The user_id and device_id on the Ourphoto App version 1.4.1 /device/* end-points both suffer from insecure direct object reference vulnerabilities. Other end-users user_id and device_id values can be enumerated by incrementing or decrementing id numbers. The impact of this vulnerability allows an attacker to discover sensitive information such as end-user email addresses, and their unique frame_token value of all other Ourphoto App end-users.