Chamilo LMS has an Open Redirect via Unvalidated 'page' Parameter in Session Course Edit

Chamilo LMS is a learning management system. Prior to 1.11.38 and 2.0.0-RC.3, an Open Redirect vulnerability in the session course edit page allows an attacker to redirect an authenticated administrator to an arbitrary external URL after saving coach assignment changes. The redirect also leaks the id_session parameter to the attacker's server. This vulnerability is fixed in 1.11.38 and 2.0.0-RC.3.