An issue was discovered in Open-Xchange OX App Suite before 7.8.1-rev11. The content sanitizer component has an issue with filtering malicious content in case invalid HTML code is provided. In such cases the filter will output a unsanitized representation of the content. 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.). Attackers can use this issue for filter evasion to inject script code later on.