An issue was discovered in the registration API endpoint in 42Gears SureMDM before 2018-11-27. An attacker can submit a GET request to /api/register/:email, where :email is a base64 encoded e-mail address, to receive confirmation as to whether a user account exists in the system with the specified e-mail address. The request must be made with an "apiKey" value in the "ApiKey" header.