Symfony2 improper IP based access control

Summary

Damien Tournoud, from the Drupal security team, contacted us two days ago about a security issue in the Request::getClientIp() method when the trust proxy mode is enabled (Request::trustProxyData()). 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