ownCloud owncloud/client before 2.9.2 allows Resource Injection by a server into the desktop client via a URL, leading to remote code execution.

ownCloud owncloud/client before 2.7 allows DLL Injection. The desktop client loaded development plugins from certain directories when they were present.

ownCloud Desktop before 2.2.3 allows local users to execute arbitrary code and possibly gain privileges via a Trojan library in a "special path" in the C: drive.

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 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.