CubeCart: Authenticated Arbitrary File Upload to RCE in REST Files API

CubeCart is an ecommerce software solution. Prior to 6.7.0, an Authenticated Arbitrary File Upload vulnerability exists in the REST API File Manager endpoint (POST /api/v1/files) of CubeCart. The endpoint allows any holder of an API key with files:rw permission to upload PHP source files into the web-accessible images/source/ directory, where they are executed by the web server. Combined with a path-traversal flaw in the same endpoint's filepath parameter, a single API request writes a webshell anywhere the webserver process can write — including the document root — yielding full Remote Code Execution. This vulnerability is fixed in 6.7.0.