Opencast has a partial path traversal vulnerability in UI config

Opencast is a free, open-source platform to support the management of educational audio and video content. In version 18.0 and versions before 17.7, the protections against path traversal attacks in the UI config module are insufficient, still partially allowing for attacks in very specific cases. The path is checked without checking for the file separator. This could allow attackers access to files within another folder which starts with the same path. This issue has been fixed in versions 17.7 and 18.1. To mitigate this issue, check for folders that start with the same path as the ui-config folder.