a Symfony application without too much resources.

URL Rewrite vulnerability
An issue in Symfony arises from support for a (legacy) IIS header that lets users override the path in the request URL via the `X-Original-URL` or `X-Rewrite-URL` HTTP request header. These headers are designed for IIS support, but it's not verified that the server is in fact running IIS, which means anybody who can send these requests to an application can trigger this. This affects `\Symfony\Component\HttpFoundation\Request::prepareRequestUri()` where `X-Original-URL` and `X_REWRITE_URL` are both used. The fix drops support for these methods so that they cannot be used as attack vectors such as web cache poisoning.

Symfony vulnerable to open redirect via browser-sanitized URLs
The `Request` class, does not parse URI with special characters the same way browsers do. As a result, an attacker can trick a validator relying on the `Request` class to redirect users to another domain.