Cross-site scripting (XSS) vulnerability in the OCS discovery provider component in ownCloud Server before 7.0.12, 8.0.x before 8.0.10, 8.1.x before 8.1.5, and 8.2.x before 8.2.2 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors involving a URL.

ownCloud Server before 7.0.12, 8.0.x before 8.0.10, 8.1.x before 8.1.5, and 8.2.x before 8.2.2, when the "file_versions" application is enabled, does not properly check the return value of getOwner, which allows remote authenticated users to read the files with names starting with ".v" and belonging to a sharing user by leveraging an incoming share.

The files_external app in ownCloud Server before 7.0.9, 8.0.x before 8.0.7, and 8.1.x before 8.1.2 allows remote authenticated users to instantiate arbitrary classes and possibly execute arbitrary code via a crafted mount point option, related to "objectstore."

ownCloud Server before 7.0.8, 8.0.x before 8.0.6, and 8.1.x before 8.1.1 does not properly check ownership of calendars, which allows remote authenticated users to read arbitrary calendars via the calid parameter to apps/calendar/export.php.

Directory traversal vulnerability in ownCloud Server before 8.0.6 and 8.1.x before 8.1.1 allows remote authenticated users to list directory contents and possibly cause a denial of service (CPU consumption) via a .. (dot dot) in the dir parameter to index.php/apps/files/ajax/scan.php.