WP Post Author < 4.2.0 - Unauthenticated Modification of the First User Account's Profile Fields

The WP Post Author WordPress plugin before 4.2.0 does not check that the account was created before updating its profile during front-end registration, allowing unauthenticated users to overwrite the display name, nickname and website of the first user account, which is normally the administrator, when a registration form declares one of those fields.