An issue was discovered in Open Ticket Request System (OTRS) 7.0.x through 7.0.8. A customer user can use the search results to disclose information from their "company" tickets (with the same CustomerID), even when the CustomerDisableCompanyTicketAccess setting is turned on.
https://www.otrs.com/category/release-and-security-notes-en/
https://otrs.com/release-notes/otrs-security-advisory-2019-11/