Package Instance

Routes behind a firewall are accessible even when not logged in
Symfony does not process URL encoded data consistently within the Routing and Security components, which allows remote attackers to bypass intended URI restrictions via a doubly encoded string.

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.

Symfony2 security issue when the trust proxy mode is enabled
An application is vulnerable if it uses the client IP address as returned by the Request::getClientIp() method for sensitive decisions like IP based access control.

To fix this security issue, the following changes have been made to all versions of Symfony2:

A new Request::setTrustedProxies() method has been introduced and should be used intead of Request::trustProxyData() to enable the trust proxy mode. It takes an array of trusted proxy IP addresses as its argument:
```
// before (probably in your front controller script)
Request::trustProxyData();

// after
Request::setTrustedProxies(array('1.1.1.1'));
// 1.1.1.1 being the IP address of a trusted reverse proxy
```
The Request::trustProxyData() method has been deprecated (when used, it automatically trusts the latest proxy in the chain -- which is the current remote address):
```
Request::trustProxyData();

// is equivalent to
Request::setTrustedProxies(array($request->server->get('REMOTE_ADDR')));
```
We encourage all Symfony2 users to upgrade as soon as possible. It you don't want to upgrade to the latest version yet, you can also apply the following patches:

- [Patch](https://github.com/symfony/symfony/compare/fc89d6b...9ce892c.patch) for Symfony 2.0.19
- [Patch](https://github.com/symfony/symfony/compare/922c201...e5536f0.patch) for Symfony 2.1.4

Symfony vulnerable to command execution hijack on Windows with Process class
### Description

On Windows, when an executable file named `cmd.exe` is located in the current working directory it will be called by the `Process` class when preparing command arguments, leading to possible hijacking.

### Resolution

The `Process` class now uses the absolute path to `cmd.exe`.

The patch for this issue is available [here](https://github.com/symfony/symfony/commit/18ecd03eda3917fdf901a48e72518f911c64a1c9) for branch 5.4.

### Credits

We would like to thank Jordi Boggiano for reporting the issue and Nicolas Grekas for providing the fix.

Cross-Site Request Forgery (CSRF)
By default, a user's session is invalidated when the user is logged out. This behavior can be disabled through the `invalidate_session` option. In this case, CSRF tokens were not erased during logout which allowed for CSRF token fixation.

Improper Authorization
Security issue when parsing the Authorization header.