ZoneMinder is a free, open source closed-circuit television software application. Prior to 1.38.3, the exportEvents() function concatenates the attacker-controlled exportFile request parameter into a shell command without neutralizing shell metacharacters when an authenticated user with View Events or View Snapshots permission submits an event export request with a crafted exportFile value, a valid CSRF token, and exportDetail enabled. The affected components are exportEvents(), exportFile, web/ajax/event.php, web/skins/classic/includes/export_functions.php. In this attack mechanism, the crafted exportFile value reaches the trailing directory argument of a tar or zip command executed by exec(). The attacker can execute arbitrary operating system commands as the web server user. This issue is fixed in version 1.38.3.