Chamilo is a learning management system. Prior to version 1.11.30, a logic vulnerability in the friend request workflow of Chamilo’s social network module allows an authenticated user to forcibly add any user as a friend by directly calling the AJAX endpoint. The attacker can bypass the normal flow of sending and accepting friend requests, and even add non-existent users.

This breaks access control and social interaction logic, with potential privacy implications. This issue has been patched in version 1.11.30.