Zammad is a web based open source helpdesk/customer support system. Prior to 7.1.2, zammad's External Data Source feature, used to look up records from an external system, did not properly verify whether a user was allowed to see a specific ticket, user, group, or organization before including its details in a request to that external system. An authenticated user, including one with only basic customer access, could exploit this by referencing another record's ID, and thereby view details of tickets, customer accounts, teams, or organizations that did not belong to them. This issue is fixed in version 7.1.2.