Stefan Esser discovered that cacti, a front-end to rrdtool for monitoring systems and services, is not properly validating input passed to the rra_id parameter of the graph.php script. Due to checking the input of $_REQUEST but using $_GET input in a query an unauthenticated attacker is able to perform SQL injections via a crafted rra_id $_GET value and an additional valid rra_id $_POST or $_COOKIE value.