elFinder is an open-source file manager for web, written in JavaScript using jQuery UI. Prior to 2.1.67, elFinder contains a command injection vulnerability in the resize command. The bg (background color) parameter is accepted from user input and passed through image resize/rotate processing. In configurations that use the ImageMagick CLI backend, this value is incorporated into shell command strings without sufficient escaping. An attacker able to invoke the resize command with a crafted bg value may achieve arbitrary command execution as the web server process user. This vulnerability is fixed in 2.1.67.