An issue was discovered in Open-Xchange OX App Suite before 7.8.2-rev5. JavaScript code can be used as part of ical attachments within scheduling E-Mails. This content, for example an appointment's location, will be presented to the user at the E-Mail App, depending on the invitation workflow. This code gets executed within the context of the user's current session. Malicious script code can be executed within a user's context. This can lead to session hijacking or triggering unwanted actions via the web interface (sending mail, deleting data etc.).