index.php in vtiger CRM before 5.0.3 allows remote authenticated users to obtain all usersβ names and e-mail addresses, and possibly change user settings, via a modified record parameter in a DetailView action to the Users module. NOTE: the vendor disputes the changing of settings, reporting that the attack vector results in a βYou are not permitted to execute this Operationβ error message in a 5.0.3 demo.