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 8.0.10, 8.1.x before 8.1.5, and 8.2.x before 8.2.2 allow remote authenticated users to obtain sensitive information from a directory listing and possibly cause a denial of service (CPU consumption) via the force parameter to index.php/apps/files/ajax/scan.php.

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.

ownCloud Server before 8.0.9 and 8.1.x before 8.1.4 allow remote authenticated users to obtain sensitive information via unspecified vectors, which reveals the installation path in the resulting exception messages.

ownCloud iOS app before 3.4.4 does not properly switch state between multiple instances, which might allow remote instance administrators to obtain sensitive credential and cookie information by reading authentication headers.

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 Desktop Client before 2.0.1, when compiled with a Qt release after 5.3.x, does not call QNetworkReply::ignoreSslErrors with the list of errors to be ignored, which makes it easier for remote attackers to conduct man-in-the-middle (MITM) attacks by leveraging a server using a self-signed certificate. NOTE: this vulnerability exists because of a partial CVE-2015-4456 regression.

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.

ownCloud Desktop Client before 1.8.2 does not call QNetworkReply::ignoreSslErrors with the list of errors to be ignored, which allows man-in-the-middle attackers to bypass the user's certificate distrust decision and obtain sensitive information by leveraging a self-signed certificate and a connection to a server using its own self-signed certificate.

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.