Open Ticket Request System (OTRS) before 2.4.0-beta2 does not properly enforce the move_into permission setting for a queue, which allows remote authenticated users to bypass intended access restrictions and read a ticket by watching this ticket, and then selecting the ticket from the watched-tickets list.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.