In Invoice Ninja before 4.4.0, there is an unsafe call to unserialize() in app/Ninja/Repositories/AccountRepository.php that may allow an attacker to deserialize arbitrary PHP classes. In certain contexts, this can result in remote code execution. The attacker's input must be hosted at http://www.geoplugin.net (cleartext HTTP), and thus a successful attack requires spoofing that site or obtaining control of it.