Piwik Authenticated RCE via Custom Plugin Upload

An authenticated remote code execution vulnerability exists in Piwik (now Matomo) versions prior to 3.0.3 via the plugin upload mechanism. In vulnerable versions, an authenticated user with Superuser privileges can upload and activate a malicious plugin (ZIP archive), leading to arbitrary PHP code execution on the underlying system. Starting with version 3.0.3, plugin upload functionality is disabled by default unless explicitly enabled in the configuration file.