FileRun 2019.05.21 allows css/ext-ux Directory Listing. This issue has been fixed in FileRun 2019.06.01.
https://github.com/EmreOvunc/FileRun-Vulnerabilities/issues/3
https://github.com/EmreOvunc/FileRun-Vulnerabilities/
https://emreovunc.com/blog/en/FileRun-DirectoryListing-2.png